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so far this racing season, I've had 4 engines fail. all have spun rod bearings (#2 or #3). all specs were perfect on build. 2 different people built the engines. all but one had balance shafts removed. all had 80psi oil pressure @ 7000rpm. all engines balanced except one with balance shafts. all had 50-60psi oil pressure hot at idle.

before I blow up #5, what are we missing. Cranks are cross drilled. This is getting very frustrating. I had crank scrapers on 3 of the engines.

22dodge wrote:before I blow up #5, what are we missing.

Do you have a sump baffle and/or oil accumulator?

Cheers.

yes the pan is baffled, crank scraper on 3 of the engines, we are not allowed to run an oil accumulator.

what viscosity and type of oil?
what oil pump are you running?

do you run sustained high RPM? maybe add a head drain pipe to get more oil from the head back to the sump quicker.

using 20w50. air temp has been 28-32°C water temp never over 85°c stock oil pump. balance shaft elimination kit on 3 of the 4 engines. oil pressure good even after it started knocking

just pin the bearing caps and drill the bearing for the pin as done with alloy rods

22dodge wrote:using 20w50. air temp has been 28-32°C water temp never over 85°c stock oil pump. balance shaft elimination kit on 3 of the 4 engines. oil pressure good even after it started knocking

what clearances are you running when you build the engines?
I would probably run a 15-40 or 10-30 if they're on the tighter side of stock.

also, are you running a 10 or 12mm pump?
you might be getting oil airation from the sound of it.

.0015" rods
.0025" mains


and 3 cranks are bent

3 are spun #2
1is spun #3

IDK what a 10mm vs 12mm on the oil pump.

damn, youve got something funky going on there.
how much power are you putting out?
are you sure its not detonating and just hammering the bearings?
how well is it balanced?
how long between failures?

i built mine to .0020" rods and .0025" mains. and run a 15-40 synthetic oil.

as for the oil pumps theres 2 types, depending on the origin of the engine. can be seen here > http://www.sigma-galant.com/viewtopic.p ... ear#p14861

also the sumps we have available here in aus are different, i run a slightly modified FWD sump as theres way more baffling and its deeper and holds more.
ive heard of people running a tube from the head to the sump to drain the oil back quicker, as at very high rpm it can pool in the head and lead to it picking up air.
where the mech fuel pump would go, maybe you should run a 3/4" hose down to the sump for oil scavenging.

do you use a oil restrictor to the head? .083" ,restrict the oil flow to the head and install a return line from head to sump thats 5/8 dia min
also a good idea to use a custom sump that hold no less than 5lts of oil but 8 is better
and are you block the oil feeds the the balances shafts correctly ? i know its silly but !
what side clearance do you run on the rods?
cheers stealth

After reading this the only other thing I can think of is what do the other non spun bearing look like? how black is the rod with the spun bearing? What bearing you using?

Cheers

there is a definite appearance of oil starvation on the bearings. #2 is the worst and obviously seized to the crank and spun.

I never did like the oil pump on this engine. When I look at the engineering the pump is spinning faster than the crank. I'm going to have to see about the forklift pump/chain drive.

I'm thinking the oil pump has cavitation spinning so fast. (engine rpm is running 6500-7000).

I just got my engine back from the machine shop. I'm going to install an oil restrictor to the head (.120"), and I'm going to use Shaffer synthetic oil 10w30. synthetics are less likely to foam/cavitate

every engine that has failed me due to low oil has spun bearing number 4 up the back. i looked at the oil flow and that bearing is the last to recieve its oil, so on low pressure, that'd be the first to fail. . i wonder why yours is 2 and 3?? i doubt it, but it might have something to do with it???

I think #2 is failing because it's the closest to the filter and if foamy oil (aerated) the air is hitting #2 with the most foam. This is pure speculation but my theory has some logic. I'll see how this weekend goes with an oil restrictor to the head, synthetic oil and a lighter weight.

I really appreciate the forklift oiling system tips/link. I'm having a tough time finding the parts locally. Tomorrow, I'm stopping at a forklift parts dealer to see if I can get the pump and drive chain/gears

good luck

well, just put in engine #5 and it didn't even make 20 seconds. as soon as it started, the oil pressure spiked over 150psi and blew the oil filter apart before I could even shut off the engine. Brand new pump. I'm about ready to junk the 2.6 and make a 2.2 Chrysler engine work in this car.

Ouch man.

sounds like the pressure relief on the oil pump is jammed.

Are you allowed to use a remote oil filter/cooler?
If yes, I'd run large hoses too and from the remote oil filter/cooler, they would act a bit like an oil accumulator, along with 2 x 5lb non return valves, so the excess oil doesn't drain back into the sump.
Also, put a 1/4" bleed line (with a 1/16" restriction) at the highest point of the hose and dump it back into the sump.
The large hoses will slow the speed of the oil down, allowing the air more time to come out of the oil and then the bleed line, if placed at the highest point, will dump the air and a bit of oil, back into the sump.

I use one of these Pure Power Stainless steel oil filter, they filter the oil better than a standard paper filter (around 35microns) and you can see if there is any debris being picked up by the pump.
They also won't split open if the oil pressure gets a bit high.

Cheers.

well, so far engine 5 is surviving. I modified the pan to 7 quarts. and I'm running 10w30 synthetic oil. Now I need more Hp. I need a M9 head.

Its a fairly common problem if your using the factory oil pump. I seen it a number times in a curcuit racing enviroment.

Engine makes 70-80psi of pressure with no Lateral load on the car, but then drops to 10-20psi once lateral load is applied to the car........ and boom, dead engine!
There is a special factory competiton oil pump...... pumps twice the amount of oil and turns at half the speed of the standard factory pump.

I have one in my motor and have never had a pressure problem using a standard pan and standard oil capacity (4.5l from memory), but good luck finding one.

I believe some of the Canter truck engine's may use the same pump, as well.

I found I want a Forklift oil pump and drive. it turns slower and has more volume. so far the last engine is working. I built a 6qt oil pan, put an oil restrictor to the the head (.120") and running top quality synthetic oil.

Now I need more HP. and the only way to achieve that is with more compression. I NEED a Magna TS M9 cylinder head!!!!!!

BIG26L wrote:Its a fairly common problem if your using the factory oil pump. I seen it a number times in a curcuit racing enviroment.

Engine makes 70-80psi of pressure with no Lateral load on the car, but then drops to 10-20psi once lateral load is applied to the car........ and boom, dead engine!
There is a special factory competiton oil pump...... pumps twice the amount of oil and turns at half the speed of the standard factory pump.

strangly enough I use a std ( preped )early model pump in my circuit car with not problems
I have only run 1 bearing found to be a faulty pump near on 10 years ago at Phillip Island

I use a good oil penrite hpr40 oil presure 65 psi - drops to 35 at idle hot and the engine runs most of its life between 4000 and 7000 + rpm

there is no reason that a pump that pumps 70 - 80 psi in a straight line should do any thing different in a corner
the reason is that the sump is a bad design - not baffled properly and not big enough
the pump drops presure as there is no or little oil at the pick up in the corner
the astron doesn't return oil to the sump fast enough at higher revs so a high vol pump is even worse by emptying the sump faster

I have even thought about blocking the rear oil drain back hole in the head so that the oil would only flow down the front in the timing cover
or after blocking the drain doing a big return from the unused fuel pump hole and directing the oil to the front of the sump
my reasoning here is that droping oil into high speed air ( around the crank ) is both a slow way to try and return oil to the sump it is also heating the oil as well and worse slowing the engine due drag

22dodge wrote: I'm going to have to see about the forklift pump/chain drive.

I'm thinking the oil pump has cavitation spinning so fast. (engine rpm is running 6500-7000).

I just got my engine back from the machine shop. I'm going to install an oil restrictor to the head (.120"), and I'm going to use Shaffer synthetic oil 10w30. synthetics are less likely to foam/cavitate

Good move with the fork pump, they also run a 60psi spring, 60 is all you need in these engines.
at 80psi with the std pump or a magna pump would be spiting a lot of oil out the front of the pump and back to the sump, That may be helping to suck the sump a little more dry in the corners, Like cheater said its not getting back to the sump fast enough.
I run fork pumps, Or tho it may not be needed you defiantly cant go wrong using one.

Now if I could have someone help me find a M9 closed chamber head, I might have a chance to make some serious power.

M8 is closed also, There were heaps at pick a part last time i walked thru, I have one im porting atm, be interesting to see how it performs,.

22dodge wrote:Now if I could have someone help me find a M9 closed chamber head, I might have a chance to make some serious power.

I've got a clean non cracked M9 at my shop for sale, a USA starquestclub member wanted it but i havnt heard anything for ages from him..

PM sent to redzone


as for M8, I keep getting conflicting stories about them being open or closed chamber. but the consensus is all m9's are.

if you ask for a picture before buying, it should be easy enough to find one

Rallyant wrote:M8 is closed also, There were heaps at pick a part last time i walked thru, I have one im porting atm, be interesting to see how it performs,.

Hey glen
is this for the Cheater beater ? are you sliding in some larger valves as well

22dodge wrote:PM sent to redzone


as for M8, I keep getting conflicting stories about them being open or closed chamber. but the consensus is all m9's are.

M6 and 7 are open ------- M8 or 9 are both closed chambers

cheaterparts wrote: Hey glen
is this for the Cheater beater ? are you sliding in some larger valves as well

Indeed it is! Yes those larger Ti valves will be sliding in, once spun down to size. Lots of de shrouding to do in the combustion chamber.
Hows your cheater beater, beater engine build going?