Rod And Main Bearings Shrank

[darren lewis]

Ok first of all, the oil starvation is the most likely cause but it still doesn't tell you why it failed.

The oil pump/restrictor/head return is a crock of shit. Nissan don't have issues with any of that shit. Yes, improvements can be made to the system but at 3k on a fresh engine, it's still a crock of shit.

The ONLY time oil control is an issue is if it's an RB26 without sump modifications AND it's on a race track at the time of failure.

3k old engine, so it's likely to be only just finished the run in. The fault can be anything from abuse during run in, to incorrect assembly.

And I don't see how any of you other engine builders can pretend to know the cause while only looking at one single BE cap. The picture quality is too poor and it's only one cap.

It doesn't matter how many pictures this guy puts up, without inspecting every single piece of the puzzle in detail, you are all just guessing.

gee you guys make it hard for the guy to try find out the cause, i have stated what caused the bearing issue whether he wants to take that advice or not is entirely up to him. we have been building and developing the rb engine over 4 years of drift and track use that linked with our 30 years of engine building experience we should be able to hit the nail on the head . do you think? to pick YOURE reply apart

1, you state ' oil starvation is the most likely cause' so why do you state that 'doesnt tell you why it failed' when the oil starvation is WHY it failed.

2 'nissan dont have any issues with that shit' nissan designed it to produce 150rwkw not double that. the GTR was developed by the factory 200 odd rwkw and all upgrades were done at the factory to accomodate the GTR power level.

3whether race track or street no different. a car can be driven on street with as much punishment as on track

4if the engine is built and tuned correctly it will need no RUN IN maybe if it was a t model ford engine it will need run in.

5how can there be 'abuse during run in' the thing should be built properly , tuned properly then driven how it was built for . built for 8000rpmall the time ABUSE???

6 we can tell what caused it by looking at one bearing cap as that is what we do , build an engine , develop it ,look at internal parts , address the problems. then offer the customer a developed package ,no guess work or learning with their money....

7 the picture is good enough quality and if one cap is like that all will be.

needing. oil drain rear of head, 1.2 mm oil restrictors, hi vol sump, 2.5 litre catch can with drain back to sump, max oil pressure of 70 psi @8000rpm,redline 50w race oil THAT WILL FIX IT with correct bearing clearance, following up with knowledgable tuner .

the jun pump is designed for an rb26 way too much oil pressure on others needs to have oil pressure relief valve modded to reduce pressure. as the relief valve is in the sump you need to get it right on the build. this is why we like to use the tomeii pump with external reg.

[The Dan]

gee you guys make it hard for the guy to try find out the cause, i have stated what caused the bearing issue whether he wants to take that advice or not is entirely up to him. we have been building and developing the rb engine over 4 years of drift and track use that linked with our 30 years of engine building experience we should be able to hit the nail on the head . do you think? to pick YOURE reply apart

1, you state ' oil starvation is the most likely cause' so why do you state that 'doesnt tell you why it failed' when the oil starvation is WHY it failed.

2 'nissan dont have any issues with that shit' nissan designed it to produce 150rwkw not double that. the GTR was developed by the factory 200 odd rwkw and all upgrades were done at the factory to accomodate the GTR power level.

3whether race track or street no different. a car can be driven on street with as much punishment as on track

4if the engine is built and tuned correctly it will need no RUN IN maybe if it was a t model ford engine it will need run in.

5how can there be 'abuse during run in' the thing should be built properly , tuned properly then driven how it was built for . built for 8000rpmall the time ABUSE???

6 we can tell what caused it by looking at one bearing cap as that is what we do , build an engine , develop it ,look at internal parts , address the problems. then offer the customer a developed package ,no guess work or learning with their money....

7 the picture is good enough quality and if one cap is like that all will be.

needing. oil drain rear of head, 1.2 mm oil restrictors, hi vol sump, 2.5 litre catch can with drain back to sump, max oil pressure of 70 psi @8000rpm,redline 50w race oil THAT WILL FIX IT with correct bearing clearance, following up with knowledgable tuner .

the jun pump is designed for an rb26 way too much oil pressure on others needs to have oil pressure relief valve modded to reduce pressure. as the relief valve is in the sump you need to get it right on the build. this is why we like to use the tomeii pump with external reg.

That is disappointing coming from you.

I will address your post later this evening when I have more time to correct you.

[T04GTR]

ok. just for refferance here.. on a standard rb26 no oil restrictors and stock turbos ie: not much power

i installed a mechanical oil pressure guage and on a straight flat road, with the oil level on the high mark,

from a standing start (fast take off but not a launch) the oil pressure was surging the whole way thru first gear and partly in second..... and this was a 220-240rwkw gtr.

it took an extral 800ml to stop it surging in first gear...

so if you have good power without any sump mods. (tomie bafle does nothing on acceleration) you will have been surging. so if this is so, your engine would of been ingesting foamed up oil.... not no oil, but badly airated oil.

and yes. seeing it all is the only way to tell.

but if the bearings are all the same, im guessing its an assembly/start up fault.

if the bearings are worst on 1 and 6 bad on 2 and 5 and ok on 3 and 4 (see the pattern) its oil starvation.

if its the opposite or just one or 2 like that with the nearest main bearing also dammaged its dirt..

my guess anyway. need to see all the bits..

[Swiper the Fox]

if its the opposite or just one or 2 like that with the nearest main bearing also dammaged its dirt..

ok blame me...its ok

[The Dan]

gee you guys make it hard for the guy to try find out the cause, i have stated what caused the bearing issue whether he wants to take that advice or not is entirely up to him. we have been building and developing the rb engine over 4 years of drift and track use that linked with our 30 years of engine building experience we should be able to hit the nail on the head . do you think? to pick YOURE reply apart

1, you state ' oil starvation is the most likely cause' so why do you state that 'doesnt tell you why it failed' when the oil starvation is WHY it failed.

2 'nissan dont have any issues with that shit' nissan designed it to produce 150rwkw not double that. the GTR was developed by the factory 200 odd rwkw and all upgrades were done at the factory to accomodate the GTR power level.

3whether race track or street no different. a car can be driven on street with as much punishment as on track

4if the engine is built and tuned correctly it will need no RUN IN maybe if it was a t model ford engine it will need run in.

5how can there be 'abuse during run in' the thing should be built properly , tuned properly then driven how it was built for . built for 8000rpmall the time ABUSE???

6 we can tell what caused it by looking at one bearing cap as that is what we do , build an engine , develop it ,look at internal parts , address the problems. then offer the customer a developed package ,no guess work or learning with their money....

7 the picture is good enough quality and if one cap is like that all will be.

needing. oil drain rear of head, 1.2 mm oil restrictors, hi vol sump, 2.5 litre catch can with drain back to sump, max oil pressure of 70 psi @8000rpm,redline 50w race oil THAT WILL FIX IT with correct bearing clearance, following up with knowledgable tuner .

the jun pump is designed for an rb26 way too much oil pressure on others needs to have oil pressure relief valve modded to reduce pressure. as the relief valve is in the sump you need to get it right on the build. this is why we like to use the tomeii pump with external reg.

I understand you have 30 odd years experience which is why I don't understand how you can claim to know how EXACTLY his engine failed without seeing every part.

There are so many scenarios for how an engine can fail and several of them will net the same result on the big end bearings.

I said that oil starvation does not tell you why it failed because there are also several reasons why a bearing can be starved of oil. Not just one. You claimed to know the exact reason without doubt.

Knowing that one bearing was starved of oil is easy, know why it was starved of oil is not without seeing the whole package. And even then, you'll need information from the owner of the car to know exactly what he/she was doing at the time of failure so you can base your judgement on the evidence.

The reason why I said Nissan don't have issues with it is because they don't. There GTST's have never had inherit problems with oil control. Their GTR's have not. I will admit the GTR is probably the worst candidate as the drain back holes from the rear of the sump are too small to allow fast flow back and, therefore, capture the oil at the back of the sump instead of allowing it to return to the pickup area. This is a simple fix.

Just because he is making double the HP from factory, doesn't mean he requires double the oil does it? 150kw or 300kw, at 8000rpm he's going to require the same amount of oil to lubricate the system so your point on HP is incorrect.

He may be able to drive the car on the street with as much enthusiasm as on the track but we live in the real world here and obviously he wouldn't be so confused as to why his engine failed and I don't recall seeing him on the 6o'clock news.

Your point on RUN IN is also incorrect. Are you trying to tell me that the rings just magically seat into the bores? are you trying to say the bearings have absolutely no bed in period?

I'll pay you to build an engine, put it in my car - but don't start it. Let me take the car away without running it in. I'll take it out onto the street in front of your place and let it sit there at idle for an hour and a half. We'll see how long it takes for your engine to start pumping smoke.

Even the first 20 minutes where you start it up and give it some revs while you might be checking for oil or water leaks etc. That is a run in of sorts.

8000rpm does not mean an engine is being abused. There are plenty of ways to abuse an engine without getting it anywhere near 8000rpm.

Yes you do build good engines, and have been building them for many years but don't claim to know how this guys engine failed by looking at one bearing cap. You can assume what happened but not clearly identify the cause of failure. You are giving him false hope. Even though your reason may very well be the cause, there are still dozens of other reasons that may go unaddressed.

The factory RB25 pump flows enough oil to run pressures above 80psi. In fact, 90 and 100 psi on a new one. I've built engines with most aftermarket options and it doesn't matter if it's a JUN pump, Tomei pump, N1 or factory pump, they'll all pump good oil, and with proper clearances etc, the pressure is always around the same give or take 10psi.

You say there is no guesswork or learning so this means you know absolutely every single thing there is to know about an RB engine. Which is why I am so shocked to read your last comment:

"the picture is good enough quality and if one cap is like that all will be."

THAT is why I said I am disappointed that came from you. Some engine failures are simple and yes, all the bearing caps will look similar but not the same, close enough I guess. But plenty of times you'll get an engine come in that is not so simple. Something has gone wrong that isn't just a simple fix or simple explanation. What if someone built an engine and there was a grain of sand stuck under the main girdle on one cap between the parting faces. It only got stuck there after all the measurements were taken so it could not have been identified by having a clearance issue. We'll assume the owner of the car has built this engine. I wouldn't expect any decent engine builder to have this issue of course as everything is clean on assembly.

The clearance on 3 caps either side of this and the cap in question will have excessive clearance. The engine will still run, it will still have oil pressure, but drive the car for one or two weeks and the main bearings slowly start to wear out. They get worse and worse and finally they are bad enough to effect the oil pressure. Because the main galleries feed the big end galleries, a drop in pressure on the mains is a drop in pressure across the big ends. The engine starts to rattle ONLY when the big ends have failed. The main bearings are all f**ked by this point in time but they have starved the oil to the big ends. The engine is pulled down. The guy who owns the car takes a photo of one of the big end bearings in it's respective cap and Mr Lewis says to him, "This engine has failed due to oil starvation". That is correct. It has failed due to oil starvation. The customer says "ok, so how do we stop it from happening again?". Mr Lewis says "Modify your sump and put in restrictors and extra head returns because you were cornering at 3 times the legal speed limit, cutting across two lanes at 3G's". The customer says "but I was driving in a straight line and I live in the Northern Territory, and the only road I drive on is that big long son-of-a-bitch that goes down the guts. It's never turned a corner in the 500km's it has driven."

I don't really care if you have 200yrs engine building experience

YOU CANNOT IDENTIFY THE CAUSE OF HIS ENGINE FAILURE BY LOOKING AT ONE CAP

[T04GTR]

awwwwwwwww. megga post

[T04GTR]

yes. all tru. but lining up all the caps in order will identify what sort or issue is at heart.. agreed?

[SLAPS]

3lit3 32,

You've missed the critical 'modification'.

A JUN pump with std restrictors. The car has been tuned as such it has seen high rpm.

Given a Jun pump was fitted without oil restrictors it sounds like a half arsed build.

Mine with close a little over 90psi >4000rpm prior to restrictors and tuning up over 5000rpm it was filling the covers to the point where I could see the cam lobes working well 'under' the oil with the level touching the filler cap as it screwed in, yes on the dyno oil pressure was showing signs of slight surge and that was stationary. :S

Head off restrictors fitted and zero drama's since then on.

My bet is the car was tuned then given a little hiding on the street, its surged and she's popped.

Regardless it needs to be built again with the oiling problems these motors have addressed.

Make sure the block is cleaned properly, bottom end line bored and clearances spot on.

Edited February 7, 2009 by TheRogue

[MrStabby]

The reason why I said Nissan don't have issues with it is because they don't. There GTST's have never had inherit problems with oil control. Their GTR's have not. I will admit the GTR is probably the worst candidate as the drain back holes from the rear of the sump are too small to allow fast flow back and, therefore, capture the oil at the back of the sump instead of allowing it to return to the pickup area. This is a simple fix.

Can you clarify/rephrase this? You say there's no problem with GTSTs and GTRs but then you say the drain holes on the GTR are too small.

Also, can you comment on T04GTRs evidence - "from a standing start (fast take off but not a launch) the oil pressure was surging the whole way thru first gear and partly in second..... and this was a 220-240rwkw gtr. "?

Cheers

[STATUS]

Sory, its the camera flash.

Bearings ran close 3k mileage.

No restrictors. Problem is, i dont have a catch can.

Oil pump was JUN. Bought new. HKS oil cooler and Motul oils.

This is just crap!

I just wanna find out the cause of it. Least i know whats the problem now..

Do you have a oil cooler with a thermostat in it? i have now seen 2 cars (owner built and installed) lose engines due to incorrect hookup of the remote mount and cooler, oil pressure is fine until the oil reaches temp then the thermostat opens and bang no oil pressure or minimal pressure. Proved with a pressure gauge on both occasions to unbelievers.

Make sure the lines are all running in the correct direction, oil flows into the engine through the oil filter thread and into the filter from off the the side of the filter thread... many think oil comes out of threaded section on the block then into the centre of the filter.

[darren lewis]

I understand you have 30 odd years experience which is why I don't understand how you can claim to know how EXACTLY his engine failed without seeing every part.

There are so many scenarios for how an engine can fail and several of them will net the same result on the big end bearings.

I said that oil starvation does not tell you why it failed because there are also several reasons why a bearing can be starved of oil. Not just one. You claimed to know the exact reason without doubt.

Knowing that one bearing was starved of oil is easy, know why it was starved of oil is not without seeing the whole package. And even then, you'll need information from the owner of the car to know exactly what he/she was doing at the time of failure so you can base your judgement on the evidence.

The reason why I said Nissan don't have issues with it is because they don't. There GTST's have never had inherit problems with oil control. Their GTR's have not. I will admit the GTR is probably the worst candidate as the drain back holes from the rear of the sump are too small to allow fast flow back and, therefore, capture the oil at the back of the sump instead of allowing it to return to the pickup area. This is a simple fix.

Just because he is making double the HP from factory, doesn't mean he requires double the oil does it? 150kw or 300kw, at 8000rpm he's going to require the same amount of oil to lubricate the system so your point on HP is incorrect.

He may be able to drive the car on the street with as much enthusiasm as on the track but we live in the real world here and obviously he wouldn't be so confused as to why his engine failed and I don't recall seeing him on the 6o'clock news.

Your point on RUN IN is also incorrect. Are you trying to tell me that the rings just magically seat into the bores? are you trying to say the bearings have absolutely no bed in period?

I'll pay you to build an engine, put it in my car - but don't start it. Let me take the car away without running it in. I'll take it out onto the street in front of your place and let it sit there at idle for an hour and a half. We'll see how long it takes for your engine to start pumping smoke.

Even the first 20 minutes where you start it up and give it some revs while you might be checking for oil or water leaks etc. That is a run in of sorts.

8000rpm does not mean an engine is being abused. There are plenty of ways to abuse an engine without getting it anywhere near 8000rpm.

Yes you do build good engines, and have been building them for many years but don't claim to know how this guys engine failed by looking at one bearing cap. You can assume what happened but not clearly identify the cause of failure. You are giving him false hope. Even though your reason may very well be the cause, there are still dozens of other reasons that may go unaddressed.

The factory RB25 pump flows enough oil to run pressures above 80psi. In fact, 90 and 100 psi on a new one. I've built engines with most aftermarket options and it doesn't matter if it's a JUN pump, Tomei pump, N1 or factory pump, they'll all pump good oil, and with proper clearances etc, the pressure is always around the same give or take 10psi.

You say there is no guesswork or learning so this means you know absolutely every single thing there is to know about an RB engine. Which is why I am so shocked to read your last comment:

"the picture is good enough quality and if one cap is like that all will be."

THAT is why I said I am disappointed that came from you. Some engine failures are simple and yes, all the bearing caps will look similar but not the same, close enough I guess. But plenty of times you'll get an engine come in that is not so simple. Something has gone wrong that isn't just a simple fix or simple explanation. What if someone built an engine and there was a grain of sand stuck under the main girdle on one cap between the parting faces. It only got stuck there after all the measurements were taken so it could not have been identified by having a clearance issue. We'll assume the owner of the car has built this engine. I wouldn't expect any decent engine builder to have this issue of course as everything is clean on assembly.

The clearance on 3 caps either side of this and the cap in question will have excessive clearance. The engine will still run, it will still have oil pressure, but drive the car for one or two weeks and the main bearings slowly start to wear out. They get worse and worse and finally they are bad enough to effect the oil pressure. Because the main galleries feed the big end galleries, a drop in pressure on the mains is a drop in pressure across the big ends. The engine starts to rattle ONLY when the big ends have failed. The main bearings are all f**ked by this point in time but they have starved the oil to the big ends. The engine is pulled down. The guy who owns the car takes a photo of one of the big end bearings in it's respective cap and Mr Lewis says to him, "This engine has failed due to oil starvation". That is correct. It has failed due to oil starvation. The customer says "ok, so how do we stop it from happening again?". Mr Lewis says "Modify your sump and put in restrictors and extra head returns because you were cornering at 3 times the legal speed limit, cutting across two lanes at 3G's". The customer says "but I was driving in a straight line and I live in the Northern Territory, and the only road I drive on is that big long son-of-a-bitch that goes down the guts. It's never turned a corner in the 500km's it has driven."

I don't really care if you have 200yrs engine building experience

YOU CANNOT IDENTIFY THE CAUSE OF HIS ENGINE FAILURE BY LOOKING AT ONE CAP

wow , you should work as a legal representative , they talk in circles and never get to a solution?????

meanwhile off the topic and still no constructive reasoning to his question. by for ,, past my patience threshhold !!!!!!!!!!!!1

[Drift Motorsport]

blitz.......... less crap talk and more pics and info on the setup and oil related issues.

Trent, here's a picture to confirm the oil flow: