Lister Engine Forum
General Category => General Discussion => Topic started by: mobile_bob on November 12, 2006, 07:07:15 AM
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sometimes i am known for being like a dog on a bone, most especially when i am trying to get to an answer to a specific question.
being told that is just the way it is, rarely will suffice, usually i need to know the why's or the why not's
this is usually compounded by gut feelings, observation, experience and by intuition, basically if it don't feel right, i begin to question.
on a related post i asked whether a lister/oid was a machine, got no answers, so i will for the sake of an arguement take the position that the engine is not a machine,
until it is coupled to a generator it then becomes part of a machine.
now our genset has become a machine by virtue of common definition, and thru much debate here the common consensus is the engine must be rigidly mounted to the frame, and commonly the genhead is also rigidly bolted to the frame, thus the engine, genhead and frame all become a machine known as a genset.
(i really am going somewhere with this)
in Audel's mechanical trades pocket manual, 4th edition, the following:
machinery mounts, in short
"in manufacturing plant , machine's are no longer rigidly mounted to the floor..."
"because of the ever increasing variety of industrial machines, the problems associated with vibration, shock, and noise in addition to that of mobility have become important considerations"
" shock and vibration damping machine mounts, eliminate the need to anchor a machine to the concrete floor..."
and this (which gives rise to my continued search for a concise answer):
"another very important benefit resulting from the use of vibration damping mounts is the reduction of internal stresses in the machine"
"when vibrating equipment is rigidly bolted to the floor, an amplification of internal stresses occurs. ...the results often are undue wear on brgs and related parts"
i find the more i dig, and the more i read, the more i question
so if the lister/oid is not a machine then it can be mounted to concrete rigidly, if it is part of a genset it now becomes a machine, a machine bolted directly to concrete will have its vibration amplified with resulting stresses on the machine, which the lister/oid is part of ....
there simply has to be another explanation for the recommendation by lister to use a block of concrete
what are the options
1. the concrete block is an intregal part of the engine design? there is no logic to support this, no documentation and certainly some issue with amplification
2. the concrete block is used as a dead weight to secure a less than perfectly balanced engine? likely? certainly possible
3. the concrete block is of sufficiently safe design so as to negate the need for lister to have to review engineering of hundreds of mounting schemes? most likely
i fully realize that this topic has been beat to death, but i am still trying to get to the bottom of the issue. if this topic stresses anyone my appologies, feel free to not respond.
my purpose of bringing this all back up again is one of theory.
bob g
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Bob,
I spent a couple of years responsible for a very impressive, heavy, FAST Amada Pega 345 Turret punch press. It could punch 4" holes in 11ga. 304ss. Shook the building. It "came" from Amada with four "feet" that it sat on and allowed leveling. The "feet" were rubber faced. Moved it once. Both places, never "walked". I Sharpied the feet to keep track...
Your #2 and #3 are to me very plausible.
Kevin
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Concrete block or raft mounting of engines has been around since the very early days of big engines, so anyone building engines had a lot of previous data/information to go on. Ruston & Hornsby, Crossley, National and others all supplied drawings for foundations for their engines, even the smallest.
It seems that it is relatively recently that flexible (as opposed to rigid) mountings became a part of the system, and even then still with the large foundation structure in place.
It seems that the smaller engines didn't have the need for flexibles until we got into the more recent use of small portable generators, and then it was more to stop the unit walking across the florr than anything else.
I believe that Lister and Petters both recommended heavy foundations more for the absorbtion of vibration than anything else, and like most things of that era they were probably over-engineered.
Most Lister and Petter engines and certainly Ruston, Crossley, National etc made portable engines on trolleys/carts that were relatively light in comparison with foundation blocks, and they did move around a lot when working, most needing chocks on the wheels or other restraining devices.
I don't have any real thoughts on the "why's and wherefores", as it is not a subject close to my heart, but there is an awful lot of information in the older engine books, including a 5-volume set on diesels by the American Technical Society which I have, that quotes a lot of figures and formulae for foundation construction from 50hp up to 500hp.
Peter
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while this subject is not one that is particularly close to my heart, getting to the bottom of the issue seems prudent, mainly because of broad application of the theory.
Guy Fawkes has made the assertion that the concrete base was a consideration in the original lister design.
while i have the utmost admiration for GF's input, thoughts, and knowledge, i need to get a better understanding of the need for the base.
there is the theory of moving the center of mass, into the block of concrete and in theory i can accept that as fact.
with every action there is an equal and opposite reaction, this too i accept as physical law
the concept that vibrations can me amplified in a rigid concrete base and returned to the machine in higher amplitudes is something i can also accept.
until i can arrive at an understanding of why there was a recommendation or statement that a concrete block of specific dimensions, i find it hard to accept.
while i have theories, idea's and suspicions, i realize that none of them is based in anything others than smoke or feelings
until i can find text that supports in physics or science the math/geometry or whatever that shows the need for the concrete block i am faced with accepting the recommendation on blind faith... which is fine for religion, but not something i have room to accept in day to day life.
anyone find some text or doc's that specifiy and explain the need for concrete, other than "trust me" ?
bob g
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Just thinking here and considering the times these got started, maybe it was a way to keep users from putting the engines on flimsy wooden bases and possibly a more or less common size block to pour. So the spec. would get people to use a safer installation and give a certain CYA to the Lister co.
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i suspect there is some credance to the old CYA, but this is only just another theory not something concrete (no pun intended)
so much in engineering is built up on empirical evidence, and once something has been proven out to be either sufficient and/or expedient it is only human nature to keep on with the original plan
boiled down we have basically 3 schools of thought
1. in support of concrete
a. it was and is an intregal part of the original design
b. the concrete base was an engineered part of the engine
c. forces/vibration are moved from the engine proper into the concrete base
2. the use of concrete as a marketing ploy
a. lister built engines and found them to work ok on a concrete base, negating the need for expensive and comprehensive balanceing
b. turn a negative into a positive (marketing tool) by making the claim that the concrete is an intergal part of the engine design.
c. homogenize the mount to one approved system, negating the need to check an approve other designs
3. the use of concrete may not be a good thing
a. forces/vibrations might be amplified and returned to the engine as destructive or life shortening forces
b. vibration and noise will be transmitted to other parts of the structure, other parts of the machine or other components
c. relocation of the complete unit will be difficult if the need arrises
and the list goes on......
the problem as i see it is,,, each of the schools of thought have equal merit, and none has an overriding basis in fact
basically because there has been no engineering figures to support any one of the three to any conclusive extent.
i have read countless books on the subject, over the last few months, and have yet to find anywhere by anyone that one system is the one true and only successful system.
it would appear that in the beginning there were stationary engine's and as such were mounted on concrete bases because of the ability to fabricate large heavy bases easily out of the material without need for expensive manpower, specialized machinery/tooling, and the fact that everyone of consequence was doing it that way.
just because its the way it has always been done, does not make it necessarily right or wrong.
then came the automobile and rigid mounted engines caused vibration to be transmitted to the passenger compartment, this is where resilient mounting came of age, and that was basically because the manufactures were trying to make their offerings more acceptable to the consumer. meanwhile the stationary engine's remained rigid mounted, why change when no one really complained, and afterall that is the way it has always been done,,, right?
in recent years consumers of stationary equipment are trying to do more with less, usually less space, which forces people and their related office space within the same building as the offending machinery, thus the need for resilient mounting and the proliferation of isolating technologies. now machines that were once always mounted rigidly to concrete monolithic blocks are routinely mounted resiliently without hard connection to the concrete floors and foundations. hammer mills, punch presses, drop hammers, engines, etc are now mounted resiliently when in the past they were always hard mounted.
so what has changed? besides the demand for mitigation of vibration? the machines have not changed, if anything they are lighter than they were 50 or 100 years ago all the while doing the same work or in many cases heavier work.
is it not possible that the discussion now would be to blast the guy that wanted to mount his engine to a ton of concrete had stationary engines 100 years ago been routinely mounted resiliently? would the assertions be, the resilient mounts were an intregal part of the original engine design, and if you negate them you do so at your engine peril?
i really wonder, and short of some documentation by any engine manufacture showing the engineering of a concrete base being an intregal part of their engine, i will continue to question.
bob g
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sigh....
You had your answer, as did others, trouble is nobody likes the answer.
(http://www.popartuk.com/g/l/lget4001.jpg)
You know a lister has a centre of mass above the crankshaft axis, you know where the centre of mass of a block of concrete is, you can work out where the centre of mass of the combined system is, and you can work out how shifting this shifts and alters all the vectors of force from the reciprocating components, and when you work it out you will see how loads are reduced on the rotating machinery.
Here is an exact parallel example, the moon, being in orbit, is in a constant state of acceleration towards us, despite the fact that its angular velocity doesn't change, it is ALWAYS accelerating, same goes for satellites, earth around sun, etc etc etc.
This is easy enough to prove, you work through the math F = ma etc, and when you do that math you realise it is the only possible answer, no matter how counter intuitive or stupid or against common sense it seems.
When you work it out and understand it you realise that common sense gave you the wrong answers because common sense was founded on incorrect principle, same as the heliocentric model of the world and start moving on crystal spheres.
Newton was a genius because he did not follow common sense, he worked the numbers until he had answers that were always computationally correct............
Eratosthenes calculated the diameter of the earth by observing shadows in wells during the solstice about 230 BC
Galileo 1564-1642 calculated the acceleration due to gravity in about 1600 AD
Newton 1642-1727 calculated his second law of motion, F = ma about a hundred years later
Cavendish 1731-1810 used this to weigh the mass of the earth about fifty years later
All these people were polymaths, weighing the earth would have been enough to make cavendish famous, but he also worked out that water was oxygen and hydrogen, discovery of hydrogen, electric potential, capacitance, dielectric constant, ohms law, wheatstones law, coulombs law, again, any one of which would be a rare achievment for anyone else.
It took people like these to see beyond "common sense" and work out what was really going on.
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Now, I can PROVE to you that the moon is always accelerating, even though its speed never changes, and how we go from force through right angle vectors to speed and right angle vectors to acceleration, BUT YOU HAVE TO LEARN THE MATH.
THERE IS ABSOLUTELY NO ALTERNATIVE.
When you learn this math you can then go on to prove that shifting the centre of mass outside the radius of the moving parts in our engine lowers the stresses on said parts.
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WHEN you learn the math you will see that the moon once rotated, but tidal forces slowed it down until it locked into earth, and you will see that that process also had to alter the radius of the moons orbit, it all becomes beautiful and elegant.
If you do not learn the math the moon will not fall out of the sky, but you will never get a job at NASA and you will never get to walk on the moon.
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Bob, when I want to be I can be a FUCKING good engineer, but I fall so far short of even lesser gods like henry ricardo and james watt and otto diesel and a string of other names whose boots I am not fit to lick it ain't even funny, and THEY worshipped people like newton and cavendish and maxwell etc.
Do you know how many patents I hold bob?
none
Do you know how many things I have truly designed bob, as opposed to assembling other peoples designs and tweaking them to fit?
none
I can go out and design a brand new internal combustion engine tomorrow, go out and build it, and it will run to spec, and I mean every last component and structure inside it will be bespoke and brand new and quite unique.
But there will not be a single component that your average mechanic will not immediately recognise for what it is.
I could get really exotic and use a swash plate instead of crankshaft and con rods, I could use aspin heads instead of poppet valves, but a good mechanic would still recognise everything for what it was.
Doug could go out and design a new electric mine train, same story, he doesn't need to invent or even truly understand ohms law, coulombs, reactance, induction or anything else, he doesn't even need to do any math, just use his judgement, and it will still work after some sort of fashion.
But to REALLY design it he will need to learn and understand all those laws, then he can build it to spec, then he can say yeah it will have a drawbar pull of 20,000 lbs and a power consumption of X and a thermal rejection of Y and a service interval of Z hours.
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Outside is my car, one of these.
(http://www.carsurvey.org/images/peugeot_405_1.jpg)
1.9 litre 4 pot naturally aspirated no electronics diesel, drive is nicely and it will do 60 mpg at 60 mph (imperial gallons)
They are legendary and hugely popular as taxis, 300,000 miles on a motor is not uncommon.
300,000 miles at 50 mph is 6,000 hours.
6,000 hours is absolutely nothing, inconsequential, to a Lister CS or to any other pukka stationary engine.
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I've told you and others, for a fact, that the concrete block is an integral part of the design, because it shifts the centre of mass and so shifts the vectors.
You have NO OPTION but to either accept that or go learn the math, OR continue believing that the moon cannot be constantly accelerating because it is not speeding up, common sense says so.
Buzz aldrin and neil armstrong did not walk on the moon via common sense, lister did not design the cs series via common sense, they did the math, they did the engineering.
Non engineers were amazed when apollo landed on the moon within a couple of seconds of when it was supposed to before it had even left the launchpad, engineers were not, engineers knew it was not a bus going down a highway, engineers knew it has to take precisely that time if it was taking that route.
F = ma, F = GmM/r2 = ma, GM/r2= a, M = ar2/G, M = 9.8 x (6.7 x 106)2/6.7 x 10-11 = 6.0 x 1024 kg (mass of the earth as determined by cavendish) he was less than 1% out.
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seeking an answer? no, you are seeking an easy and acceptable to you answer with the minimum effort.
which is Ok and quite human.
but it is not seeking an answer.
eratosthenes, galileo, newton, cavendish, they were seeking answers.
all we have to do is follow in their footsteps and learn
if we are not prepared to do that we will never learn.
I am not prepared to follow in the footsteps of watson and crick, so I have no right to seek answers about dna, I just have to accept it exists just as they say it does, and I have to accept the glib answers that geneticists must give to laity such as myself when I ask about dna fingerprinting and matching allele bases, because I am not prepared to study the subject long enough to learn the proofs.
I can fuck and make babies, as it happens there is a baby due in a few weeks, doesn't make me a geneticist, so I have no say in eye colour, genetic defects, susceptibility to cancer, or anything else, even if I wanted to or thought I should play god.
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I've always been in awe of Newton and Faraday and those of their ilk. As far as understanding what Newton said about laws of motion - I get that. What amazes me is what kind of mind can take 10 steps back and figure out the relationships and then turn around and come up with the formulae to express it and have it work perfectly. I'd have loved to have met Newton but I'm sure he would consider me a dullard in comparison if he had to explain something that was so obvious to his mind.
Congratulations on the impending birth Guy, I hope you are stockpiling some sleep now.
Regards
Robert
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Guy:
first of all let me give you best wishes on the birth of your child, get ready tho' you will be asked "why" millions of times by the little bugger for many years.
now to the point.
your analogy or reference if you will to the moon, tides, its orbit, etc is an interesting tangent to the question at hand.
your use of names (name dropping if you will) while being quite impeccable as a group, does not address the question at hand.
The fact that you do or do not hold patents does not take away from your intelligence or for that matter add to your intelligence, or anyone else's for that matter.
as far as math/formulae etc.
thru careful observation or experimentation certain patterns develop
patterns can be expressed mathematically
mathematically expressed patterns are at times proven out to become formulae
through formulae one can determine an outcome
interestingly i can find formulae for every facet of an engine, from volumetric efficiency to mach index's, from cylinder pressures to flame propagation and ignition timeing, connecting rod ratio's to chamber design, 1st, 2nd, 3rd, etc harmonics to resilient mounts, literally every part and parcel of an engine can and has been analized and expressed in some form of formulae, .... save one!
that being any formulae relating to the concrete rigid mount, showing the vectors, angles, math etc to clearly not only illustrate what is happening but providing proof of concept.
doesn't this ommission (sp) seem odd?
seriously and respectfully, can you or anyone direct me to the text or some formulae outlining the use of concrete as the engine base, other than some directive to do so?
it would seem to me as it should you and others that some reference material with the requisite math/formulae should exist somewhere
failing that i am left to believe that lister simply poured a concrete base that looked about right for their engine, found it to work for what they intended and simply left it at that.
why am i to accept that there was some sort of theory, math and formulae in use to determine the size of said block without some form of documentation?
mr ricardo certainly was a master and as such documented his work, is he somehow inferior to the lister engineer's? did he have to document his assertions and lister did not?
are you placing lister engineers on a higher alter, someplace above question?
i believe in things i cannot prove, such as God.
i am unwilling to place lister on that plane.
bob g
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I'll keep it short!
are you placing lister engineers on a higher alter, someplace above question?
i believe in things i cannot prove, such as God.
i am unwilling to place lister on that plane.
bob g
I am also unwilling to place lister on that plane. But will accept any factual evidence!
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seriously and respectfully, can you or anyone direct me to the text or some formulae outlining the use of concrete as the engine base, other than some directive to do so?
bob, you've had your answer a dozen times over, go and do the math, that IS the answer.
concrete was chosen simply because it is dead simple to do and always get pretty similar results, concrete will last a thousand years, we know that because there is thousand year old roman concrete right here.
if you can do the math you can substitute lead for concrete, or zinc, or pig iron, because you can do the math and work it out, even depleted uranium.
if you can't do the math use concrete.
you say I am misdirecting you with talk of the moon constantly accelerating but never changing speed, I am not, I'm trying to show you with another example because you appear to be dead set against seeing the answer being laid before you.
the moon accelerating and vibration in a lister are calculated by exactly the same math.
GO AND LEARN THE BLOODY MATH, IT IS THE ONLY ANSWER.
then you'll understand that as remarkable as newton and galilieo and cavendish were, their math did NOT solve a whole bunch of problems, such as three body celestial mechanics, kepler did that.
newtons laws work on fixed radius, there might as well be a crankshaft attaching earth and moon, that's why newtons laws work. well, they do until you look real close and see the effects of sun and other planets preturbing them.
unless you can understand mathematically enough to at least grasp mathematically the stuff on the following link (you need java) then by definition you cannot understand mathematically why a concrete block is good for lister longevity
http://faculty.ifmo.ru/butikov/Projects/Collection.html
here endeth my discussion on the subject
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interestingly i can find formulae for every facet of an engine, from volumetric efficiency to mach index's, from cylinder pressures to flame propagation and ignition timeing, connecting rod ratio's to chamber design, 1st, 2nd, 3rd, etc harmonics to resilient mounts, literally every part and parcel of an engine can and has been analized and expressed in some form of formulae, .... save one!
I'm not addressing your main argument one way or the other Bob, but I don't think this particular part is true. If it were, there would be no need to experiment with engines as one could predict the results of a given change.
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Guy:
"you say I am misdirecting you with talk of the moon constantly accelerating but never changing speed, I am not, I'm trying to show you with another example because you appear to be dead set against seeing the answer being laid before you."
perhaps your conclusion that i am dead set against seeing the answer, is based on either you being dead set against answering my question or more likely i am not clear in defining my question.
for now i will assume i am at fault in not defining or relating my question in specific terms.
let me preface my question
i can find math and formulae to determine optimum cam profiles, valve opening, diameters, runner lengths etc.
i can find math and formulae to determine optimum bore to stroke ratio's, con rod ratio's etc
i can find math and formulae to determine proper dimensions and materials for every component of an engine
i can find math and formulae for things as basic as the motor mounting bolts, grade, diameter, thread pitch etc.
i can find very complex math and formulae for determining vibration, harmonics of ever order
i can find math and formulae from the most simple fastener to the most complex theoretical for each and every part of the engine proper.
but not one digit of math or formulae on design considerations of a concrete base?
am i to believe that the math/formulae for the concrete base is so simplistic so as not to merit mention anywhere? or...
so complex that mear mortals cannot conceptualize, or compute it, so this is why there is no reference to it? or....
something in between that just happened to slip through the cracks, everyone forgot to make mention of the math/formulae?
is it something that is so carefully guarded that i would have to be killed if i was to be shown the math/formulae?
comeon Guy, seriously now....
there is no way that an engineer faced with having to determine the proper sizing of a concrete base would have to go thru some planetary analysis to come to
the design criteria.
there simply has to be a more direct route or set of variables that can be plugged into a formulae to determine the proper dimensions
variables such as
rpm, 4 stroke/2stroke, weights, physical dimensions of the engine, crank center height, mounting dimensions to name a few
you would have to know all these a many more even if you were to work thru some planetary formulae and then adapt that result to your application.
this is a big bone to swallow on blind faith,
now if i could find some text or mention of formulae that said some version of:
(rpm/ weight * center height )/ the square root of blah blah blah, the result of which is X
then plug X into the second formulae where base length is .761*X/ ou812,, blah blah blah
i hope you see where i am going with this?
if (and i still say if), the concrete base was engineered then there should be some reference to the use of math/ formulae somewhere
i don't have to do obscure math to figure every other part of the engine, there are clear and concise formulae for each part
i dont have to track the path of one of pluto's moons to determine optimum injection timing, valve sizing etc
why do i have to do obscure math for the concrete base?
is the concrete base a "black" art and not science or math
do i need an astrologer? i witch doctor?
where is the friggin beef?
specifically and very narrowly stated
"WHERE IS THE FORMULAE FOR DETERMINING THE PROPER DIMENSIONS OF A CONCRETE BASE FOR A GIVEN ENGINE"
BOB G
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I said I wasn't going to answer this question any more, but I am, for two reasons.
1/ I have to sit here and wait for someone to turn up so I am bored.
2/ It may be that the root of this problem is one of simple communication.
Go look at http://faculty.ifmo.ru/butikov/Projects/Collection4.html (you have to enable java etc)
Both views show the same thing, one from the centre of mass, one from one body as the centre.
You cannot "see" centre of mass, so you will always, via common sense, see the lower view, which is technically incorrect.
so, to your question, again.
You go and calculate the various vectors and forces acting on your lister cs, newtons second law f=ma etc etc etc etc.
You look at this result from the point of view of the top animation above, not the common sense lower animation.
You will see that many of the forces generated are acting within the radius of the crank, which is not good.
You know from your calculations that all you have to do to alter these various vectors and forces and move them too is alter the centre of mass of the whole shebang.
Easiest way to alter the centre of mass of the whole shebang is add mass externally, easiest way to consistently do that is add concrete.
Your calculations will tell you how much mass you need to add, how far it needs to be from crankshaft axis, and at what bearing.
Factor in density of concrete (or depleted uranium, or lead, or cast iron, or any other suitable material) and you will get dimensions.
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The moon is CONSTANTLY ACCELERATING, yet, apparently paradoxically, the moon is travelling at a CONSTANT VELOCITY in its orbit.
If you do not GET this, if you do not GET that acceleration is rate of change of velocity in a given direction, etc you have NOT worked with the math and done force vectors to velocity vectors to acceleration vectors to etc etc etc.
If you have not ever actually done the math you will not ever actually understand the answer.
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ONLY BASIC MATH works like a simple spreadsheet, punch in a few numbers and get an answer out, numbers that make sense.... if it takes ten men working eight hours a day three days to dig a trench six feet deep and three feet wide and sixty feet long how long does it take five men to dig a hole ten feet in diameter and ten feet deep.
this is BASIC MATH.
Ask Mr Belk about ballistics, if you want to hit a target 6000 yards away with an intervening building 300 feet high with a projectile weighing 4 pounds there is only one solution for a given muzzle velocity.
this is NOT BASIC MATH
There are two sorts of people who will actually hit that target in practice.
The ones is forty years of experience.
The ones with ballistic computers, not spreadsheets, ballistic computers.
You are making some FUNDAMENTAL errors here.
i can find math and formulae to determine optimum cam profiles, valve opening, diameters, runner lengths etc.
sure you can, except when you try and use them from base data with real world examples you will NEVER as long as you have a hole in your ass come up with a cam profile that is actually fitted to your sample engine, or valve lift, duration, etc etc.
i can find math and formulae to determine optimum bore to stroke ratio's, con rod ratio's etc
sure you can, if you first ignore reality and define some arbitrary optimum which is anything but....
go on, stick a lister CS into your formulae and see what you get
i can find math and formulae to determine proper dimensions and materials for every component of an engine
sure you can, as long as you dont actually try and build an engine from that data and that data ONLY and do not do anything except stop dead the instant you find a bit of data not produced by your calculations, which in reality will stop you before you even start making the mould to pour the first billet before you even think about machining to size
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Bob, here is a challenge for you. It will take you some time, but it used to be a basic apprentice task.
Get yourself a lump of nearly pure copper at least 1.2 inches in x , y, z dimensions.
You will of course be able to calculate exactly the mass of a perfect one inch cube of this material, and of course you will be able to calculate perfectly the volume.
Using a vice and a file, for nothing else is needed, transform this lump of copper into a perfect one inch cube, accurate to less than 2 thou, it will take you some time, perhaps a full day.
A micrometer will tell you if all three opposing sides are parallel and between 0.998 and 1.002 inches.
A machinists square and silk thread will tell you if it is square.
A displacement flask will tell you if it is between 0.994 and 1.006 cubic inches in volume.
You are not a young apprentice, so it should not take you a week and 5 or 6 wasted pieces of work before you "get" how to do it. You should be able to do it first time in a single day.
WHEN you have done this, you will understand the materials properties of copper in ways that didn't even register on the radar today, even though you almost certainly think you know "enough" about copper.
The MATH is the same, you THINK you understand enough about it because you have found a few forumula of basic math that you think makes sense to you and give you sensible results, even though you have not compared any of them to real world results.
Do you MATH apprenticeship in the same way and the same understanding will dawn, there is no shortcut.
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many years ago I released a freeware marine propeller calculator for displacement hulls based on a spreadsheet, with the various things spread over different pages of the sheet so people could follow the working and learn and not bug me with questions.
I created it after many years in the industry and checked it with a real world sample of three figures (eg hundreds) of actual boats where I knew the data for a fact, the results, as it said, were suprisingly good, but almost never matched what was actually fitted, because I was using all the correct formulae, which neatly omits some tupperware yacht builder wanting to fit a tiny engine to maximise internal cabin volume and a tiny propeller to minimise drag while sailing.
follow the formulae and you can always get off a lee shore, and make hull speed in most seas too.
nobody in recreation boat land follows the formulae
deep sea fishing boats, admiralty pinnaces, things like that match it excellently.
so an analogy of what we have here is a hobby sailor (you) saying you think the trawler hull was never designed to be a part of the engine bed, and until and unless the shipyards who have been building trawlers for generations can show you why you shouldn't use glassed in softwood beams and isolastic mounts to put a trawler engine in your flexible lightweight tupperware hull you ain't buying it, so they point you towards wake factor, block coefficient, analysis pitch, modulus of elasticity of the shaft, and you still claim it ain't a good enough answer.
it IS a good enough answer for THEM, and THEY build trawlers, YOU don't.
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you can put your trawler engine in your tupperware boat, and probably not sink or kill yourself, because you won't be going deep sea fishing
that does NOT make you right and them wrong.
if you try and go deep sea fishing you will, sooner or later, sink and kill yourself
Be honest.
Almost none of you have any requirement for 100,000+ hours major service intervals, a 10,000 hour engine will do you.
LISTER WOULD NO MORE BE IN YOUR BUDGET THAN ARROW IS TODAY.
If you want to do it right do it the lister way and bolt that fucker solid to a big block (not slab) of concrete.
If you want to understand why that is right then sit down and study the math for a few weeks or months and learn it.
there are no other options. there are no shortcuts.
I don't know if mr belk is a seat of the pants gunsmith or if he knows all the math too, it doesn't make any difference, I can learn all the math within a year, and he could still lose me for dead within 60 seconds of starting work, and consider me bloody dangerous within 5 minutes, there are no shortcuts.
studying the math for a year will do one thing and one thing only, it will allow me to understand what he is saying when he says that this part of this gun needs to made just so, there are no shortcuts.
people who are not prepared to study the math and do the apprenticeship have two option, pop into guns-r-us and buy a ruger blackhawk in 44 mag because dirty harry had one and dirty harry is cool, or go to jack with a wad of cash and tell him what sort of shooting they want to do, and end up with a gun for life.
Lister were the same, same thing applies.
there are no shortcuts
now I really am done answering this question.
(until and unless someone demonstrates that they have learned and done the math and then ask a question based upon that)
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The moon is CONSTANTLY ACCELERATING, yet, apparently paradoxically, the moon is travelling at a CONSTANT VELOCITY in its orbit.
If you do not GET this, if you do not GET that acceleration is rate of change of velocity in a given direction, etc you have NOT worked with the math and done force vectors to velocity vectors to acceleration vectors to etc etc etc.
If you have not ever actually done the math you will not ever actually understand the answer.
==========================
Getting a little sloppy with the word "velocity" there Guy.
I know you know this but for those who skipped intro science class.
Velocity is one of those words that is very commonly used carelessly, and so has become synonymous with the word speed when used by the general population.
However when you are talking celestial mechanics velocity is a vector (it includes both speed and direction) and speed is scalar (no direction) so the velocity of the moon is always changing but the speed component of the vector is constant (assuming a perfectly circular orbit or limited resolution).
http://whatis.techtarget.com/definition/0,,sid9_gci755044,00.html
Using a vice and a file, for nothing else is needed, transform this lump of copper into a perfect one inch cube, accurate to less than 2 thou, it will take you some time, perhaps a full day.
A micrometer will tell you if all three opposing sides are parallel and between 0.998 and 1.002 inches.
A machinists square and silk thread will tell you if it is square.
A displacement flask will tell you if it is between 0.994 and 1.006 cubic inches in volume.
Don't need the square, and the displacement flask should just be a sanity check on your measurements and calculations.
1. Use the three surfaces method to get one truly flat surface to start with.
2. File the opposite surface parallel with the first.
3. Repeat for the second set of parallel surfaces, eye balling it square and making the distance a little big.
4. You can now use the mic. to measure across the edges and work the second set into square and to size with the first.
5. Repeat for the third set of surfaces but make square with both the first and second set.
You will need a very light touch to keep from squishing flats on the edges with the mic..
There has been mention of the great personalities of science and engineering. What made these people great is not raw intelligence or the willingness to look at things differently then what is commonly known, both are fairly common by themselves, but the combination is not, also need a good deal of luck. If certain people in Watt's early life would have died he could have easily been just another name lost in the mists of time. And someone else or combination of others would have stepped in a made virtually the same contributions in almost the same time frame, there were a lot of people working on the problem at that time as seen by the number of patent lawsuits, Watt was in on a number of them and from both sides.
A little on Newton I found interesting.
In 1936 John Keynes purchased a cache of Newton's writings that the Royal Society had said were of no scientific value. After reading thru the notebooks Keynes said in a lecture to the Royal Society club that Newton was not the first of the age of reason, but the last of the magicians.
Research Newton with respect to religion and alchemy.
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There has been mention of the great personalities of science and engineering. What made these people great is not raw intelligence or the willingness to look at things differently then what is commonly known, both are fairly common by themselves, but the combination is not, also need a good deal of luck.
I don't disagree with what you say here, but I'd put persistence and dedication higher on the list. Newton had an extraordinary capacity to concentrate. Einstein made several comments to the effect that others could equal his accomplishments if they matched his dedicated. Mozart is the archetypal prodigy, but what is lesser known is that his father pushed him very hard from early on. By the time he wrote "Twinkle Twinkle Little Star" at age four he had something like 1500 hours of piano practice under his belt (also his father is the one who actually wrote down the composition...). Edison said genius is 99% perspiration and 1% inspiration. Steve Wozniak could work for four days straight without sleep. I don't deny that luck, intelligence and perspective are factors, but persistence always accompanies genius, and geniuses regularly cite it as their edge.
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it has been widely stated that if one was to read one hour each and every day for 5 years on one subject, he would become the worlds leading expert in that one subject.
i digress :)
back to the topic at hand
Guy:
i can conceptualize how forces from a 6/1 are transmitted thru to a particular point within the concrete block, at a specific rpm, at a specific torque output, at a specific degree of crankshaft rotation etc. theoretically we can calculate exactly where this point is within the block of concrete and in doing so determine the dimensions of the concrete block, i don't need to do the math to accept this as fact, but that is where we part ways.
where i part with you in doing the math, is the results cannot be linear, as the point within the block will move based on degree of the crankshaft, timing of combustion, torque output and other factors. this would necessitate a chain of calculations or more likely an educated guess as to something close enough for satisfactory operation.
there are literally dozens if not hundreds of variables, so there is no way there can be a difinitive answer or one right dimension, but rather something close enough to work over the intended range of the engine.
variables to be considered are as follows
engine hp as a variable, if a 6/1 needs a ton, then what about an 8/1 at 850 rpm or a 10/1 at 1000rpm? i am not aware of there being a different concrete base for different hp ratings or rpm. my only mention of hp is in a generic sense, in that there certainly higher stresses, vibrations etc in a 8 or 10/1 than a 6/1, it would appear that these stresses are not part of the equation, and neither is a difference in rpm
when i stated earlier that i can conceptualize the vectors, and the forces being transferred into the block, i meant that i can see it in one plane of thought, at one point in operation, beit degree, power output level etc. this is based on a single engine bolted directly to the ton of concrete
what becomes unclear and seems to lead me away from your arguement is when the same engine is mounted to a som cast iron base and then the assy bolted to a concrete base, the vector arguement does not hold, at least to the point that the forces are transferred to a point in the block
lets step away from a lister vertical to some other horizonal single of similar size and output, now the vectors are changed 90 degrees and there is no way that these forces are directed to a point within the concrete, but rather contained within the crankcase proper, wierd harmonics not withstanding.
the bottom line as i see it Guy, and i want to be careful to state this in a non inflammatory way, so please take this with sincerity
"it is your contention that lister engineered the concrete base to fit their engine" this is your statement of fact , theory, or position
it is therefore incumbent upon you to back up your statement with supporting facts that are directly related and pertinent to the position, further it is incumbent on you to produce your "work product", "supporting formulae", "references" etc. so that anyone conversant in math can come to support your assertion
it is not incumbent upon me or anyone else to either prove or disprove your assertion or position.
i would also like to note that if i was to make a statement that lister took a shortcut and did not design their intake manifold to optimize the VE, you would certainly call me to task, would you not? (yes you would and have)
it would then be incumbent on me to show some form of proof or at least some form of proof of concept, with related formulae, test results etc. i could and would provide copious amounts of information, documentation, formulae (that directly relates to manifold design), and with a bit of work some test results to back up the claim.
if i did not come up with anything concretely related to the assertion (such as formulae), you would rightly not accept my postion or assertion.
Guy i continue to press this issue not because of trying to prove or disprove either position, but rather to learn. what i learn often has broad application to other facets of what i do that often has no direct relation to the original problem.
respectfully
bob g
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Bob, when I want to be I can be a FUCKING good engineer, but I fall so far short of even lesser gods like henry ricardo and james watt and otto diesel and a string of other names whose boots I am not fit to lick it ain't even funny, and THEY worshipped people like newton and cavendish and maxwell etc.
Rudolf Diesel, not Otto, as I'm sure you know.
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I need to read this a little more later I just wanted to wish the best to Guy with regards to the baby on the way.
I had a hand in some clever engineering years ago and learned that my math skills suck.
I do recall some clever math relating to this sort of thing from college taught by a fat guy who used to work for NASA who mumbled and scribled and sweat at a chalk board and end every sentence with as you can see and very simple , a German woman who would scold me for looking in the back of the book and a Scottsman who could spend hours discussing " Nodular Iron " if you got him off topic...
What I have learned is Genius combines math with creativity. I walk on my knuckles and swing from the screen and ground support like a cave dwelling ape because. I don't use and lost most of my math skills, I replace rather than repair, I'm more interested in the technology of pre silicon era and shun what I don't like and last but not least I just am not paid to think and plan just do and react.....
Doug
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Doug:
" I replace rather than repair, I'm more interested in the technology of pre silicon era and shun what I don't like and last but not least I just am not paid to think and plan just do and react....."
i have been fighting this fight for the last 15 years of better, it has prevaded my profession to such a point that it is rare you can find anyone that can fix anything.
parts changers have taken the place of mechanics, but wait than seems derogatory so lets call them technicians. such bullshit.
i refuse to be known as a technician, i am a mechanic and strive to be a mechanic in the truest sense.
this is precisely why i question nearly everything these days, when it is presented to me that "its the way it is" or, "its the way its always been done" or " thats the way it was engineered" and having no documentation to back up the claim automatically raises red flags to me. (Guy, please take no offense here, i am using a different standard on our discussion)
in my profession we used to rebuild every component of a truck, everything! and if you were to be a good mechanic you learned how and became proficient at rebuilding every component on a truck from starters to alternators, waterpumps to injectors, cluches to differentials you name it.
today i would bet there are no more and likely far less than 1 in 10 so called technicians that could rebuild any single component let alone all of them.
don't get me started on diagnosis, that has become a joke.
complaint: truck won't start
a. replace batteries,, does it start now, no? go to b
b. replace starter, does it start now, no? go to c
c. replace ignition switch, does it start , no go to d
d. replace engine, does it start now, go to e
e. jack up radiator cap and drive under new truck, then go to f
f. replace radiator cap, does it start now? if not go to g
g. hide! take a sick day, leave it for someone else.
previous example is probably an over simplification, but you would be surprised just how close it is to reality.
another example, over the last few years i have had the misfortune of having to follow up dealers and other shops to work out issues with HUEI fuel systems on 3126 cat engines,
many times i have had phone calls, personal conferances, etc trying to get diagnostic procedures from the manufacture, with disastrous results.
each of the technicians at cat had been developing their own individual diagnostic procedures, because cat supposedly had not published procedures
about a month ago, in frustration i went out into the cat dealership shop, and asked to see their manuals, there on the top of the shelf was a complete diagnostic manual for a 3126e model, with diagnostic flow charts, spec's , procedures etc..... with at least a quarter inch of dust on it,
no one knew of its existance!
unbelievable!
ya technicians, parts changers, that is what they have become, sad thing was the lead guy was not even smart enough to use the book, look up anything in the book or even figure out where the index or contents pages were!
yup drop a couple of nukes and get some EMP, and down goes every single one of these engines, and no one will have a clue how to fix em
except for ordering all new electronics and replaceing everything, which should take about a year, because the delivery trucks won't run to deliver the parts anyway
i would suggest anyone that is at least a little handy with tools, mechanically inclined, do a bunch of independant study, learn how to fix it yourself.
and those of us that are in the fix it business, better slow down and take a good look where we have come from and where we are being dragged.
bob g
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One day many years ago for a breif window of time my hands were made of gold....
No joke everthing I touched worked....
I could "feel" the difference between a C3 clearence and bad shaft/bearing housing fit. I could tell by touch and smell, texture and yes paper pad and calculator what would work and what was trouble. Those were happy times, but I was also so poor I had to take the bus to work and often I walked becuase I had no bus money.
Now I make good money and I don't have the golden hands or the desire. Mother INCO beat it out of me, that kind of work is beyond the scope of a man who is expected to drop from the sky with a beat bag, chant burn some insence and make crap work. I doesn't matter what you do to make the crap work as long as it works....
A machine that cost 2 million bucks but does 25 million worth of work in a a week can be held together with snott, the string from used harpons, wishful thinking, ritual, therapudic massage, and tender romatic moments with a dead blow sledge hammer and no one cares as long as it keeps running....
I hate the fact I seem to be the only guy left that understands a U-215 frame motor and a T-215 are not the same and one has the potential to snap shafts and will trip overloads run hotter make more noise ect...
" DC BUS OVER VOLT "
I know that this means you clowns in general engineering, you had your chance to listen too me but no. Your smarter than me and better educated than me. I can fix this but your too proud to ask....
I'm realy tired of fighting, so I don't any more. I think you said once your in Oregon.....
There is an electric motor in the wheel of a Boewing nose wheel under test that has a little ME in it and my contribution netted me enough stock to buy a pack of smokes.
The world is messed up beause it doesn't pay to fix things and be creative anymore. Infact your making trouble if you rock the boat.
Doug
BTW I like engineers, the smart kind who know math and listen to other peoples ideas.
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Doug:
i can certainly relate to your plight
i have somehow mutated to being the last guy in the area it seems to call when all else has been tried and failed, usually miserably
today started at 6 am and i just got home at 10:30 pm
interesting day
2 days ago, one of my customers called with a hyd leak on a new (5 days old) drywall boom truck, got there and found a hyd swivel had lost its little
pin that retains the balls, and all the balls fell out, waaalaaa big leak, oil all over a million dollar home driveway, and somehow according to the homeowner it was
my fault! hey crap happens and stuff fails sometimes for no apparent reason. got the thing reattached and the truck off site. oh yes raining like hell and absolutely a
horrific access problem to boot.
last night i went out with a new american made steel swivel with an actual screw to retain the balls unlike the little rivet the italians seem to like, hooked it up and all is well
today bright and early another call, swivel broke!
got to the site and there was 6 inches of standing water over a foot of mud and i have to crawl under to inspect and repair, only to find out it is another of the five swivels that had lost a rivet and balls,
removed and replaced all five swivels with american units, found that another had lost its rivet and the last one was leaking badly... shit!
4 hours to change them,,
called the manufacture, talked to engineering, and they stated "oh yes we have had a few problems" we sent the customer new updated swivels, checked them out and found them to be the same swivels, same part number and date code!!!! ya right..
i explained that the way they mounted them in the mast allowed them to hammer together as the hyd functions are activated and this likely was the cause of the rivets coming out..
their assinine responce "who are you to tell us what the problem is, you are just a mechanic"
"well f@#$ u too buddy!" was my responce.
my job has morphed into one of fixing other engineers screw ups, and it has become a daily routine on all sorts of equipment, and i am sick and tired of it.
i am sure there are very fine folks that do engineering, i just don't happen to get to meet many of them anymore.
the rest of the day went much the same,
next call, "bob, help, we cant get this allen head bolt out so we drilled it and broke off an easy out in it" broke off down in the socket head where the allen wrench has to fit, and the head is recessed in the part to where you can't get at it with anything else. no don't call me when you first encounter a problem, screw it up good first!
then stand over me and apply stress to me that you have to have it fixed yesterday...
oh ya.... bring it on
some peoples children!!
yup gone are the days of being able to just go out and repair stuff, overhaul worn equipment, the kind of thing you can feel good about.
today it is just get it going as fast as you can, and don't charge me for it, or if you are going to charge me, not too much...
no wonder the old guys i remember as a kid were so grouchy,
omg, i am an old guy now, i guess it is my turn to get grouchy
bob g
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it has been widely stated that if one was to read one hour each and every day for 5 years on one subject, he would become the worlds leading expert in that one subject.
i digress :)
back to the topic at hand
Guy:
i can conceptualize how forces from a 6/1 are transmitted thru to a particular point within the concrete block, at a specific rpm, at a specific torque output, at a specific degree of crankshaft rotation etc. theoretically we can calculate exactly where this point is within the block of concrete and in doing so determine the dimensions of the concrete block, i don't need to do the math to accept this as fact, but that is where we part ways.
where i part with you in doing the math, is the results cannot be linear, as the point within the block will move based on degree of the crankshaft, timing of combustion, torque output and other factors. this would necessitate a chain of calculations or more likely an educated guess as to something close enough for satisfactory operation.
This is why you need to do the math.
If you take the moon example you will see it doesn't have a position (apart from an instantaneous one) but rather it can be found somewhere along a track, and the track is what you calculate.
You're right about the lister, there is no point, x y z co-ordinate defined, there is an area, this is why you need the math.
Have I mentioned you need the math? Good, cos you need the math.
Nobody likes the math, because it involves differentiation, dt over dy and all that stuff, and it is a real obstacle on the road of learning, I can still remember sitting in class looking at the board and being utterly lost and wondering what the fuck the teacher was on about, but it is the engineering equivalent of the micrometer, until you make it an everyday tool you flat out will not be doing any precision work to spec, the math is the same, until you master it you flat out will not be getting useful answers.
I don't like the math either, and nowadays I use it so infrequently I have to re-learn it, but I have learned it, I have used it, and I have used it (in collaboration with others) on a CS, and lister had it right.
the cast iron base doesn't magically change anything, it makes a difference that you factor into the math, it alters the end results but does not turn them on their heads.
=======================
here is a thought problem for you.
dissect it and tell me where it is wrong
Lister CS 6/1 is rated at about 47 ft/lb of torque
4.5 inch bore, 5.5 inch stroke.
5.5 inch stroke = crank radius of 2.25 inches
47 ft/lb = 564 inch/pounds
564 inch pounds / 2.25 crank radius = 250 lbs force on crank at 90 degrees after tdc firing stroke
4.5 inch bore = 2.25 inch bore radius
3.14 x (2.25 squared ) = 15.89 square inches piston area
250 lbs force / 15.89 inches piston area = 15.73 psi, just over 1 bar.
And yet 19:1 compression ratio (valve in) and 17:1 valve out gives us 19 x 14.7 = 279 psi, and 17 x 14.7 = 250 psi
If we assume 250 psi cylinder pressure at 90 degrees past TDC firing stroke we have 250 psi x 15.89 square inches piston area = 3970 off pounds force on the piston, 3970 pounds force at 2.25 inches crank radius = 8900 odd pound inches, /12 for 740 odd foot pounds.
So we calculate torque is 750 odd foot pounds, and yet we know torque is a shade under 50 foot pounds.
a/ tell me where the mistake(s) are in the above, and what they are.
b/ tell me how you get 47 ft/lb out of the correct equations. (don't evade the question by saying from a dyno, you can't dyno a blueprint and that is the stage where these things are calculated so you know if the design is viable)
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Guy:
unless i am missing something, (likely) the flaw in your calculations is very basic
"If we assume 250 psi cylinder pressure at 90 degrees past TDC firing stroke "
your answer is based on an assumption? perhaps the flaw is not in the math, but in the assumption
also rated engine torque is something that is arrived at, at a constant rpm, without undue strain or temperature rise, undue smoking or other detrimental effect. rated torque is an average figure and not an instantaneous figure derived from a simple formulae based on on degree crank angle.
getting back to the point here
you insist that lister got it right by spec'ing out a yard of concrete or was it a ton of concrete, you further insist that they arrived at this spec thru careful engineering
if remember correctly you state that lister made only one recommendation and that was the ton of concrete. have i fairly restated your position?
if i remember correctly you have stated that they made no other recommendation as to spec for a concrete base
could you tell me what the fundamental difference between a 5/1 and a 6/1 as it relates only to the concrete base?
i dont have all the spec's/dimensions on a 6/1 but i do a 5/1, so would you consider them to be virtually the same engine, for purposes of determineing the proper concrete block, size, weight and dimension?
or can i calculate base on the 5/1 spec's to figure the concrete base to mount a 6/1 onto?
it is my understanding that both engines are basically the same, physically, i would assume there to be a slight difference in bore perhaps, or slight increase in rpm for a 6/1
but all else is virtually the same.
i think i am getting closer to an understanding, but could use your continued input
bob g
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Math is good, having some other person do the math for you correctly is better...
Thanks Guy for your input, and I'll spare you the engineering jokes I toss at people.
Doug
Bob....
I just don't care much anymore. That translates to just about time to hang up the beat bag and start pulling cable. Unless of course something cool comes up lol.
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Guy:
unless i am missing something, (likely) the flaw in your calculations is very basic
"If we assume 250 psi cylinder pressure at 90 degrees past TDC firing stroke "
your answer is based on an assumption? perhaps the flaw is not in the math, but in the assumption
It was an assumption, but a fairly good one.
see http://www.kyma.no/sitefiles/site59/files/files/KDAreport.PDF 4 page pdf, some nice interesting data there.
then you need to do some of that math stuff to plot bearing load and torque at each degree of rotation, which will give you a bunch of other interesting answers.
few of which correlate with the dreaded "common sense"
also rated engine torque is something that is arrived at, at a constant rpm, without undue strain or temperature rise, undue smoking or other detrimental effect. rated torque is an average figure and not an instantaneous figure derived from a simple formulae based on on degree crank angle.
so your response is torque is not instantaneous, but the average figure over 720 crank degrees of the 4 stroke cycle.
good answer, it would require vastly higher instanataneous torque between TDC and TDC + 90 degrees, lower mechanical advantage of just past TDC compensated for by vastly higher cylinder pressures, as crank turns and mechanical advantage increases, cylinder pressure is dropping, so peak cylinder pressure is going to rise from 17:1 or 250 psi at injection to whatever the design peak is at around TDC firing stroke + 15/20 degrees, which will coincide with peak torque wear piston/barrel and big end / journal
getting back to the point here
oh, we never left the point.....
If you have peaks of maybe 1000 ft/lbs acting inside your engine you damn well need to know, because this directly affects where the centre of effort of these forces is going to be located.
you insist that lister got it right by spec'ing out a yard of concrete or was it a ton of concrete, you further insist that they arrived at this spec thru careful engineering
if remember correctly you state that lister made only one recommendation and that was the ton of concrete. have i fairly restated your position?
if i remember correctly you have stated that they made no other recommendation as to spec for a concrete base
could you tell me what the fundamental difference between a 5/1 and a 6/1 as it relates only to the concrete base?
[/quote}
A 6/1 is just a 5/1 running faster.
Each individual power stroke isn't generating any different loads, they are just happening faster, higher frequency, shorter wavelength, same amplitude.
the concrete block is about amplitude, not frequency per se, it keeps coming back to that math.
i dont have all the spec's/dimensions on a 6/1 but i do a 5/1, so would you consider them to be virtually the same engine, for purposes of determineing the proper concrete block, size, weight and dimension?
they are the same engine, apart from the frequency issue mentioned above.
or can i calculate base on the 5/1 spec's to figure the concrete base to mount a 6/1 onto?
it is my understanding that both engines are basically the same, physically, i would assume there to be a slight difference in bore perhaps, or slight increase in rpm for a 6/1
but all else is virtually the same.
6/1 is a 5/1 running at 650 rpm instead of 600 rpm
i think i am getting closer to an understanding, but could use your continued input
bob g
you gotta do the math.
you did not tell me what was wrong with my "question" and then tell me the right answer.
you hinted at it, but you didn't answer directly and lay it on the line
go work out the answer and ideally the reasoning in some detail and lay it out here, it will solve much of the question you keep asking.
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everyone thinks 650 rpm = 650 rpm = 650 rpm
nope, it is a MEAN speed.
why else do your lights flicker?
you think your lights visibly flicker because the engine went from 650 rpm to 649 and back up to 650 again? a change of 0.15%???
get real, there are two full rotations in a 4 stroke, you only get (useful) power on one quarter of one rotation, the other one and three quarter rotations are drag, in varying amounts, the last compression stroke being the worst.
measure rotational speed degree by degree for each of those 720 degrees of rotation and you see some remarkable changes.
5% is nothing to talk about, 10% isn't even exceptional.
5% is 32 rpm, you think you can see it, you can't.
32 rpm acceleration in 90 degrees of crank travel.
with a 24 inch dia flywheel you have 75 inches of circumference, 32 extra rpm is 32 x 75 = 2400, 200 feet.
650 rpm is 10.83 revs per sec
1 rev is therefore 0.092 sec
90 degrees of crank rotation is a quarter of that, 0.092 / 4 = 0.023
200 extra feet of flywheel rim travel in 0.023 seconds, is 8695 feet per second
say you have 100 lbs of iron in each rim, 2 flywheels, 200 lbs of iron being accelerated an extra 200 feet in one fortieth of a second.
whats the tensile / shear / compression numbers of cast iron?
Why is the apparently incredibly conservative 60 mph rim speed always used?
what do you think actually causes the stress failures in flywheels that allow them to explode in overspeed conditions?
You weren't going to destructively test your flywheel on a smooth electric motor and then take those number as being good for a single cylinder engine were you?
why were early cast flywheels made with s shaped spokes?
what happens to torque output if you double flywheel mass, or halve it?
work the math
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The answere is 42..... It was a tough assignment.
My Petter calls for a yard a well. I just assume this is a carry over from the Listerany thoughts guy?
Doug
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well it comes down to me taking a stand and calling bullshit!
it has taken use many months of back and forth on this subject, then yesterday i was sent the recommendations and specifications for a 5/1 lister, the contributor sent me an copy of an original lister document for a 5/1
the problem is a difference in dimension of the block of concrete
the difference is so vast in what the recommendation from lister for a 5/1 and what you report for a 6/1 that it simply cannot be explained by any mathematical calculation
you reported on many occasions that lister spec'd a specific dimension of approx one yard of concrete, for a 6/1, and doing some quick math in my head is approx 2500#s give or take.
if there was some higher order engineering that took place there would be no possible explanation for lister to have recommended a base of ~600# lbs for the 5/1
unless you are prepared to take the position that the extra 50 rpm necessitated the need for another 2000 lbs of concrete?
if you wanna go there, i can't wait to see the non linear equation to arrive at anything less than a 10,000 # concrete block for a 8/1 running at 850 rpm
the only possible explanation basically comes down to this
a well balanced engine does not need a heavy base of concrete as evidenced by lister and the 5/1, a less than well balanced engine needs a larger block of concrete as evidenced by the 6/1
a dollar to a dog turd says there simply was no high level engineering that went into the design of the concrete base.
this has been an interesting exchange of the theoretical, too bad we could not have arrived at the actual formulae or calculations for determining the dimensions of a concrete base.
obviously none existed or were applied at the time.
check
bob g
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ps:
if you would like i can forward the lister print for a 5/1, which has clear dimensions of a block of around 600lbs
i dont know how to post the link of a pic, but i can forward the email attachment
bob g
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I won't pretend to say I understand everything about mass dampening or moving the center of force blah blah.
But I can see in my minds eye some static force vectors as aplied to a crank. Is it then reasonable to assume that the addition of mass at the other end of the crank case will shift forces on crank, to me yes.
So where can I find "Rotational forces on cranks shafts and mass dampening of their effects for Dummies" to read up on this?
No way any engine with a litre of displacement will ever be so well ballanced that a good foundation or at least some dead weight isn't needed so how much do I need for a Petter?
Is more than a yard better?
Is just enough to keep it from hopping enough?
The force wasted making a block move is in fact wasted work. So how does one come to terms with all this information ?
Doug
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Guy:
please take note of the specification print for the 5/1
http://www.oldengine.org/members/diesel/Technical/51P3data.htm
maybe a quarter yard of concrete? you do the math
then read the final paragraph related to mounting here
http://www.oldengine.org/members/diesel/Technical/51P4data.htm
"INSTALLATION:
particulars of engine mounting and type of drive should be stated wherever possible"
clearly the point being made is that the mounting method is anticapated to be determined by the end user, and lister would like to know about it if possible
the light is fading on this one, rather quickly, how can you continue to support the assertion that the concrete block was an engineered part of the engine, or had any basis in the original design?
i have asked for a formula, doesnt even have to be from lister, and to date no one has come up with one.
i think it is apparent that i (with a bunch of help from an unnamed individual) have disproven your assertion, which was not incumbent on me to do.
now i want the formula!!!
enough with do the math!
i wanna see the damn formula
checkmate
bob g
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Hi I'll bet the conversation in Dursley went like this
Sales dept
"We need to sell engines to some country people at a set price."
Engineer
"Set it on a block of concrete. This is a stationary engine and concrete is cheap!" " Besides the trade has always done it this way!"
Legal dept.
"We don't want claims from customers, make the block of concrete bigger. We are'nt paying for that."
;D
Dennis
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DKW:
Hi I'll bet the conversation in Dursley went like this
Sales dept
"We need to sell engines to some country people at a set price."
Engineer
"Set it on a block of concrete. This is a stationary engine and concrete is cheap!" " Besides the trade has always done it this way!"
Legal dept.
"We don't want claims from customers, make the block of concrete bigger. We are'nt paying for that."
So you're a bit cynical too eh? :D I'm sure that you are much closer to the truth than some others.I'm equally sure that when the concrete block was first "designed in" around 1907, the people at dursley couldn't even spell calculus. ;D .
Makes for good entertainment value though don't it? Does anyone remember the monty python sketch where (I think) Terry Jones walks in and says "is this the right room for an argument?" Apologies to all non python fans, you are sadly lacking in your education ;)
Cheers,
Brian
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A: Come in.
M: Ah, Is this the right room for an argument?
A: I told you once.
M: No you haven't.
A: Yes I have.
M: When?
A: Just now.
M: No you didn't.
A: Yes I did.
M: You didn't
A: I did!
M: You didn't!
A: I'm telling you I did!
M: You did not!!
-
i have been working on a reconciliation of the information and developing another theory, which at this point i feel holds as much water than any other theory
and likely far more than some of late.
in the beginning lister built a 3/1 and as fine engineers, the refined it very well, balanced it to a gnats ass of being perfect, and it was good.
they then took it apart and carefully weighed and measured every last part, and then set out to replicate parts to these spec's , and all was good.
having built all these parts, they set to assembling there engines, and then came a revelation,, some of the engines were excellent, (they would run sitting on a pallet), some more of them were very good (needing to be bolted down to timbers) , and the rest were good (but needing to be bolted to approx 600lbs of concrete)
, and all was still good because folks bolted stationary engines to concrete anyway.
what lister in effect had was A grade, B grade and C grade engines, all of which would run excellent on a concrete base. and all was good.
when a customer ordered an engine, lister wanted to know how the engine was to be mounted, simply to be able to select the grade of engine that best suited the end use, they didnt have to tell the customer they just did it. if Joe needed a pump motor to run down at the lake to pump water to his field , he got a C grade motor.
if George needed a motor to run in his generator shed that was out in the barn he got a B grade motor, if John needed a motor to run in the generator shed attached to his house, he got an A grade motor. and all was good. everyone was happy
as years went by, and the cost of manufacture began to rise, along with lister getting into other more profitable engine products, the bean counters began to look to where they could cut costs of manufacture of the 6/1. experience told lister that engines will run literally forever, bolted to concrete, and careful balanceing of parts, sub assemblies etc cost extra money in manhours, so it was decided to see if an engine not so finely balanced could be made to run well and what size of concrete block would be needed to mount it. gone were the days of "tell us how you are going to mount it" and all was not so good, but folks bought them anyway on the premise that the concrete block was an intregal part of the design (clever marketing, turning a negative into a positive) lister continued to sell engine's , they ran well and all was for practical purposes .. good.
moral of the story, there was no higher math envolved above simple accounting arithmatic when it came to the design of the concrete base, further, if you have an engine that you are trying to make to be as good as it can be then have it professionally balanced after which it will probably run forever bolted to a pallet. if you dont do that and have an engine that is built up of poorly balanced parts then you will have to bolt it to a ton of concrete, and likely it will be shorter lived.
bob g
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please take note of the specification print for the 5/1
http://www.oldengine.org/members/diesel/Technical/51P3data.htm
maybe a quarter yard of concrete? you do the math
then read the final paragraph related to mounting here
http://www.oldengine.org/members/diesel/Technical/51P4data.htm
"INSTALLATION:
particulars of engine mounting and type of drive should be stated wherever possible"
clearly the point being made is that the mounting method is anticapated to be determined by the end user, and lister would like to know about it if possible
Bob, I believe the concrete block has become your Moby Dick.
Your argument has two parts. First is, I believe, "speced block size tripled between the 5/1 and 6/1, and this drastic change cannot explained by a mathematical formula, therefore the block is not an integral part of the engine design." That simply isn't true. No doubt their formula involved safety factors and machining tolerances. Changing either of these variables could account for the discrepancy. Or it could simply be a mandate from the legal department. I think we're in agreement about this latter part.
"Particulars of engine mounting" must refer to such things as indoor/outdoor and soil type. The reason I'm confident about this is that the specs you referenced belie your point: the engine blueprint shows the concrete block as part of the dimensions of the engine. There isn't the least bit of wiggle room about this, it could not be more stark. You're exercizing willful disbelief.
the light is fading on this one, rather quickly, how can you continue to support the assertion that the concrete block was an engineered part of the engine, or had any basis in the original design?
i have asked for a formula, doesnt even have to be from lister, and to date no one has come up with one.
i think it is apparent that i (with a bunch of help from an unnamed individual) have disproven your assertion, which was not incumbent on me to do.
now i want the formula!!!
enough with do the math!
i wanna see the damn formula
checkmate
Awhile ago you stated something to the effect that all aspects of IC engines are determinable via well-known formulas. I think you will agree that when someone develops a revolutionary piston profile, no one is impressed until they see the dyno numbers, despite whatever the math might say.
Mathematical models are just that, models. Celestial models improved with Newton then again with Kepler and then again with Einstein, and they aren't perfect yet.
None of us knows how sophisticated and accurate was the math that RA Lister used. It could have been on the back of an envelope, or it could have been exemplary. It doesn't matter, because we have seen the results. This being the case, it is in fact incumbent on you to prove that the block was a suggestion, not part of the design.
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Pro:
you cannot have it both ways either!
if one cannot determine the outcome of aspects of an engine design such as valve timeing, bore stroke ratio, VE etc, then you damn sure cannot determine anything about a concrete block.
and you are missing the point entirely
it has been asserted that lister only specified the use of a ton of concrete, or a yard whichever it was. it was reported that the yard/ton of concrete was an intergal part of the engine design.
clearly they provide specifications for both 600 lbs and your ton of concrete, this cannot be mathematically explained with any provable formula, not ever!
further you miss the mark in that i am not an opponent of the use of concrete, beit 600 #'s or a ton, i simply was looking to find the actual equation, and to date no one includeing yourself has come forward with such formulae, or any reference to lister having used said formulae.
quite frankly i don't give a crap what anyone mounts their engine to.
what i do care about is being told to do the math, and not having any proof of an equation ever being used or any reference to an equation.
also i would like to note, that words have meaning, specific meaning
when lister requested the particulars of engine mounting they did not ask for the particulars of engine installation
"mounting" does not equal "installation"
mounting referrs to what the engine is bolted to, and
installation takes into account the soil type, building type and myriad other concerns
as for you explanation of the difference in 600#s and a ton, being because of altering the spec's of the engine, please how does your accessment carry more
water than mine?
the only spec that could account for the large difference in block weight would have to be one of quality of balance, no other spec would result in the need for that much more concrete.
as for it being a result of being safety concious, here again i take exection, do you have any supporting evidence that the earlier recommendation of 600#'s of concrete being insufficient and causeing property or bodily damage?? i seriously doubt it.
obviously many of you have never worked with a very well balanced machine/engine, one that is properly tuned and set up will run quite nicely sitting flat on the floor.
such an engine is quite a marvel to behold and i have no doubt that the early listers were of this quality.
further i would assert that the A grade engines in later years became the engine of choice for the SOM's
seriously it only makes sense,
there are those on this board that look to lister as if it was designed, machined, assembled by arch angels, and ordained by God. it is not!
it is simply a good engine, and in some cases an excellent engine built by men, ordinary men, that were craftsman to be sure, but ordinary men that ate, slept and shit just
like each one of us.
i tire very easily when there are those that put lister on some pedestal that is beyond question, one should be able to ask any question of any man or company, and get a clear and concise answer, not some crap about "just do the math"
and finally,
i have no doubt that i could build a 6/1 from one of the kits, carefully balancing it either myself or hire it done, detail it properly and have an engine that would run as long as any other listeroid and have it mounted to timbers, 600#s of concrete or even resilient mounted.
i have no more to say on this subject until "someone produces the friggin formulae", anyone supporting the use of concrete as being gospel from god is just full of shit.
bob g
-
you cannot have it both ways either!
What am I trying to have both ways?
if one cannot determine the outcome of aspects of an engine design such as valve timeing, bore stroke ratio, VE etc, then you damn sure cannot determine anything about a concrete block.
But you can't exactly predict the effects of many engine design decisions. That's what dynos are for.
This is the nature of mathematical forumulas; the more work you put into them, the better the results you are liable to get. But they're never perfect on anything of any complexity, and thus we perform experiments. The fianancial "rule of 72" is a mathematical model, and it is useful so long as you don't expect too much from it.
But all this is beside the point. It doesn't matter how RA LIster came up with their spec, it's still the spec.
and you are missing the point entirely
it has been asserted that lister only specified the use of a ton of concrete, or a yard whichever it was. it was reported that the yard/ton of concrete was an intergal part of the engine design.
Apparently that's wrong, Lister specified the 600# (as you calculated) in at least one place. This doesn't mean that the block isn't part of the spec.
clearly they provide specifications for both 600 lbs and your ton of concrete, this cannot be mathematically explained with any provable formula, not ever!
How can you say this if you don't know what formula they used? They could have plugged in a different mean time to failure for instance, for whatever reason. If they did in fact use such a formula, they apparently changed a parameter between the 5/1 and 6/1.
But maybe they didn't use a formula at all, maybe the field agents said too many engines were failing in manner X, so they simply increased the block spec. Whatever the case, the block is still part of the spec.
further you miss the mark in that i am not an opponent of the use of concrete, beit 600 #'s or a ton, i simply was looking to find the actual equation, and to date no one includeing yourself has come forward with such formulae, or any reference to lister having used said formulae.
Sorry, no equation here.
quite frankly i don't give a crap what anyone mounts their engine to.
what i do care about is being told to do the math, and not having any proof of an equation ever being used or any reference to an equation.
also i would like to note, that words have meaning, specific meaning
when lister requested the particulars of engine mounting they did not ask for the particulars of engine installation
"mounting" does not equal "installation"
mounting referrs to what the engine is bolted to, and
installation takes into account the soil type, building type and myriad other concerns
I grant this is confusing. However, as with all Lister specs, the one you referenced shows the block as part of the dimensions of the engine. It's not a suggestion, it's the spec. So it makes more sense to reconcile the "particulars of mounting" to it, and not vice versa.
as for you explanation of the difference in 600#s and a ton, being because of altering the spec's of the engine, please how does your accessment carry more water than mine?
You say that a change in the block spec implies that the block is not part of the design. I just don't see it.
the only spec that could account for the large difference in block weight would have to be one of quality of balance, no other spec would result in the need for that much more concrete.
Maybe they did reduce quality of balance. What does this prove though?
as for it being a result of being safety concious, here again i take exection, do you have any supporting evidence that the earlier recommendation of 600#'s of concrete being insufficient and causeing property or bodily damage?? i seriously doubt it.
No, I don't. I don't know or really care why they made the change.
obviously many of you have never worked with a very well balanced machine/engine, one that is properly tuned and set up will run quite nicely sitting flat on the floor.
such an engine is quite a marvel to behold and i have no doubt that the early listers were of this quality.
further i would assert that the A grade engines in later years became the engine of choice for the SOM's
seriously it only makes sense,
I wouldn't know. I'm not making an assertion about this one way or the other.
As an aside, maybe you can explain something to me: is it possible to balance a four-stroke one-cylinder precisely? In my mind's eye I can't see how it could be smooth at idle and also during the power stroke at full HP.
there are those on this board that look to lister as if it was designed, machined, assembled by arch angels, and ordained by God. it is not!
it is simply a good engine, and in some cases an excellent engine built by men, ordinary men, that were craftsman to be sure, but ordinary men that ate, slept and shit just
like each one of us.
i tire very easily when there are those that put lister on some pedestal that is beyond question, one should be able to ask any question of any man or company, and get a clear and concise answer,
All I'm saying that RA Lister specified a concrete block, and thus it is part of the engine design. You don't seem to dispute that all CS specs feature the block, yet you are certain that RA Lister didn't really specify it.
not some crap about "just do the math"
and finally,
i have no doubt that i could build a 6/1 from one of the kits, carefully balancing it either myself or hire it done, detail it properly and have an engine that would run as long as any other listeroid and have it mounted to timbers, 600#s of concrete or even resilient mounted.
i have no more to say on this subject until "someone produces the friggin formulae", anyone supporting the use of concrete as being gospel from god is just full of shit.
bob g
As for 'do the math', you're talking to the wrong person.
The spec says use a concrete block, and you don't deny it. Yet, you say I'm full of shit for reading the spec literally. You, on the other hand, have provided an assortment of reasons for why the spec doesn't actually say what it says. Not only that, at least twice you've tried to shift the burden of proof onto me. I have to prove that Lister considered and rejected resilient mounts. I have to produce Lister's block size equations. If you doubt the spec, fine, so long as you accept the burden of proof.
-
Pro:
if you recall i started this thread in the attempt to get to the formula
you will derive from the references that were sent to me and posted at the beginning of this thread one thing and i another.
ten more guys can come in and derive maybe 10 other things, all of which makes no real difference to the question at hand.
we can debate the vargaries and the fineries of the lister prints, and sales text till the cows come home, i am up for it, but i doubt either of us will change the others mind
i posted those two links solely as proof that the assertion that the concrete block was an intergal part of the engine design is problematic.
i have also stated my reasons for seeking the formula and an understanding of the assertion that the block was intregal to the design of the engine, that is one of education and broad applicability beyond its use by me in mounting a listeroid.
without those two links the assertion of there being a formula for determing the spec on a concrete block still had some legs, some hope of getting there, but with them it is losing ground quickly.
again i will state "words have specific meanings" most especially when used in engineering, science, math or law. all of which are in play when applied to listers drawings and sales brochure. i have no doubt that they carefully chose their wording, and in doing so many folks will read what they want to hear into it. it just isnt there!
when they asked to be told about the particulars of mounting, they are not asking about particulars of installation.
mounting does not equal installation, these are two different words with two different meanings, most particulary when used in a machine context.
still waiting for the equation/formulae, dont even have to be for a lister!! give me a one for any machine to concrete
bob g
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Bob,
I think you neglected to mention that the 6/1, 5/1 and the 3/1 drawings all show the same size concrete block. If the dimensions of the block were the result of careful calculation, then a 3/1 turning appx half the torque of a 6/1 should have a smaller block. It doesn't. To me that indicates pragmatism, not calculation was used to spec. the block.
Quinn
-
Quinn:
thank you, it was an oversite
Pro:
"As an aside, maybe you can explain something to me: is it possible to balance a four-stroke one-cylinder precisely? In my mind's eye I can't see how it could be smooth at idle and also during the power stroke at full HP."
no i am not suggesting anything like that, just as i am not suggesting that you can balance a single cylinder engine perfectly, but you can attain a very acceptable level
of balance on either engine at a specific rpm. Because the lister/oid is likely to be running at a specific rpm this information can be relayed to the shop that dynamically balances your assy to be as well balanced as you are willing to pay for at this specific rpm.
no mass produced engine will ever be balanced as well as what you can do on an individual basis (generally speaking), and listeroids are no exception to this.
we have all heard of the listeroid that a guy bought and started on the crate and found it to sit there and chug away, and conversely we have all heard of the guy who started his on the pallet only to have it hop all over the shop and chase him out the door. cleary there is some issues related to quality of balance, bolting it to a ton of concrete won't make the hopper a better engine, it is just going to mask the problem.
as for having it both ways:
engine designers do not design engines on dyno's, they design them on paper, with calculations, math and established formula. with enought calculation and input data it is surprizing just how close the final dyno results are to the design. the dyno is used to further refine and and tune the engine and provide testing.
engine designers have had all the formula's to design on paper all manner of engines for the last 75+ years. even back then they were within a few percent of design on the dyno. today they can predict to very tight margins any change to an engine result in hp/torque/ fuel consumption etc.
and yes they could engineer a concrete block today, last week or 50 years ago, but funny thing is i can find no mention of any formula to arrive at an engineered solution.
either lister and ever other stationary manufacture had the formula and no it is lost to the sands of time or there was a simple rule of thumb approach used.
i guess like religion and politics, we all choose to believe what we want to
bob g
-
if you recall i started this thread in the attempt to get to the formula
you will derive from the references that were sent to me and posted at the beginning of this thread one thing and i another.
ten more guys can come in and derive maybe 10 other things, all of which makes no real difference to the question at hand.
we can debate the vargaries and the fineries of the lister prints, and sales text till the cows come home, i am up for it, but i doubt either of us will change the others mind
i posted those two links solely as proof that the assertion that the concrete block was an intergal part of the engine design is problematic.
i have also stated my reasons for seeking the formula and an understanding of the assertion that the block was intregal to the design of the engine, that is one of education and broad applicability beyond its use by me in mounting a listeroid.
without those two links the assertion of there being a formula for determing the spec on a concrete block still had some legs, some hope of getting there, but with them it is losing ground quickly.
I never said there was or was not a 'formula'. My remarks on the topic have to do with separate disagreements.
again i will state "words have specific meanings" most especially when used in engineering, science, math or law. all of which are in play when applied to listers drawings and sales brochure. i have no doubt that they carefully chose their wording, and in doing so many folks will read what they want to hear into it. it just isnt there!
Well, they also depict the block as part of the blueprint of the engine. I admit I'm confused by the 'particulars of mounting' statement, I don't exactly know how to reconcile it with the schematic. The schematic is certainly more straightfoward. The 'particulars of mounting' is listed under a section called 'Choosing an engine', so perhaps that explains it.
still waiting for the equation/formulae, dont even have to be for a lister!! give me a one for any machine to concrete
As I said before, no, I don't have a formula, nor have I looked for one. What do you think you are proving? I really don't understand. I think the block is part of the design regardless of whether to use a formula to size it.
You didn't address one part of my post: does the fact that the block size changed prove that the block is not part of the engine design? Yes or no?
-
"As an aside, maybe you can explain something to me: is it possible to balance a four-stroke one-cylinder precisely? In my mind's eye I can't see how it could be smooth at idle and also during the power stroke at full HP."
no i am not suggesting anything like that, just as i am not suggesting that you can balance a single cylinder engine perfectly, but you can attain a very acceptable level
of balance on either engine at a specific rpm. Because the lister/oid is likely to be running at a specific rpm this information can be relayed to the shop that dynamically balances your assy to be as well balanced as you are willing to pay for at this specific rpm.
no mass produced engine will ever be balanced as well as what you can do on an individual basis (generally speaking), and listeroids are no exception to this.
we have all heard of the listeroid that a guy bought and started on the crate and found it to sit there and chug away, and conversely we have all heard of the guy who started his on the pallet only to have it hop all over the shop and chase him out the door. cleary there is some issues related to quality of balance, bolting it to a ton of concrete won't make the hopper a better engine, it is just going to mask the problem.
I was just asking Bob, you would know better than I. But I don't think you answered my question. I'm not talking about balance differences between different RPM's. I'm wondering whether balance changes under different loads. Does it?
as for having it both ways:
Despite what you say below, I still don't know what you figure I'm trying to have both ways.
engine designers do not design engines on dyno's, they design them on paper, with calculations, math and established formula. with enought calculation and input data it is surprizing just how close the final dyno results are to the design. the dyno is used to further refine and and tune the engine and provide testing.
Well sure you can predict anything with enough input data. But where does input data come from? Experimentation and measurement, which you are saying is relatively unimportant in engine design. If you accept the the 'just how close' is extraordinarily important then I agree. If that weren't so, then all quarter mile dragsters would use virtually the same engine, the optimal one for the application, whereas in reality there is lots of variation.
engine designers have had all the formula's to design on paper all manner of engines for the last 75+ years. even back then they were within a few percent of design on the dyno. today they can predict to very tight margins any change to an engine result in hp/torque/ fuel consumption etc.
and yes they could engineer a concrete block today, last week or 50 years ago, but funny thing is i can find no mention of any formula to arrive at an engineered solution.
either lister and ever other stationary manufacture had the formula and no it is lost to the sands of time or there was a simple rule of thumb approach used.
i guess like religion and politics, we all choose to believe what we want to
bob g
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Pro:
"You didn't address one part of my post: does the fact that the block size changed prove that the block is not part of the engine design? Yes or no?"
had the change in block dimensions been marginal, i would say "no" it would not prove the block to not be a part of the engine design.
but the block changed dimensions radically, so "yes" that would prove it was not part of the design of the engine.
further i can find no mention of any manufacture ever using the concrete base as an intregal part of an engine design.
the use of the concrete block as an intregal part of the design flies in the face of all that has been published on sound engine design and engineering (at least for purposes of moving a center of mass, center of gravity is another story)
proper engine design (and i have no reason to believe that the good folks at lister were incapable of proper design) dictates that all internal forces/stresses etc are to be contained and managed within the structure of the engine proper, eg. the crankcase.
the lister crankcase is typical of design and shows no sign of deficiency that would dictate that a concrete base would improve upon. further...
if by design the lister needed the concrete base to stablize, increase strength, move centers of mass etc. the print would have included an iron or steel bedplate that would have been grouted to the concrete providing a broader contact with the concrete rather than the relative point loading that would lead to abrasion at the mounting bolts over time. for there to be a tranfer of forces to the concrete this connection would have to be very solid and if abrasion occured the engine would exhibit catastrophic failure which has not proven to be the case.
listers overall design is very good, solid and time proven, and was based on popular design as far as basic structure and crankcase design are concerned. for the power density envolved it is hell for stout and has no need for outside strengthening from a concrete base.
from a standpoint of simple, cheap, stable and expedient clearly the concrete base is a good method of mounting, i got no problem with that or its use.
the bottom line here is not whether or not concrete is good, bad or indifferent, or if resilient is good, bad or indifferent.
i just want to see some formulae or reference to the claim that the block has to be, or was a part of the structural design of the engine to begin with.
still looking, still waiting, perhaps i will find it but like granny used to say "maybe so, but i kinda friggin doubt it"
the more i research the further i get from accepting that the yard of concrete is the only way to mount a lister/oid and have an engine that will live longer than if mounted in an alternative (and properly engineered) manner.
bob g
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Pro:
"Despite what you say below, I still don't know what you figure I'm trying to have both ways."
let me try again, sometimes i don't relate what i see in my head well.
one way
there is the assertion that some higher level math was or can be used to calculate the movement of the center of mass, to within the concrete block, and in doing so arrive at specific dimensions for the concrete block
the other way
there is the assertion that you cannot predict or engineer an engine through formula to arrive at what the engine's output , fuel consumption, VE etc. with any precision. we have to have a dyno
so one could reconcile the two ways by stating that:
we can run calculations and formula's to get close on engine design, and then have to refine on a dyno through empirical testing and observation, and
we can run some calculation/formulae (which has not surfaced yet) to arrive at a specific dimension for a concrete block, then through some empirical testing and observation refine that dimension... so...
how is it that one spec calls for 600 lbs of concrete and another reference calls for a ton or a yard (which is over a ton) of concrete? this is an enormous difference, either the formula is flawed or is non existant. we are talking about a 300 to 400% difference in spec's!
we can sit down and design an engine on paper, using established formula and be well within 10% and the pro's are well under 5% of expected parameters on the dyno. clearly the calc's/formula are pretty accurate in most cases.
so how do you reconcile this difference? i wish someone could step up and support it, with something solid, some reference or formula.
questions i got,,, don't need more questions, need some answers
" I'm not talking about balance differences between different RPM's. I'm wondering whether balance changes under different loads. Does it?"
engine loading will not effect overall balance, at least in any way that one can do anything about. what it will do is raise cylinder pressures and produce more stress within the structure of the engine, which is contained between the cylinder head and the crankcase main journal's.
as far as all 1/4 mile dragsters, the top fuel boys all use the same engine's, same displacements and much the same ancillary equipment, the drive ratio's, tire pressures, clutch settings and the drivers are about the only variables left.
what is amazing is that today engine designers can sit down behind a puter and input all the parameters into the program, run it all thru, then produce the thing and come out damn close to what the puter said to start with.
you can take 3 engines of the same bore/stroke ratio, same rod length ratio and the same VE, made by 3 different manufactures and end up within under 5% of margin on any measurement of power/ fuel efficiency torque or whatever.
they could do it 50 or 75 years ago just as well they just used pencils paper and slide rules instead of puters.
today a manufacture faced with the need for a new engine will go to the engineering department and tell them the basic parameters.
"we want an engine that is X long, x tall, x wide, weighing in at x, that produces x amount of hp, x torque, at this rpm range, and with a fuel consumption rate of x."
the engineers design it and they got to be damn close or someone loses their job.
once built can it be improved on, generally yes!
bob g
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Im bolting mine too a big block of concrete so i dont have to lend it to friends and nieghbours....
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Tugger:
probably the most compelling arguement i have heard yet for the use of a ton of concrete :)
bob g
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"You didn't address one part of my post: does the fact that the block size changed prove that the block is not part of the engine design? Yes or no?"
...
... the block changed dimensions radically, so "yes" that would prove it was not part of the design of the engine.
To me that is an extraordinary claim. An engineer could simply have decided, "That's not big enough!", and increased the spec without altering the fact that RA Lister designed the CS for use with a block. We'll just have to agree to disagree here.
further i can find no mention of any manufacture ever using the concrete base as an intregal part of an engine design.
the use of the concrete block as an intregal part of the design flies in the face of all that has been published on sound engine design and engineering (at least for purposes of moving a center of mass, center of gravity is another story)
From my admittedly small knowledge of such things, I flatly disagree. I've not seen any industrial stationary engines mounted on anything but concrete. Rtgii posted a bunch of pictures here:
http://listerengine.com/smf/index.php?topic=1033.msg13851#msg13851
conversely I know of zero industrial stationary engines mounted on anything else.
proper engine design (and i have no reason to believe that the good folks at lister were incapable of proper design) dictates that all internal forces/stresses etc are to be contained and managed within the structure of the engine proper, eg. the crankcase.
the lister crankcase is typical of design and shows no sign of deficiency that would dictate that a concrete base would improve upon. further...
Yet again, I flatly disagree, on the basis of what I said above and also because the concrete block is plainly a part of the schematics that I've seen.
if by design the lister needed the concrete base to stablize, increase strength, move centers of mass etc. the print would have included an iron or steel bedplate that would have been grouted to the concrete providing a broader contact with the concrete rather than the relative point loading that would lead to abrasion at the mounting bolts over time. for there to be a tranfer of forces to the concrete this connection would have to be very solid and if abrasion occured the engine would exhibit catastrophic failure which has not proven to be the case.
listers overall design is very good, solid and time proven, and was based on popular design as far as basic structure and crankcase design are concerned. for the power density envolved it is hell for stout and has no need for outside strengthening from a concrete base.
Same comments.
from a standpoint of simple, cheap, stable and expedient clearly the concrete base is a good method of mounting, i got no problem with that or its use.
the bottom line here is not whether or not concrete is good, bad or indifferent, or if resilient is good, bad or indifferent.
i just want to see some formulae or reference to the claim that the block has to be, or was a part of the structural design of the engine to begin with.
still looking, still waiting, perhaps i will find it but like granny used to say "maybe so, but i kinda friggin doubt it"
the more i research the further i get from accepting that the yard of concrete is the only way to mount a lister/oid and have an engine that will live longer than if mounted in an alternative (and properly engineered) manner.
bob g
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Pro:
"An engineer could simply have decided, "That's not big enough!", and increased the spec without altering the fact that RA Lister designed the CS for use with a block. We'll just have to agree to disagree here."
This whole thread was based on the premise that lister used a formula to determine the base dimension, now some engineer just decide it wasnt big enough?
based on what? his feelings? or the fact that the block was not big enough by a factor of 4? ... give me a break!
"From my admittedly small knowledge of such things, I flatly disagree. I've not seen any industrial stationary engines mounted on anything but concrete."
i know of none either, but this does not prove the existance of some higher mathematical formula, but rather should make you wonder why there is no reference to one forthcoming if one did exist!
"Yet again, I flatly disagree, on the basis of what I said above and also because the concrete block is plainly a part of the schematics that I've seen."
fine, then you explain mathematically the huge disparity in the 5/1 prints showing 600 lbs and the 6/1 showing the need for 2000+ lbs, given the fact that the 5/1 and the 6/1 are the same engine, and for that matter the same as the 3/1. show me the formula to reconcile the difference!
so far all you have done is regurgitate all the same stuff, you have not come up with any new or sound engineering answers, the fact that concrete has been used forever for the mounting of heavy stationary equipment does not necessarily mean that it is an intregal part of any design.
again i will state based on much research, that all of the internal stresses and vibrations of an engine are addressed and handled within proper crankcase design, lister engines are not atypical in design and show no signs of being deficient in such a way that a concrete base adds anything to their function other than a place to bolt it down to.
it is ok by me if you want to blindly accept whatever is said to you, and it is ok that we disagree on this topic, and i have no interest in changing yours or anyone elses mind.
what would be interesting though is for those that hold your side of the arguement to come up with something solid to support the claim that lister used a formula to arrive at the spec, and some proof that from an engineering standpoint the block was an intregal part of the design. for that matter any engine, by any manufacture, same criteria!
for now i am still waiting, still reading, still looking for proof.
to date, still nada, zip, zilch, just a bunch of restatement and shuffling, and kicking sand
bob g
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I'm a fence sitter in this discussion. To me it's all application. If it's ok for vibration to be transmitted to the surroundings then start mixing. If it's not, then you better think resiliant. I'm not known for following instructions and, if I think I've got a better way, I'll try it. Occasionally to my detriment, but not often. I think most DIYers are the same. And natural selection will take care of those who should not be experimenting.
But....that's not what I'm here to talk about
I have been chosen as a messenger from the 'other side'. R.A. visited me in my dreams last night (he's shorter than I thought) and told me to give Bob his "friggin" formula. So simple and elegant I'm surprised it wasn't discovered earlier.
LV = 908,000
MF
where: LV = Lister Vibrations
MF = Mass of Foundation(in grams)
I was hoping to ask him a couple questions about my 'roid' but he was replaced by a 19 yr old belly dancer with a tiger and a dwarf before i had the chance.
Gotta Run (and hide) Bill
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Bill:
your killing me! :)
i gotta tell ya, you have some strange dreams there buddy.
too damn funny
bob g
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"An engineer could simply have decided, "That's not big enough!", and increased the spec without altering the fact that RA Lister designed the CS for use with a block. We'll just have to agree to disagree here."
This whole thread was based on the premise that lister used a formula to determine the base dimension, now some engineer just decide it wasnt big enough?
based on what? his feelings? or the fact that the block was not big enough by a factor of 4? ... give me a break!
I never made any assertions about whether Lister used a formula. My point has always been that you can't infer from the change in block size that the block is not part of the spec. You stated baldly that your inference is in fact proof, but it simply isn't.
"From my admittedly small knowledge of such things, I flatly disagree. I've not seen any industrial stationary engines mounted on anything but concrete."
i know of none either, but this does not prove the existance of some higher mathematical formula, but rather should make you wonder why there is no reference to one forthcoming if one did exist!
To my knowledge no one is looking for such a formula. You are the one who wants it. I have nothing to prove by presenting this to you. RA Lister could change their block spec because of what they observed in the field, or because they changed a parameter in their formula or switched to a different formula. None of these would alter the fact that the block is part of the spec.
"Yet again, I flatly disagree, on the basis of what I said above and also because the concrete block is plainly a part of the schematics that I've seen."
fine, then you explain mathematically the huge disparity in the 5/1 prints showing 600 lbs and the 6/1 showing the need for 2000+ lbs, given the fact that the 5/1 and the 6/1 are the same engine, and for that matter the same as the 3/1. show me the formula to reconcile the difference!
As above, I just don't care what the formula is.
so far all you have done is regurgitate all the same stuff, you have not come up with any new or sound engineering answers, the fact that concrete has been used forever for the mounting of heavy stationary equipment does not necessarily mean that it is an intregal part of any design.
I'm not making any engineering arguments, Bob. All I've tried to convince you of is that Lister designed the CS to work with a concrete block. My reasoning, as you know, is not based on engineering knowledge, it's based in the schematic that RA Lister published, and the fact that all stationary engines seem to use concrete. IMO "the fact that concrete has been used forever for the mounting of heavy stationary equipment" most certainly does mean that concrete is part of the design.
again i will state based on much research, that all of the internal stresses and vibrations of an engine are addressed and handled within proper crankcase design, lister engines are not atypical in design and show no signs of being deficient in such a way that a concrete base adds anything to their function other than a place to bolt it down to.
I'm not dissing you Bob, but I haven't a clue about your research, so I'd be naive to attach this much weight.
it is ok by me if you want to blindly accept whatever is said to you, and it is ok that we disagree on this topic, and i have no interest in changing yours or anyone elses mind.
what would be interesting though is for those that hold your side of the arguement to come up with something solid to support the claim that lister used a formula to arrive at the spec, and some proof that from an engineering standpoint the block was an intregal part of the design. for that matter any engine, by any manufacture, same criteria!
for now i am still waiting, still reading, still looking for proof.
to date, still nada, zip, zilch, just a bunch of restatement and shuffling, and kicking sand
My side? Maybe you think I'm in cahoots with Fawkes and that's why you keep asking me for a formula? You'll have to ask him. I'm agnostic about whether there's a formula. I just don't care much about it. My position is that RA Lister could have changed the concrete spec for any reason: formula, formula parameter, business, caprice, idiocy, you name it, and the block would still be part of the spec. As I respect the engine, I respect the block spec. You can call this blind trust, but that seems harsh to me. We're all agreed on the merits of the engine design, so I have no qualms about accepting the merits of the mount designed along with the engine.
I'm not trying to prove to you what you seem to think I'm trying to prove. My argument is this and this alone:
1) the block is part of the spec
2) a change in block size does not imply that the block is not part of the spec
I'm baffled that you keep asking me for a formula, and believe you've scored points because I haven't produced it. I haven't lifted a finger trying to find this formula.
You say that concrete is a part of basically all stationary engine mounts, so IMO that means concrete is a part of the design. Maybe it's a difference in semantics.
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Pro:
for the record, i have the utmost respect for you and for everyother soul on this board.
while i may not agree with everyone with everything, i am also cognisant of the fact that not everyone is going to agree
with me on everything, and that is a good thing.
i am not pounding on you for a formula, i am however pounding on GuyF to produce the formula as he has been the one that has stated that there was only "one" specification from lister, which clearly is not the case.
i should also state that i have deep respect for GuyF, and as he has been a time served engineer i take a harder stance with him to provide proof.
as you have stated perhaps lister used a different formula or changed the formula from the 600 lb spec to the ton spec, and if so then there should be reference to not one formula but two. This would tend to lend credence to the fact that there was no formula by reason that both formula's seem to be lost to time, which i find a bit hard to accept.
i might also add that i too will likely mount a lister to concrete or some spec that fits my needs, as well as likely one that is mounted resiliently. in either case i will buck up and spend the bucks to get either engine balanced properly to start with.
Again i am not trying to beat you or anyone into submission, but i did start this thread asking for proof of the formula or proof of concept or any other reference to the use of a formula by lister or anyother stationary engine manufacture.
i would ask you to think of the benefit of having the "formula", with it one could put together his machine, beit a lister/generator, a lister/pump or whatever and then work out the formula to determine precisely what he needed to accomplish his ends with a measure of assurance that he is at least in the ballpark enough to have a successful installation, without having to overkill the project or worry that he hasn't done enough.
maybe i am just a wierd asshole that is fixated on details? but i have been around the block a few times and have learned that the devil truely is in the details.
i don't know about you or others, but i know me and my acheing back enough to know full well that i don't want to poor an ounce more concrete than is needed, or conversely an ounce less than what is needed and have to chop it out and do it over again.
btw,,, still waiting for a formula !
(sorry i couldn't help myself) :)
bob g
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Hi I certainly am no expert. In the old days when a hi speed engine might turn1-200rpm The builders would put the engines on something that could stand the weight. And the pull from a flatbelt drive.
Have you ever looked at a steam donkey engine mounted on a skid?
I have seen an oilfeild engine mounted on blockes of mortered stone.
Have you seen a side shaft engine with a seperate bearing support? Then you need to have a stabile mount or the engine would wear prematurely.
A faster engine (600-1000rpm) needs to have more mass to hold it down. Drive pull has to be compensated for too.
I really don't think there was a formula except for the school of hard knocks! Then the builder might say from experience 2x the weight of the engine or what ever works.
Modern engineering practice would call for a subsoil exploration bore to determine if the ground was stabile and how much structure it would provide. In soft marshy ground you increase the size of the concrete base to suport even static loads. What I mean by static loads is building etc. no movement or viberation.
Dennis
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and don't forget the environmental impact statement !
i really suspect there is a rule of thumb to arrive at sizing of a concrete base, or a range to work from based on historical or empirical results.
i could accept that,
bob g
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Dennis:
your assessment that the design of the concrete block having to not only support the engine but provide for side thrust for a flat belt drive makes good sense to me
and it reconciles quite nicely with the dimensions of the concrete block in the lister 5/1 drawings, and teh 3/1 drawings, in that the block in the drawing has room to mount the engine but no room to make provisions to mount anything else, so the assumption is the driven accessory being remotely mounted and belt driven would need a fairly substantial/heavy concrete base to keep the engine from creeping under belt tension.
seems plausible to me, also seems a likely explanation for a specific size and shape of the concrete block in the drawing.
from a practical standpoint that is easy to understand or conceptualize.
bob g
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Bob: shall I go home and get my fucking shine box then?
http://www.youtube.com/watch?v=W5S-H4uE0y0
I don't know if you've seen that movie, but there's another funny line: "Looks a little like somebody we know!"
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GuyF, Pro and others of the proformula camp:
Mr. Bill had a dream, and last night so did I
and it all came clear to me, there isnt a formula but there appears to be a geometric explanation to the spec's of the concrete block.
it appears to hold true for the 3/1, 5/1 and the 10/2
i need to see prints for the newer 6/1 etc where the spec changed to more concrete, to see if the same theory holds true, and then check it against other manufactures to see if it holds up.
can anyone post a similar link for the 6/1 and the 12/1?
bob g
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GuyF, Pro and others of the proformula camp:
I'll run home and fetch that shine box now, Bob.
You are joking, right?
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Pro:
i am serious as a heart attack!
it was never my intention to deny any possibility of a formula. i just havent seen one
but i have a geometric answer that is plausible, and perhaps if it holds up with the prints of the later 6/1's and 12/2, (which i would not be surprised if it did) then i think i would have my answer, or at least an answer to the basic question.
don't get too excited yet, because from a geometric expression the block was not figured at the time of design or the engine, but as an afterthought or consequence of the designof the engine.
but of course feel free to disagree :)
if you don't i am sure someone will, hell tomorrow i may even disagree with myself!
bob g
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I'm not proformula! I don't have any position about whether Lister used a formula. I've sure tried to make that clear.
Actually, ever since the beginning of this discussion, if I had to bet I'd say Lister didn't use a formula, or at best a back-of-the-envelope one. I didn't bother mentioning this because I don't have any good reason to believe it. Nevertheless, that's where I'd put my money.
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Fair enough, point taken there Pro!
how's the view from up on the fence anyway?
hehehe
bob g
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Since the 3/1, 5/1 and 6/1 all share the same block dimensions, as I'm sure the 10/2 and 12/2 will be found to, once someone comes up with a n installation drawing showing the 12/2, then I think this thread will be pretty well exhausted.
So we have to think up another controversial subject to pursue to keep interest in this forum up.
Quinn
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Quinn:
to funny...
check back tonight or in the morning, i have been looking at the lister prints, i still have to source the later 6/1 print, but if as suspected i have the
"FORMULA"
"and its mine,,, all mine.... muwwwwaaahahahahaha"
with the formula, geometry, and physics to support the dimensions of the block this should prove to be fun.
what do you wanna bet there will be those to argue the validity?
hell i might even argue with me,
there is nothing wrong with me, wrong with me,,, wrong with me...
bob g
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I had a boss once who told me never to talk about sports, politics or religion with clients. It's a good rule, and one that has brought me peace of mind and equanimity over the course of my life, both professionally and personally.
Are the Yankees a piece of shit or what?
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There was a previous thread with a link to a PDF of a doc from the 1950's that had all the nitty-gritty details for making a solid mount for a piece of machinery.
I only skimmed through it in passing, but from memory :
It took into account differing soil types and loading in lbs/sq inch, mass distribution and block shape and details for determining the mass of concrete need to keep vibration/displacement to an acceptable limit. At the base of all the calculations was the machine manufacturers specs on how much force the machine generates at a certain frequency/RPM. Without those specs, block design simply reverts to "overkill" mode. Which is what I suspect is the case with Lister.
If not, has anyone seen any Lister specs of that type to prove the case that it's a properly engineered block design?
Listeroid specs would be hopeless, you'd never be able to get two machines side by side with equivalent specs. :D
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Well, that and the fact that the Indian manuals blatantly rip off the Brits' work without adding anything noteworthy of their own. The fact that there is that caveat about soil conditions indicates that nothing's cast in stone, er, concrete.
I'm thinking maybe we should talk about detergent vs. non-detergent oil. No . . . that's been done.
Darn!
Quinn
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I'm thinking maybe we should talk about detergent vs. non-detergent oil. No . . . that's been done.
Darn!
How about BHP versus power? Can't remember how that one finished! :D
Brian
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1936 LISTER BOOK NO 103 says this
Fixing
The Engine should be securely fastened and reasonably level.
Important Note. For belt drive always arrange the inside edge of
driving belt as close to Engine bearing as possible. Where "Fast" and
"Loose" pulleys are used always arrange the pulleys so that the drive is
taken on the side of the pulley nearest to the Engine bearing.
Attention to the above will prevent undue strain on the bearings due to
overhang.
A slightly later book 103 says this
.
Fixing
The Engine should be securely fastened and reasonably level.
Important Note. For belt drive always arrange the inside edge of
driving belt as close to Engine bearing as possible. Where "Fast" and
"Loose" pulleys are used always arrange the pulleys so that the drive is
taken on the side of the pulley nearest to the Engine bearing.
Attention to the above will prevent undue strain on the bearings due to
overhang.
EXTRA HEAVY BELT DRIVES
If the machine which the Engine is to drive makes the use of an exceptionally
heavy or tight driving belt unavoidable, the driving pulley should be supported
between two bearings on an extension shaft with a flexible coupling to connect it
to the engine. Pulley shaft bearings and engine should be mounted on a substantial
steel girder or concrete base.
1952 LISTER BOOK NO 103 says this
INSTALATION
The Engine must be installed where a generous supply of ftesh air is assured.
A portable electric light is recomended in addition to the fixed lighting of the engine room.
The most convenient hight for the crankshaft is 27in above the ground.
Keep the Exhaust and Water Pipes as short as possible.
Leave a space of about 3 feet all around the Engine for ease of access and maintenance.
Foundations
Our standard foundation drawings give the dimensions of suitable concerte beds. These
dimensions are the minimum for a good solid subsoil and modifications will have to be made where
the subsoil is soft water logged or otherwise of a special character.
Set the Engine as level as possible packing under the Engine feet with thin metal strips, placed
aa close as possible to the holding down bolts.
Portable models
Place Portable Models in as level position as possible.
1983 LISTER BOOK 103 says this
INSTALATION
The Engine must be installed where a generous supply of ftesh air is assured.
A portable electric light is recomended in addition to the fixed lighting of the engine room.
The most convenient hight for the crankshaft is 27in above the ground.
Keep the Exhaust and Water Pipes as short as possible.
Leave a space of about 3 feet all around the Engine for ease of access and maintenance.
Foundations
Our standard foundation drawings give the dimensions of suitable concerte beds. These
dimensions are the minimum for a good solid subsoil and modifications will have to be made where
the subsoil is soft water logged or otherwise of a special character.
Set the Engine as level as possible packing under the Engine feet with thin meral strips, placed
aa close as possible to the holding down bolts.
Portable models
Place Portable Models in as level position as possible.
All the above references are out of genuine lister engine books from 1936 to 1983 and they dont tell very much but what they do point out is that these engines were used as portable engines They were used in cement mixers during and after the war and lot of other portable applications The size of the concrete block mentioned at
http://www.oldengine.org/members/diesel/Technical/51P3data.htm is just for mounting the engine on.
The heavier concrete block is probably for the startomatic units
1952 Startomatic manual for 6hp 650rpm 2.5kw sets says this
FOUNDATION
Mount the generating set on a concrete block 2' 3'' deep. 3'' above floor level and 3''
wider and longer than the baseplate . When pouring the concrete leave four square holes
4'' square x 15'' deep for the holding down bolts.
When the concrete block is hard the set should be levelled up and a grouting mixture of cement
and sand worked in under the bearing surfaces of the baseplate. The bolts should be grouted in
but not tightened down untill the grouting has set hard.
The 1969 Startomatic manual for the 6/1. 3kw sets and 8/1. 4.5kw sets says exactly the same as above. but in the back of the the manual is drawing no 4526EP. This gives the layout of the engine room and this gives the dimensions for the concrete block. These dimensions are 4' 4'' long 2' 1'' wide and 1'8'' deep including 5'' above the floor. This is totally different to what it says at the begining of this manual.
Also included in drawing no 4526EP is this note just above the description in the bottom right hand corner
NOTE:-
WHEN FLEXIBLE MOUNTINGS ARE
FITTED FLEXIBLE EXHAUST AND
FUEL PIPES MUST BE USED
INSTRUCTIONS FOR 6/1. 8/1. 12/2 AND 16/2
PUSH BUTTON REMOTE CONTROLLED PLANTS Says this aswell
Foundation. A heavy block is required on which to stand the plant.
If a belt driven set is being installed, with seperate beds for engine and
dynamo or other driven machine, the two beds should be connected by a stout
section of re-inforced concrete floor. Care must be taken to ensure that
the engine bedplate beds evenly on the concrete block. To insure this,
the plant bedplate should be grouted in (i.e. it should be let down on to
a bed of soft mortar). It is an advantage to place a piece of steel plate
about 3'' x 1/2'' between the engine feet and the concrete block when an engine
alone is installed. The whole should be grouted as above.
Where a bedplate is not supplied, the engine or plant supports must not
grouted in; this will facilitate easy removal of each component.
Plants and engines should be raised above floor level on a plinth so that
the crankshaft is about 27'' above the floor for convenience of starting and
maintenance. The concrete used in foundation blocks should be 1 part
cement, 2 parts sand, 3 parts gravel up to 1 1/2''.
Foundation Bolts. Foundation bolts of combined set should not be tightened
down too much, particularly with fabricated steel bed plates.
I hope this information is of some interest
Mick
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NOTE:-
WHEN FLEXIBLE MOUNTINGS ARE
FITTED FLEXIBLE EXHAUST AND
FUEL PIPES MUST BE USED
Well, thats certainly pretty interesting.
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things that make you go "hmmmmmm"
boy that just about kills this one, i worked last night to arrive at the mathematical formula to explain the concrete base of a 3/1 and a 5/1,
i got the formulae worked out for the depth and length, but have had a bit of trouble working out the width formula
seems like a mute point as Mick's post seems to have lister all over the place with "suggested" mounting.
what is interesting is the fact that lister did take into account sound engineering practice for concrete, with the spec of keeping the mount bolts at least 3 inches
away from the edge of the block.
geometrically the 3/1 and 5/1 concrete block as printed illustrates some interesting things, that i worked out mathematically, but the math does not support their later
recommendation.
from a side view of the engine, if one takes a line (vector) from tdc at a point in the center or the piston, down thru the middle of of the engine mount bolt center and continues the line downward into a block area, what you will find is this line will go to the outer bottom corner of the block, or rather just inside that corner, which would stand to reason that any force sent down that vector would go thru the block to the ground and not out the side of the block.
if another line is drawn from the same point tdc/center of piston thru the other mount bolt it will intersect at the same point but on the opposite side of the block bottom. which is interesting.
couple that with the relationship between the crankshaft centerheight as installed of 12.5 inches and bolt c/c of 13
with the mount block they used to keep the same ratio or aspect ratio with the block as part of the engine the block length works out to be 27.5", which is very close to the 28" spec.
to determine block width the line is started from tdc/piston center down thru the center of the main brgs to the bottom of the block, where it comes very close to the edge of the 22" dimension spec by lister,
this clearly indicates that all force vectors are straight line thru the point of origin, thru the main brg centers, down the crankcase and follow the same vectors down thru the bottom of the concrete without exiting the sides of the block, in all aspect, front, side or what ever
this would mean that likely the 15" deep, 22" inch wide, and 28" long concrete block is probably the minimum size for a 3/1, 5/1 6/1 and probably most of the other single cylinders.
or all of this can be explained in mathematical formulae, but it seems to be almost a lost cause at this point.
it would appear now conclusively that lister had a wide variance in recommendation of mounting, including flexible mounting.
interesting indeed,
hell even grouting concerns are all over the board, some stated no cast in bolts, no grouted in bolts , now grout them in and don't torque until set?
and whats the deal with don't torque them down too tight if on a steel frame? what's too tight? whats too loose?
they may and likely was alot of solid engineering in the engine proper, alot of higher math, and equations, but...
seems like the mounting was a bit more seat of the pants, or trial and error, or "run what ya brung"
well i guess i got my answer, just not sure what it is, or whether i learned anything from it.
bob g
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Mea culpa. The block was RA Lister's standard foundation but it was apparently not a requirement for warranty.
I still believe that a rigid foundation is superior for the CS. I don't really wish to argue about this any more, but perhaps this will be of interest. Consider this:
(http://upload.wikimedia.org/wikipedia/en/f/f9/BrittleAluminium320MPA_S-N_Curve.jpg)
There's a non-linear relationship between stress on a metallic element and its projected lifespan. Holding an engine rigid assures that you stay on the low end of this scale, ensuring many millions of cycles from the crankshaft et al. Flexible mounts will sometimes absorb stress, but since the single cylinder is inherently somewhat unbalanced, there will be harmonics that cause undue stress. For instance the engine as a whole may have upward momentum during the power stroke, thereby stressing the crank as much as many many normal cycles.
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Pro:
thanks for the graph, but please consider the following
aluminum, forged, milled, cast and even in alloys has a dramatically lower life cycle than cast iron or forged steel.
aluminum and its alloys to a lessor extent exhibit rapid decline based on stresses, vibration, bending etc.
what would be interesting is to see the same graph for forged steel (crankshaft) and cast iron (cylinder block)
i think you will find a much different looking graph
but your point is well taken.
i have to tell you though i am a bit disappointed in the failure to find proof of concept or an actual formula (even if it was a generic, seat of the pants thing)
now what are we going to argue about?
bob g
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what would be interesting is to see the same graph for forged steel (crankshaft) and cast iron (cylinder block)
i think you will find a much different looking graph
I think all structural metals exhibit a non-linear relationship between cycles and stress amplitudes, albeit to different degrees.
but your point is well taken.
i have to tell you though i am a bit disappointed in the failure to find proof of concept or an actual formula (even if it was a generic, seat of the pants thing)
now what are we going to argue about?
Chevy vs Ford? Emacs vs Vi?
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http://www.oldengine.org/members/diesel/Technical/51P3data.htm
equations as follows
step one, determine the depth of the concrete block
Bd=A*5 Bd= block depth
A=block height above floor
step two, determine the length of concrete block
Bl=(Bd+Ccl)*(Ccl/Mc) Bl= block length
Bd=block depth
Ccl= crankshaft centerline to base distance
Mc= mounting base of crankcase bolt center to center distance
step three, determine the width of concrete block
Bw= (((Mc-MBc)/Ccl)*Bd)+Mc Bw= block width
Mc= mounting base of crankcase bolt center to center distance
MBc= main brg center to center distance
Ccl= crankshaft centerline to base distance
Bd=block depth
these formula's give the minimum specifications for the concrete block, there is also an included margin so that force vectors intersect and do not exit out the side or corners but rather within the perimeter of the bottom surface of the concrete block.
have fun with this one guys :)
it took a bit of time to arrive at, now to see if it correlates to other block recommendations
i hesitated to publish this but am tired of the subject and it answers my original question, so until someone can explain the specification (of the above linked engine 5/1) with documentation i am done argueing it.
further i am not about to argue applicability to other lister spec's engine mount concrete blocks, God know's how they arrived at the other spec's, perhaps the above equations will suffice to
explain the other engine only concrete mounts, perhaps it won't ,,, who cares?
my bet is if lister engineered the concrete block for the engine, the engineering went into the earlier efforts and was mangled in later years by other concerns such as the need for more mass to tame engine's that likely were balanced to a lessor standard of their earlier engines. who knows and really at this point who cares.
bob g
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Lots of very successful people, creative in their own right have said: If you don't know the answer, surround yourself with those who can figure it out for you.
When Edison was asked to show his mathematical formulas on the theory of the electric light he replied something to the fact that he wasn't a mathematician, but an inventor. Inefficient perhaps but ultimately effective.
Use your mind according to it's unique talents. If you are incapable of doing the math, like myself don't let it stop you. You will eventually find the answer.
Thanks for the equations on the block, Bob.
Guy is a whiz and I read along as best I can. He is trying to teach a person to "fish" rather than just spout the answer. Even if he gave the answer to us, and the equations, would I be able to follow them and understand how he got to the answer? Maybe. Anyway, downloaded those PDF's (THANKS!) but I have small kids and little extra time. GF has one on the way. If he is like anyone else, he will be in the same boat soon.
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Bob where did you get the the formulas to calculate the block size?
I'd like to read that over in depth....
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Doug:
"where did i get the formula's?"
i am holding that one close to the vest for a while
at least until i see the spec's on the ton block of concrete, and i see some equations out of Guy.
bob g
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Bob, I did not see a variable in the formula for the density of the concrete and it's probably an average figured in as a constant. Just curious, and you don't have to give any secret equations but if you changed the density of the block substance to something heavier, will the dimensions change? Could it make the block more compact?
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the density of the concrete block was not a consideration, for a couple of reasons
1. because of how the vector forces work within the block, density has little interaction, and
2. the fact that the amount of water used, mix ratio's, working time, and setting conditions all have radical effect on the overall density and stregth of the end product.
you can reduce the size of the block a bit more, if you want to first reduce the height above the floor (Bd), but from a practical standpoint the block dimensions shown for the 1936 5/1 are should be seen as the minimum from a strength standpoint of the concrete inself.
bob g