RAB:
sorry i missed your earlier responce to my post, my puter took a dump and is in the shop
and therefore i am using my daughters laptop and missed a day or two.
anyway, i am sorry i blew your dress up around your neck
i will defer to those with vastly more experience with the original listers, and maybe that includes you on
certain points,,, however
i will not simply roll over and play dead when it comes to a few points,
one being the need for oil splash to cool the piston, this is a concern with every internal combustion engine that
was ever made (at least the ones that were successful)
the original poster talked of the engine becoming tighter after it had been run and voiced concern whether there was
sufficient piston to bore clearance.
i think we can assume that the oem made the bore near perfect as well as the piston being properly sized as well, so
if it is getting tight when hot is a good indication that there is some fault with cooling allowing the piston to overgrow the
oem clearance spec.
i am not suggesting that this is the only possible reason for the engine getting tighter, only mentioned one area that might be
investigated to eliminate that possible cause. surely there are other area's that should be checked first, things like timeing issues, injector spray, fuel type etc etc.
as for splash lube, yes i know it works on many engines, and has been successful, but
to my knowlege the method that lister used was somewhat unique as it relates to big end oiling.
yes the system worked well with the oem setup, which includes the oils they spec'd, the fuels they spec'd, the load
that it was rated for, "and" the original metallurgy of the big end brgs (metallurgy which has changed over the years)
the primary reason i don't like the oem oiling system for the big end is based on the experience of those running listeroids
which use the same oem design, but modern brgs metallurgy, modern oils, and fuels,, and it does not work as it did on the originals!
i have seen many examples of the top shells being beaten to death and needing replacment far sooner than i would expect
the oem lister ever required.
if you were to do a bit of study on proper big end oiling, the need for establishing a hyd wedge (and maintaining it) it becomes
apparent that those two top feed holes and their accompanied grooves destroy the wedge that is formed which in turn shortens
the brg life.
many years ago the cummins small cam engines used to use a top hole to provide oil through a rifling to the wrist pin, those
brg needed replacement every 75k miles (if english origin) or 150k miles (if japanese origin). cummins found that the placement of this hole was in line with the peak cylinder pressure and caused a breakdown of the hydraulic wedge,, effectively beating the top shell to the point of delamintation of the brg. In the late 70's they changed the design and moved the rifle hole offset about 30 degrees with the result being brgs that lasted twice as long with no other changes being made. later they found in the big cam1 or maybe bigcam2 engines the change in the hole location allowed them to reduce the oil pressure from 60psi hot to ~30psi hot without loss of brg longevity.
engineering text goes into much detail on not putting any holes in the top shell near the top where cylinder pressure is high, and not to put any grooves in the brg at all.
i know this works, i have seen it. i also know of a supplier in canada that special ordered some brgs for his engines that had no holes or grooves and installed them with a hollow dipper. the result has been a dramatically improvment in the longevity of his engines and he runs them very hard in continuous duty running waste veggie oil.
as for piston cooling, there must be some oil being thrown up under the piston to aid in cooling, maybe not much for a 3/1 and maybe even not much for a 6/1 on moderate loads,, but
if he has some coking under the head of the piston he has a problem, and therefore he needs to explore and find the reason why
this is happening. if there is sufficient oil up there it will cool the piston and not coke, even if he is running advanced timing, overfueling or running some hot fuel mix. certainly if the timeing is off, running under heavy loads, hot fuel, etc. he will need more oil splash to cool the piston.
i only offered one possible area to look into that being is the oil level sufficient to be picked up and sprayed up under the piston,
i did not suggest this as the only possible answer, just simply one that can easily be checked. i would not want to hear back later that
the engine was made up of various parts (unknown to him) that might not be as you or i suspect, and therefore be lower on oil than it should be. i think i mentioned earlier about a friend with a twin petteroid that filled the new engine to the full mark, and later found that the engine was about 2 quarts low (after removing the side cover and finding the oil pump pickup tube only partially submerged) because the dipstick was from another type of petter or was marked wrong.
sometimes it is the stupid details we just assume to be correct that come back to cause us the most grief.
to conclude
if i had an original lister, and original lister brgs, running a non detergent oil of the proper weight i like you would just run it.
however here in the states original listers are like finding a 53 corvette with 100 original miles locked in some old ladies barn!
we gotta live with listeroids and as such have to accept that there are improvments that can and in my opinion should be done
to improve the longevity of the engine.
also i have been around for a very long time and know a thing or two about diesel engines in general, and proper engineering practice in particular.
btw,, i still don't like the oem tophole fed big end brg design, even if it has proven sucessful!
as i am sure there are things you don't like about some other engine design.
bob g
