this post is for the purest in the group, those that want more info on concrete mounting of the engine

http://www.slideruleera.net/FoundationsForCompressors.pdf

http://www.slideruleera.net/MachineryFoundations.pdf

the first link is particularly interesting when considering concrete as the mount of choice for a compressor or an engine
seems somewhat opposed to that of the lister recommendation, which is not to say lister had it wrong, but

it would appear there is a case to be made for a shallower, but larger in length and width concrete block.
which opens the possibilty of a shallow, relatively large base that would work well with a genset i would think.
coupled with the matting that they refer to, might be the best of both worlds, low vibration, rigidity, safety, and low sound/vibration transmission
isn't that what most folks want?

not trying to stir the hornets nest, but passing along info for those that are so inclined to read it.


bob g

Been doing a bit of thinking and decided to start another thread, actually a two part thread
this coming on the heals of the debate and obvious differences of opinion of what is meant by "efficiency"

first a question presented to the board for consideration and input
with the premise that the lister/oid is an engine and as such is part of a machine,
we cannot fully analize the machine but we can talk about the basic engine, assume consistant fuel, air temp, humidity etc,
only criteria open to chang are with the engine itself, so...

what would i do to increase the efficiency of a lister/oid?
a. get the operating temperature of the coolant up to near 195 degree's F
b. determine that the injection system is atomizing the fuel as well as practically possible
c. set injection timing to proper spec's
d. set valves to proper spec's
e. improve volumetric efficiency, by optimized intake and exhaust runner lengths (possible)
f. reduce internal friction, by proper fitting, finish etc.
g. explore the possibility of reverse flow cooling to equalize temps across the cylinder


what would you do to increase the efficiency of an engine, namely the listeroid?

a. (insert here)


next i would like to discuss the overall efficiency of the machine, which the engine is a part of.

unless one has a view of the machine as an  seperate entity, one has to include himself as part of that machine, in sort
of a symbiotic relationship.
the machine exists to serve us with heat and power, and we need the machine to produce both heat and power.
we don't get heat and power, and the machine does not run if we don't feed it.
we all know that it is far easier to work with mother nature than it is to fight her,

it is very hard for most of us to think of ourselves as a cog in a machine, or not something above or vastly superior.
but that is not the arguement that i am presenting here.

the discussion is one of Efficiency and as such we must step back a moment and see ourselves as part of the machine.

everything we do in life has a cost in "lifeblood" or "life energy" we usually equate it to dollars or yen or rubbles or whatever, but
it is lifeenergy not money.

so where is ole Bob going with all this you may ask?

there is an old adage that goes something to the effect,,," you get 90% of the result with 10% of the effort, and the last 10% result will cost you 90% of the effort"

effort= money= lifeblood= life energy

so if we have a machine that is 90% efficient (remember that the lister was a finely crafted and very efficient engine, that we will have one hell of a time increasing
by any appreciable and measureable amount) and we have invested 10% effort, then it by rule will take an exceptional effort (money, lifeblood, life energy) to increase the efficiency appreciably and measurably. what i mean here is if we assume that a lister engine is 33% efficient making it to 35% is going to take a huge effort, and going beyond that is going to take a monumental effort. remember....

effort= money= lifeblood= life energy

on another post i mentioned the 15 minutes it would take to fuel the example machine, increasing efficiency of the engine while possible would take several magnitudes of effort over what would be gained in less time worked to fuel the engine.

the same amount of time and effort spent improving my employment would have far greater gains returned to me, than investing the time and effort to increase the efficiency  of the engine and by extension the machine.

my point ... i am not advocating setting up a smoking horribly inefficient engine as part of a machine,
what i am advocating is getting the engine and also each component of the machine up to a reasonable standard, to each his own here.

where i part with some is the fight for the last nth of some sort of definition of efficiency ,without factoring in the "life energy" that it will cost.

one can reach a point of diminished returns

thoughts?

bob g

ok .. now to beat a dead horse

i came across something today, and it raised an interesting question

when does a lister/oid become not just an engine but a machine?

if a lister/oid is coupled to a generator, is it now a machine?

if a lister/oid is an engine, what makes it not a machine?

answers to this question is going to be very interesting as it relates to proper mounting
it is late and i don't have the reference with me to quote from, but lets see how folks answer the previous questions, and i will
try and post the reference tomorrow

bob g

something popped into my otherwise overstuffed head today,,
perhaps the definition of resilient mount may have differing meanings to different folks

it occured to me, that while i have an idea of what i would call resilient for mounting a listeroid, perhaps some of
the opposition comes from the more common or classical resilient mount, namely automotive (cars), instead of automotive(hd trucks)

what i have in mind are the type of mounts common to heavy engine's in heavy duty trucks, these mounts are very dense and very rigid, even at several hundred hp, their freedom of movement is vary low at peak torque, ~1/4" or less in some cases, as opposed to automotive (cars) which have freedom of movement of perhaps over an inch when under torque.

i began to wonder if perhaps some of the opposition was based on the idea of using the more common and softer mounts that are used in cars? while i suppose these could be made to work and would provide excellent isolation, "I WOULD NOT USE THEM"

however, i wonder just how much movement one would have with a 6/1 -  25/2  if as i have outline the engine was mounted on a very stiff, concrete filled base that rested on 4 of these hd truck mounts, i would be shocked if the listeroid could deflect the mounts more than a 1/16" at critical speeds, and probably inperceptible at normal speeds and loading. i understand these mounts would not isolate as well as car units, but i would think that it might be a reasonable comprimise, (between rigid and resilient ) giving reasonable isolation.

four of these mounts will easily handle 3k lbs, and can be torqued down to alter their rate of damping.

so i was wondering, how many were thinking that i was going to use soft car type mounts? instead of very stiff mounts?

just wonderiing

bob g

I would like to submit the following for everyone's consideration, this post is not to suggest any
way over another of mounting an engine.  It is basically the most coherent analysis of what has been discussed that I  can come up with. I will try to break it down into components, sometimes simplistic and at other times a bit more complex, in the effort to try and pull the discussion together.

There are two opposing sides at play here, (1) the use of concrete as the only way to mount the engine, and, (2) an alternative method using steel and resilient mounts

In the following paper I will attempt to examine critically both positions, first stating the position
and then examining the position and determine support for that position.

A. "Mr. X  supports the contention that lister only specified concrete as the material of choice for mounting the engine, "

   To date I have seen no documentation as to why the concrete block was to be used, only that it must  be  used to support the warranty.  By documentation I mean supporting engineering text that clearly shows the need for the concrete base, not advertising literature but the math and physic's to support its use. Lacking such documentation one cannot assume whether the use of concrete is mandatory or not from an engineering standpoint.

B. "Mr. X further contends that lister made no recommendation as to the use of anything other than concrete, and specifically that they never mentioned the use of resilient mounts."

   Just as in (A) above I have not seen documentation that lister even tried resilient mounts.
   Again without supporting documentation in engineering terms we cannot assume that the       use of resilient mounts are inherently good or bad.

C. "Mr. X further states that the concrete block was an integral part of the design of the engine"

   Here again to date I have seen no documentation that the concrete block was an integral       part of the engine design. Further anything that is bolted rigidly to the crankcase becomes       part of the crankcase for purposes of transmission of vibration, resonance, and vector       analysis.

   Examining the contention that the concrete block was an integral part of the engine design the engineers in their wisdom would have had to work out all the math/physic's of    a number of parameters all based on the specific use of the concrete base.

   The problem with this contention is the same engine crankcase was also used on the SOM wherein a cast iron base (which bolted to the engine block become part of the crankcase) is used as an intermediary component between engine and concrete block. The use of a cast iron sub frame would require differing physic's, vectors etc. to enable the concrete to still become part of the crankcase. This assumes the contention that the block of concrete was an integral part of the design.

It therefore cannot be an integral part of the design of the engine, because both engines whether mounted directly on concrete or mounted to the concrete via the cast iron base are the same engines, using the same castings.

        So can we assume that the use of concrete as a mounting base is or is not the only way to mount it?  No

        Does it allow room to explore other possibilities of mounting? such as resilient mounts? Yes


Now the opposing side


(D) Mr. Y contends that much has changed technologically in the last 50 odd years

   Mr. Y, needs to understand and accept that while technology has advanced the basic       physics have not changed. Materials in some cases have changed, but cast iron is still cast iron today as
it  was 70 years ago. Resilient mounts while made of better material today follow the same physic's they did back then. Very little is truly new, and practically nothing related to these engines is any different today than it was 50 years ago.


(E) Mr. Y contends that the engine can be mounted on a steel frame with resilient mounts

While anything can be mounted to anything else with sufficient effort, Mr. Y should be aware of the problems he will encounter in doing so. Should the engine be bolted to a substantial steel sub frame with quality components and then bolt the sub frame to the concrete base, technically he should have no problems or safety issues. Basically he will have a steel SOM base. Which arguably may be superior in strength to the original SOM cast iron base.

The problem however arises with the use of resilient mounts and the stresses that will be imparted back not only to the steel sub frame but to the engine block itself. Remember the steel sub frame is now part of the crankcase.

Resilient mount positioning will be critical, and should be in line with the plane of the crankshaft, not below the crankcase as is typically described by those wishing to use this method of mounting.

The question then arises on how to raise the centerline of the mounts to the same plain as the crankshaft centerline? This is where one can get into all sorts of trouble, this is where the highest stresses will be transferred. That being the transmission from the lower frame mounts to the risers. Presumably one would have to weld the frame risers unless he can have the side rails of the steel sub frame mandrel bent to raise the mount to the centerline of the crankshaft. These welds will have significant stresses imparted on them, and over    the course of time will likely fatigue and fail if not properly designed and executed.

Also it is well  worth noting that the engine will exhibit what is known as "critical speeds" which in stationary use the engine should not be running in. These critical speeds are evident when spinning up and down of the engine it passes through rpm ranges where the vibration and stresses are dramatically higher than at rated speed. Provisions have to be made to limit this mode of operation and to provide a measure of additional support for the engine while in the "critical" engine speed range. This adds another layer of complexity to the design.





in conclusion:

there is no clear evidence that the use of concrete is an integral part of the engine design, further there is no evidence that supports that it is the only way to mount it.  Clearly the use of concrete has proven to be a time proven design, a safe design that works. It has proven to not have any detrimental effect on the engine and it could be argued that it has improved longevity of the engine, even though no studies have been done.

The use of a steel sub frame that is securely mounted to the concrete block should provide a safe and sufficient mounting for the engine, that is well within most DIY'ers capabilities.  Also the use of relatively thin and dense pads should cause not adverse effects on either the engine or the safe operation of the engine, although not providing much in the way of abating the transmission of vibration.

The design, manufacture and use of a steel sub frame and resilient mounts should be possible provided that the design is well engineered and fabricated following accepted engineering standards.  It is my conclusion that this may be well beyond the capabilities of the average DIY'er.


   My hope in presenting this thread/post/paper is to cut through the feeling, thoughts and conjecture that has been prevalent in the discussion, and to narrow it to the basics at hand.
Again I am not going to suggest one method of mounting and engine over another. Should the end user of an engine not feel he understands fully the forces at play I would strongly suggest the use of either concrete direct mounting or a steel sub frame directly mounted to the concrete.

hopefully this will be accepted by all in the spirit it was written
I invite constructive criticism, thoughts and questions, and of course opposing views 

bob g

just wondered if anyone is or has thought of building a trigenerator, ie, electricity, heat and refrigeration?

bob g

been reading thru the thread on problems and there seems to be some concern over the number of serious failures
such as broken camshafts

the number was bantered about as being 2 out of 500 as being unacceptable
that is 0.4% failure rate.

some prespective

the target comeback rate in a heavy duty diesel shop is not to exceed 3%

big truck gear box rebuilt shop industry standard is 3%

a journey level hd truck mechanic, will often have over 3%, but will offset the losses with time gains elsewhere.
the more gains he has the more comeback the shop will tolerate.

25 years ago, if you owned a new cummins of 335 hp or over , the odds of a broken crankshaft were over 20% in the first 100,000 miles, (typical mileage a truck travels in one year)

i could go on but you get the point

also,, you have to figure that the 456 members of this board are not a scientific cross section of listeroid users, but rather a group of folks that range from those that have problems, tire kickers, wannabee's, and never gonna be's

bottom line is this,,, the listeroid is a sound engine, with a few issues in some cases that are troublesome, in some cases require some work to sort out, and in most cases  easily rectified.

if you do a cost/benefit ratio,, cost per hour, time running to time worked on,, how ever you want to analylize it they are still the best thing going for 99% of those using them.

as for the analysis, i spent 10 years defining my need, and refining the numbers, then putting it away and then refigureing with fresh eyes. this was long before the lister was even known to me.

i then bought one,, although i had heard from george the problems associated with it. i have had it in a crate that it came in months ago.  i have reevaluated the engine time and time again, and to be honest i liked the changfa better for my needs.

in the process of rethinking the lister, working thru the problems in my own mind, i have come to the conclusion that it is a very viable engine.

i would invite anyone to debate me on this one, so far no one has talked me out of or persuaded me otherwise.

i have the changfa's, a pair for each need, one to use and one as a backup, and countless other engines,, and only one listeroid.

i guess everyone has their own outlook on life based on their life experieces.  i dont know what perfect world some folks live in, where less than a 0.4% failure rate exists, but it surely is not anywhere near the reality with diesel engines in this country in my experience.

perhaps if i was an aerospace engineer, i would take a very long down my nose look at these engines, and scoff

or if i was a rolex technician,, i would take a dim view of them as well.

but that aint my perfect world and likely it isnt the perfect world for 99% of us.

besides there is no alternative, none, nada,,, zero

just some perspective, at a time it seems to be needed around here.

bob g