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Author Topic: concrete vs resilient mounting  (Read 44270 times)

Quinnf

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Re: concrete vs resilient mounting
« Reply #30 on: October 06, 2006, 08:09:08 PM »
Were any specs given for the hold-down bolts?

Quinn
Ashwamegh 6/1, PowerSolutions 6/1 "Kit" engine, and a Changfa R175a that looks like a Yanmar I once knew

Procrustes

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Re: concrete vs resilient mounting
« Reply #31 on: October 06, 2006, 08:30:41 PM »
Procrustes
You quote the part of the conversation, which supports your view, while omitting the part below, which does not. 

Quote
“……As you rightly say technology has moved on and I do not doubt now
that some form of resilent mounting could be used providing good engineering
practices are adhered to….”

The part which "supports my view"?  Scott, he admittedly knows nothing about CS engines, much less is he an expert.  He tried looking up the answer but didn't get that right, because as Smokey just quoted, the recommendation was a concrete block.

About the technology has moved on, sure it has -- Kubota makes solid engines that are convenient to mount.

I don’t think anyone ever said that a big block of concrete was not a suitable mount.  The question was, is it the ONLY suitable mount?

Suitable for what?  For the maximum safety and reliability, my money would be on the RA Lister engineer's advice.  They are the authority.

The information is accumulating that says it is possible to mount a Lister type engine on resilient mounts.  This info is from the opinions of two engineers I spoke with, in addition to the opinion of this person at the Lister Petter company.

Everyone is entitled to his opinion; I give more weight to those from people who are experts in their fields, in this case the engineers and this representative of the Lister Petter company.

The person from Lister didn't pretend to know anything about CS engines, so it's nonsensical to appeal to him as an authority just because he happens to work at that company.  The information accumulating about resilient mounts is negligible compared to years of engineering effort,  millions of runtime hours and  untold failure analyses under RA LIster's belt.  The same goes for the advice of two random engineers.  Why are you betting on the engine's design, yet weight the advice ot two engineers who don't work closely with Listers higher than the advice of the engine's designers?

Procrustes what exactly would you need to see to convince you that a resiliant mount is acceptable, Just curious?

I respect the authority.  If you think they are musty old farts, then you why not take the same view of their engine and get the Kubota instead?

Between the money you paid your engineer, steel, fabrication, resilient mounts, etc you are going to spend a multiple of the $100 that a block would cost you.  You'll no doubt end up with something cooler and more portable.  I might well do it the same way in your shoes.  I continue however to think it ridiculous to hear people say the RA Lister mounting spec is wrong for their own engine.  These were gifted, accomplished men who invented the closest thing to a timeless engine there is.  Don't you think it's presumptuous to say they're wrong?  And if they're old fashioned, why waste your time and money with the engine?  No doubt other parts besides the mount are old fashioned too.

mobile_bob

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Re: concrete vs resilient mounting
« Reply #32 on: October 06, 2006, 08:55:18 PM »
a recommendation from lister for the use of concrete does not constitute the mandatory use of concrete.

has anyone found wording that this has to be used? can you post it? word for word?

words have meaning, and it is very obvious that interpretations can be varied.

we are getting closer, but still not there.

and what about the portable units,, the recommendation is to mount them as close to level as possible,, on what?
if it is portable, do they go on to state that the portable unit has to have a ton of concrete to mount it to when moved to that location?

a portable unit certainly is not portable if it has to be mounted to a ton of concrete at each location?

anyone?

bob g
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Smokey

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Re: concrete vs resilient mounting
« Reply #33 on: October 06, 2006, 09:50:23 PM »
I have not encountered a  recommendation concerning bolt grade or size, but I have not read the booklet in their entirety either.  My Metro came with four 1/2" diameter J- bolts of unknown quality. I will assume the are made of dried peanut butter and replace them with Grade B7 Alloy Steel stud from Mcmaster-Carr. Some have suggested the use of 3/4" diameter studs, I am not sure that the holes in the base lugs on my engine are large enough to accomodate that size.

Did any one else read the papers that I linked to in the other thread?  If you did you will see that it is not a "no brainer" with respect to the design of rigid concrete foundations and Lister alludes to this in the quote I posted earlier.

 I read "Principles of Foundation Design for Engines and Compressors," by Newcomb and "Don't Gamble on Machinery Foundations" by William Kauffmann.  If you tihink you can just pour some concrete into a form of the dimensions recommended by Lister and neglect the underlying soil mechanics, you my end up disappointed.   If you have subsoil that is dry gravel, it will tamp down firm you will probably be fine with the Lister design foundation (I am assuming it is the same as the one shown in my Metro owners manual).  If you have something more like damp clay you may have some problems inless you increase the foundation bearing area.

Also learned that conventional foundations and resiliant mounted foundations use entirely different design strategies with respect to viibration and natural frequency.  With a resiliant mounted system you want the lowest excitation frequency to by at least 3 times greater than the natural frequency of your resiliant mount system.  With a conventional foundation you want the natural frequency of the soil to be 2 or more times greater than the excitation frequency.  Further, you don't want narrow tall foundations because you could end up with a rocking couple.  Also it appears that in 1951 a foundation design rule of thumb was foundation weight about 4 times the machine weight.  But please don't take my ramblings as gospel because I don't know squat about soil mechanics. Go read the documents yourself and make up your own mind, as I very well may be wrong on all of this.
Metro 6/1, ST5 Genhead

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phaedrus

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Re: concrete vs resilient mounting
« Reply #34 on: October 06, 2006, 10:08:31 PM »
Reading all these posts I see a couple of things I'd like to remark about.

1) "Resilient" mounting is, as y'all use the term, it seems to me, undefined. A damping but flexible modern elastomeric mounting pad, such as we (I'm a millwright) often use mounting large forced-draft fans is pretty forgiving and cheap. Provided the lister type was well balanced I expect that it'd run on pads like those more or less forever. BUT, if the engine became unbalanced while running it might do quite a bit of damage before things came to rest. Therefore I’d think hard about caging those pads. The reason we use these pads has little to do with the machine they support though - instead they're used to isolate one machine from another, and from structures. More on this below. The pads and the concrete are really more similar than you all mostly seem to think…

2) There's a big difference between steel and cast iron. Cast iron is a damping material - really hard to get it to resonate. Steel is much more flexible - depending on the design of an Nth steel weldiment. I’d be very careful about the design of a steel sub-frame, though, imho, there's nothing wrong with a well thought out and rigid one.

3) I decided to mount my 6 - 1 on top of 60 cubic feet of concrete tied into bedrock with epoxy-rebar ties, and topped off with a 160 pound steel plate grouted to the concrete - leveled with a "98" precision level. Why?

Several reasons

It's esthetically pleasing to me - that's important, and it gives the isolation that keeps vibration out of the engine house wall footings.

It’s high enough off the floor that I don’t have to bend or crouch.

The 60 cubic foot slug of concrete derives from Marks Handbook of Engineering (1940 ed) Marks gives the empirical formulas for various types of “gas engines”. (That’s an old fashion term and simply means recips that aren’t steam.) I'll quote from page 1334...

“Foundations. The reciprocating weights of gas engines are greater and the speeds of rotation generally higher than in the case of steam engines, necessitating more mass to the foundation, which should always be carried down to a firm footing. Concrete floors and the walls of the engine house should not be tied rigidly to the foundations, because of the vibration The average volume of material in foundations for the different types of engines may be taken as follows:

For horizontal engines without outboard bearing, 14 to 18 X bhp cu ft.
For horizontal engines with outboard bearing, 19 to 22 X bhp cu ft.
For vertical engines without outboard bearing, 7.7 to 8.8 X bhp cu ft.
For vertical engines with outboard bearing, 9.8 to 10.5 X bhp cu ft.”

The 6-1 is a vertical with outboard bearing, and the arithmetic is obvious. The 6-1 Lister type needs, according to Marks, about 2 yards of concrete or a bit more. But, regardless of this mass – the handbook emphasizes the necessity for isolation. This guide-line is, as should be obvious, for infinite life-cycles and zero cumulative vibration damage to the housing structure.

Marks 1940 seems about right for an "oldtimey" engine. Moden engineering handbooks and foundation formulas are going to let you get away with a lighter foundation, of course, but it that so important?

Looking at the implications of Marks, what seems really important about mounting is 1) that the engine not introduce vibration into adjacent structures, and 2) that the engine is supported firmly so that it can't damage itself. That's consistent with the old Lister instructions, and also consistent with modern damping-vibration pad mounting - if done right.

Peace.
if ya don't ask permission they can't deny it...

Quinnf

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Re: concrete vs resilient mounting
« Reply #35 on: October 06, 2006, 10:31:36 PM »
Smokey,

I read a couple of the papers with interest.  I won't pretend to be well versed in the engineering, though I do remember the physics of simple harmonic motion, spring constants, damping, etc. from college nearly 30 years ago.

I wonder what is expected to be the dynamic motion of an engine/generator mounted to a rigid frame, itself coupled to the earth via the resilient mounts that everyone has been talking about.  It seems to me that if the mounts are tuned right, the motion of the engine/generator should be very slight, perhaps invisible to the eye.  And if that is the case, what is the difference between mounting the contraption on resilient mounts vs. just bolting it to something heavy enough to keep it from rattling?

Quinn

Ashwamegh 6/1, PowerSolutions 6/1 "Kit" engine, and a Changfa R175a that looks like a Yanmar I once knew

Smokey

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Re: concrete vs resilient mounting
« Reply #36 on: October 06, 2006, 11:02:47 PM »
Quinnf,

I think that if the mounts are engineered properly to the application,  that the relatively low mass of the engine/grame/generator system will have relatively high vibration amplitude compared to a similar mounting system that employed much higher mass. G-I has touched on this in his post about designing a steel frame http://listerengine.com/smf/index.php?topic=1097.0.

What I have posted here is not based on personal experience, I am no expert by any means.  Its just my understanding of the problem based on what I have read and conversations I have had with people smarter than I.  In fact I am at the design stage of the foundation of my Merto 6/1 so I guess you could say that I am a motivated student in this area,

A friend of mine mounted his listeroid genset on rubber mounts.  It moves around a bit, there is a both vertical and a horizontal vibration motion component.  He is satisfied, I have reservations about what the vibration will do to fuel lines, fuel tank, etc in the long run.  To each his own.
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SCOTT

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Re: concrete vs resilient mounting
« Reply #37 on: October 06, 2006, 11:47:35 PM »
It seems that those who believe that the ONLY way to mount a Lister type engine will continue to believe so no matter what. 

Procrutes  you said
Quote

Why are you betting on the engine's design, yet weight the advice ot two engineers who don't work closely with Listers higher than the advice of the engine's designers?

Well that is not what I am doing. One of the engineers I spoke with works for Lister Petter company, The other’s job is to design systems for stationary engine mounting.   The third person I mentioned was the one who responded to the e-mail I sent to the link on their web site and I very clearly pointed out in my post that this was not coming from the engineer I spoke to at Lister Petter. 

Pro said

Quote
Suitable for what?  For the maximum safety and reliability, my money would be on the RA Lister engineer's advice.  They are the authority.

I could not agree more, that’s why I contacted them.  The engineer I spoke with at Lister Petter said as long as the frame was very rigid a resilient mount would work, he suggested I speak to the people at Ebco   http://www.ebco-inc.com .
And before someone tries to negate the opinion of the Lister Petter engineer just because he did not work on the design team for the Lister 6/1 let me quote an often used phrase by another member  “….the laws of physics have not changed…..” 

I am confident that a good engineer can grasp the forces involved in a Lister engine, they work with this stuff on a daily basis.  For the people here, myself included this is complicated, for a trained engineer it is not, its just another design and set of quations .  They get the physics and know the math.


Quote
These were gifted, accomplished men who invented the closest thing to a timeless engine there is.  Don't you think it's presumptuous to say they're wrong?  And if they're old fashioned, why waste your time and money with the engine?  No doubt other parts besides the mount are old fashioned too.

I don’t recall anyone ever saying the engineers were wrong, to the contrary, they did a great job and a concrete mount works well.  I suggest it is presumptuous to dismiss the opinion of 2 engineers one of whom works for Lister just because the original suggested mounting method was concrete.  But along with the concrete come an unwelcome side effect, vibration transmission.


What some people miss or confuse is that omission of a mounting method DOES NOT mean exclusion of that method.  Lister never mentioned using a block of cast iron the same dimensions as the concrete block, would that not work as well? If Lister said that resilient mounting was not suitable for these engines because of x that would be a different story.


Again I believe a concrete mount will do the job, but I require more than just a solid engine mount, I require reduced vibration and noise transmission to areas outside of the engine room.  If I did not require this I would not have looked into alternative mounting options.  I think many people would benefit if we as a group came up with options. 

Everyone benefits from more choice. 

Scott
net metering with a 6/1 in Connecticut
12/1
6/1

dkwflight

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Re: concrete vs resilient mounting
« Reply #38 on: October 07, 2006, 12:33:15 AM »
Hi
I've been following this thread for a while. It seems to me the engine you want to mount is the first place to start. Some of the poorly made engines are WAY out of balance and some are not. some balance weight is in order
Mine happens to be pretty well balanced and I am running at 650rpm instead of the 1000 it is suposed to develop it's rated horse power.

I put it on a heavy skid because I wanted to be able to pull it on a trailer and move it if I wanted. It does a rather sedate little dance when running. The engine, skid and gen head weighs around 2500lb.

If the engine is to be run  in the same place for many years then mount it on concrete. The lump of concrete should weigh double the engine. I think. The bigger the better. If your engine foundation is to be surounded by a concrete floor you should put foam insulation around the engine foundation to keep any movement, viberation from transmitting to the surounding structure.
Just my $.02
Dennis
28/2 powersolutions JKSon -20k gen head
Still in devlopment for 24/7 operation, 77 hours running time

mobile_bob

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Re: concrete vs resilient mounting
« Reply #39 on: October 07, 2006, 01:17:27 AM »
Scott:

when you get tired of beating the drum,,, let me know,,, i am resting and waiting  :)

i simply cannot believe how narrow minded some folks appear to be

you, i and others while exploring the possibility of useing a resilient mount have never said that concrete is the wrong way to mount a lister

some folks are so selective in what they take from reading a post it leads me to really wonder about the exact wording of the lister original recommendation of using concrete.

to some folks the fact that lister even mentions the word "concrete" makes its use mandatory, let alone the vagaries of a "recommendation"

and i have stated this fact too, and i am glad to see at least one other see the logic
"just because lister makes no mention of resilient mounts does not negate their possible use"

and you are spot on,,, if instead they had stated..
"we do not recommend the use of resilient mounting designs" or "we don't recommend resilient mounting designs, because of..."  then yes one would have a bold uphill battle to get support for using them.

before some clever guy comes back with "well they didn't mention resilient mounting schemes because they were not around then"  that clearly is not the case, they were in widespread use way before lister built the diesel. or .. "they did not anticipate the need or anyone trying to use them", that dog don't hunt either!

tag me,, tag me... :)

bob g
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Guy_Incognito

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Re: concrete vs resilient mounting
« Reply #40 on: October 07, 2006, 02:43:25 AM »
I wonder what is expected to be the dynamic motion of an engine/generator mounted to a rigid frame, itself coupled to the earth via the resilient mounts that everyone has been talking about.  It seems to me that if the mounts are tuned right, the motion of the engine/generator should be very slight, perhaps invisible to the eye.  And if that is the case, what is the difference between mounting the contraption on resilient mounts vs. just bolting it to something heavy enough to keep it from rattling?

Quinn

Aha! I'm glad someone asked. I've been tinkering with the numbers now for about a week. Before everyone rolls their eyes  ::), these are only indicative and in the vertical direction only, your mileage may vary blah blah blah.

For me, with my airmounts - I calculate a jiggle of about 1mm above and below the centreline at 650RPM. This is with a few parameters :
- Imbalance forces of about 15kg around a stroke of 138mm - 5kg of that is typical piston mass. The rest is the imbalance due to a 50% bobweight, and I've added a bit more for luck/combustion force, but it really needs to be factored in better.
- A supported mass of 1000kg.
- A spring rate of my airmounts of 13kN/m

This gives me a resonant peak that's at about 70RPM for imbalances, 35RPM for firing pulses, and at 650RPM, total forces transferred to the ground are about 25kg. As the mounts store the energy that isn't transferred to the ground and give it back to the system being supported, the jiggle is increased compared to something that absorbs/transfers that energy onwards like the concrete.

If I plug some silly numbers (for me  ;D ) into my spreadsheet for concrete, say 2500kg, spring rate to the subsoil of 100MN/m and keep the rest the same , I get :

A deflection of about 0.05mm up and down, resonant points at 1300/650RPM(Hmm. Better add more concrete!) and at 650RPM, total force transferred to the subsoil of about 500kg. Probably actually a lot more if we did accidentally strike resonance as you're effectively throwing and catching a 2500kg concrete block.

Procrustes

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Re: concrete vs resilient mounting
« Reply #41 on: October 07, 2006, 03:52:53 AM »
i simply cannot believe how narrow minded some folks appear to be

you, i and others while exploring the possibility of useing a resilient mount have never said that concrete is the wrong way to mount a lister

Bob, you've laid into folks on this very board for proposing modifications to the 6/1.  You pointed out in great detail that such changes aren't known to be right until they've been field tested for hundreds and thousands of hours and the failures have been analyzed.  How is what you are doing any different?

It's commendable to explore the use of resilient mounts is commendable and I'll read the results with interest.  Speculating whether they're as good as the block is just that, speculation.

some folks are so selective in what they take from reading a post it leads me to really wonder about the exact wording of the lister original recommendation of using concrete.

Smokey posted it earlier in this thread.  It plainly says to use a block of at least a particular dimension.

to some folks the fact that lister even mentions the word "concrete" makes its use mandatory, let alone the vagaries of a "recommendation"

I don't know what you mean by 'mandatory', you said that earlier too.  It's no more mandatory than that you keep it topped off with oil.  Either way you're out of spec and they can void the warranty.  It's not a 'recommendation' per se, it's a specification.

and i have stated this fact too, and i am glad to see at least one other see the logic
"just because lister makes no mention of resilient mounts does not negate their possible use"

and you are spot on,,, if instead they had stated..
"we do not recommend the use of resilient mounting designs" or "we don't recommend resilient mounting designs, because of..."  then yes one would have a bold uphill battle to get support for using them.

before some clever guy comes back with "well they didn't mention resilient mounting schemes because they were not around then"  that clearly is not the case, they were in widespread use way before lister built the diesel. or .. "they did not anticipate the need or anyone trying to use them", that dog don't hunt either!

You're running toward the wrong goal line IMO.  Lister knew full well about resilient mounts, yet specified the concrete block.  What's the obvious conclusion?

Procrustes

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Re: concrete vs resilient mounting
« Reply #42 on: October 07, 2006, 04:22:39 AM »
It seems that those who believe that the ONLY way to mount a Lister type engine will continue to believe so no matter what. 

Not so.  It's the proven way, and the conclusion of years of engineering, countless failure analyses, and millions of hours of runtime.  I'm fine with other mounts, but it's unrealistic to think they will be better.


Procrutes  you said
Quote

Why are you betting on the engine's design, yet weight the advice ot two engineers who don't work closely with Listers higher than the advice of the engine's designers?

Well that is not what I am doing. One of the engineers I spoke with works for Lister Petter company, The other\u2019s job is to design systems for stationary engine mounting.   The third person I mentioned was the one who responded to the e-mail I sent to the link on their web site and I very clearly pointed out in my post that this was not coming from the engineer I spoke to at Lister Petter. 

But that's exactly what you are doing: you are favoring a small set of information over the conclusions of years of engineering, countless failure analyses, and millions of hours of runtime embodied in the mounting specification.    Just a little while ago you took the word of a clerk who admitted not to know about the old engines to be the word of Moses.


Pro said

Quote
Suitable for what?  For the maximum safety and reliability, my money would be on the RA Lister engineer's advice.  They are the authority.

I could not agree more, that\u2019s why I contacted them.  The engineer I spoke with at Lister Petter said as long as the frame was very rigid a resilient mount would work, he suggested I speak to the people at Ebco   http://www.ebco-inc.com .
And before someone tries to negate the opinion of the Lister Petter engineer just because he did not work on the design team for the Lister 6/1 let me quote an often used phrase by another member  \u201c\u2026.the laws of physics have not changed\u2026..\u201d 

I am confident that a good engineer can grasp the forces involved in a Lister engine, they work with this stuff on a daily basis.  For the people here, myself included this is complicated, for a trained engineer it is not, its just another design and set of quations .  They get the physics and know the math.

You can find an engineer who will mount your engine on haybales, and plenty of ME's helped design the Tacoma Narrows bridge, and the Reliant K.  The epitome of research on mounting Listers no doubt occurred during their manufacture, by the same team that designed the engine.  You find an engineer who will gladly take your money to build a teleporter or a Heisenberg Compensator (http://seattle.craigslist.org/sno/tls/216699897.html).  That doesn't prove anything.  Some engineer at Lister is charged with answering customer's questions.  Who's to say he knows anything about an engine not made since '81 (?).  What particular expertise is this guy guranteed to have?  Does he know better than the folks who designed the Lister CS?

Quote
These were gifted, accomplished men who invented the closest thing to a timeless engine there is.  Don't you think it's presumptuous to say they're wrong?  And if they're old fashioned, why waste your time and money with the engine?  No doubt other parts besides the mount are old fashioned too.

I don\u2019t recall anyone ever saying the engineers were wrong, to the contrary, they did a great job and a concrete mount works well.  I suggest it is presumptuous to dismiss the opinion of 2 engineers one of whom works for Lister just because the original suggested mounting method was concrete.  But along with the concrete come an unwelcome side effect, vibration transmission.

On the contrary, it is presumptuous to believe that three professionals who have likely never laid eyes on a CS to know more about mounting it than its designers.

What some people miss or confuse is that omission of a mounting method DOES NOT mean exclusion of that method.  Lister never mentioned using a block of cast iron the same dimensions as the concrete block, would that not work as well? If Lister said that resilient mounting was not suitable for these engines because of x that would be a different story.

That's a poor argument.  You car specifies that you use gasoline, but doesn't explicitly say not to run it on ketchup.

A metal block may well work, I haven't a clue.

Again I believe a concrete mount will do the job, but I require more than just a solid engine mount, I require reduced vibration and noise transmission to areas outside of the engine room.  If I did not require this I would not have looked into alternative mounting options.  I think many people would benefit if we as a group came up with options. 

Isn't that a different issue?  I don't know why you can't reduce vibrations from a block as well as from a frame.

mobile_bob

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Re: concrete vs resilient mounting
« Reply #43 on: October 07, 2006, 05:09:48 AM »
Pro:

"Bob, you've laid into folks on this very board for proposing modifications to the 6/1."

i am getting to be an old fart and my memory is as short as something else i have, perhaps you can remind me of my having laid into folks on proposed alterations to their engine, some examples please?

"Speculating whether they're as good as the block is just that, speculation."

you are absolutely right at some level, but good as a block for what purpose?
i have not beat up the use of a block of concrete, and would use one in many instances myself.

i damn sure can speculate that i can get the result i need with the use of resilient mounts as will many folks, any harm in speculation, or working toward that goal?

how far would mankind have gotten if we don't challenge what was done before? how do you further your knowlege of anything if you don't question?  how do we know what we are told is the truth if we don't investigate and ask for some level of proof?

" It plainly says to use a block of at least a particular dimension."

oh it does, does it?

" Our standard foundation drawings give the dimensions of suitable concrete beds.  These dimensions are
the minimum for a good solid sub-soil and modifications will have to be made where the sub-soil is soft, waterlogged,
or otherwise of a special character."

"These dimensions are the minimum for a good solid sub-soil",
what is good, what is the margin of error? this is subjective and leaves room for interpretation

"modifications will have to be made where the sub-soil is soft, waterlogged,
or otherwise of a special character."

boy that is sure specific as mud, subjective as hell, and no specific details as to how to modify to fit certain conditions, some of which might very well be totally outside the parameters for their suggested specifications, then what?

"Portable Models
   Place portable models in as level a position as possible."

what about these portable units? obviously they must have made one or two, did they not warranty those? how did they get around the use of concrete on these? is it not possible that perhaps the portable units were of the upper 10% of the group in being well balanced?

" Lister knew full well about resilient mounts, yet specified the concrete block.  What's the obvious conclusion?"

the obvious conclusion can be many

1. they didnt work with the resilient mounts period,

2. they did and found them not to work with average balanced engines

3. they like every other manufacture of engines left it to the end user to work out suitable resilient mounts if they wanted them.

4. etc. put your reason here

obviously there can be no "obvious" conclusion to be drawn.

proofs don't come from "obvious" anything, they come from "facts"

if you have followed this debate closely you will notice that there has been all sorts of assertions
that is what i have a problem with, assertions

it has been asserted that the block of concrete was an intregal part of the original design, i have asked for some documentation to support this claim, to date none have appeared!


it has been asserted that the engineers based the design on moving the center of mass from the engine to within the block of concrete, i have asked for any documentation of this as being fact, even some sort of mention in any book, memoir, anything... to date nothing has
been presented to support this claim!

it has been asserted that the engine will be damage if not mounted to a specific concrete block, again i have asked for some documentation, some mention, some record, newsclip, anything to support this claim, to date nothing!

it has been asserted that the ommission of any word from lister on the use of resilient mounts proves they cannot be used, again some
mention anywhere that supports that they say no dont use them, or any documentation that they tried and failed, how about any mention of anything re. their use or non use?

and on and on.

your side can make assersions,  and speculate on why lister spec'd concrete, fair enough

my side therefore can speculate and make assersions,  as to the viability of using resilient mounts.

my side of the arguement has not taken a rabid stand against concrete, although the same cannot be said for some members of your camp against the use of resilient mounts.

you dont like 'em fine, don't use them. you dont think they will work then provide some form of reasoning other than the original lister engineers didnt mention their use.

bob g

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(useful forums), utterpower.com for all sorts of diy info

SCOTT

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Re: concrete vs resilient mounting
« Reply #44 on: October 07, 2006, 05:30:56 AM »
Procrustes

I will assume you are an intellectually honest person, as such I ask you the following question:

What proof do you require to acknowledge that it is possible to mount a Lister type engine to something other than a cubic yard of concrete? 

Best regards
Scott
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