Wondering what people are doing for crank and main bearings in the LD9 for making a decent amount of power. I began having oil pressure issues and it appears the bearings may be starting to fail. Only 8000kms on the new motor but was hoping it would last a little longer than that. I did have the crank rebalanced but they had to install a .75mm bearing as this wasn't the first time the crank has been rebalanced. So my question is, will a new stock crank hold up better than my rebalanced one or if there is an aftermarket steel one that will handle the stress of the power. Anyways, any insight would be great.
What does balancing the crank have to do with the bearings used?
Where is your oil pressure reading coming from?
What is your pressure?
What other signs are you having?
FU Tuning
The crank bearing is the largest size they could go. So assuming there is a fair amount of material removed from the crank which may have weakened it. Oil pressure was checked from the sending unit and then I installed a oil pressure gauge with a T into the back of the block (which also feeds the turbo). Low oil pressure light had come on (so less than 15psi). Changed the oil and filter and now seems to be running at 20psi after it is warmed up. Cold starts the oil pressure seems ok but once the oil thins out she drops. I also had some metal shavings on the oil drain magnet.
So the crank has been regrinded. You said balanced.
20psi at idle warm is fine. I have had 12psi at idle warm. Oil temp plays a BIG part in oil pressure.
Now that my reading is in the block is usually never gets below 20psi at idle and 200 degree oil temps.
What is your pressure driving and WOT?
some metal shavings can be normal, more so on a newer motor.
When was the last oil change before the one you just did?
FU Tuning
I had handy to 5000kms on the oil when I changed it. Running castrol GTX. I was debating on switching to a castrol synthetic but the car does have small oil leak somewhere (I think its coming from the dip stick tube). I am handy to 40-50psi at higher rpms (gauge does seem to fluctuate a bit but not sure how accurate it is). Cruising at 80km/hr (around 2000rpm) it makes around 25psi. As for the crank, it has been re-ground two times now. Had new bearings installed which were apparently the largest they could go, which kinda tells me the crank was on its last life. Anyways, I'm thinking its only a matter of time for it to come apart. I did put 10w30 in it so maybe I should switch back to the 5w50 (but dont think thats going to have any affect at warm oil temps). Anyways, I was more or less curious to know if there is an aftermarket option that is better or if an OEM crank will do and throw some new bearings in.
For the LD9 OEM crank is all we have, and has made over 500whp.
FU Tuning
I dont think you can really get a better crank than stock without spending alot... i say find a different crank, one with stock specs, get it polished and knife edged while your at it.. swap it with some new bearings. Also check your oil pump while its out.
I had a feeling the crank was going to be good for the power I want to make. I'll get a new one ordered up and hopefully I'll have better luck with a new one. The oil pump is a melling replacement, only 7000kms on it but when its all apart everything will be inspected.
Replace with Clevite 77 bearings... they are one of the highest quality bearings for our motor.
All that work and just a melling replacement pump? i'd go with a 2.3 pump, plan to when I build a motor... i think that'd help alot in the long run as well.
clevite 77's have been proven to well over 500whp in our engines.
if you are really worried have them cryotreated and coated.
I choose the technology built for land speed records... not the technology built to save on emissions and gas mileage.
Jordan wrote:All that work and just a melling replacement pump? i'd go with a 2.3 pump, plan to when I build a motor... i think that'd help alot in the long run as well.
this^
your main failure points of the LD9 block are the oil pump (with balance shafts) that cavatate the oil above 6000 RPM and the stock bearings that like to spin...
2.3 oil pump
clevite 77 bearings
fix both issues.
Edited 1 time(s). Last edited Thursday, June 28, 2012 8:54 AM
I'll get some clevite 77 bearings ordered. I know he put clevite bearings in it when it was rebuilt but not sure what number they were. 2.3 oil pump probably isn't going to happen. I have my reasons, but thanks for the info.
I sent my bearings off for coating to help with bearing life. Shipping both ways and the coating was right around $125.
"Oil Leak ? What oil Leak ? Oh, Thats Just The Sweat From All The HorsePower!!"
if your building an LD9 for power...but dont wanna do the 2.3 oil pump... i see you replacing bearings quite often...facts of life.
scott (section8cav) wrote:if your building an LD9 for power...but dont wanna do the 2.3 oil pump... i see you replacing bearings quite often...facts of life.
this^
the stock oil pump is the reason the number 3 and number 4 rod bearings wear out very quickly...
DSMskyline wrote:I sent my bearings off for coating to help with bearing life. Shipping both ways and the coating was right around $125.
I'll have to look into this. I have heard the srt-4 has a treated crank but I dont think this is necessary for my goals with the car.
So what are people getting for oil pressure at idle, cruising and WOT?
All i have taken measurement of mine is at idle with the engine warm... about 15 psi at the exhaust cam tower.
Edited 2 time(s). Last edited Friday, June 29, 2012 4:29 AM
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scott (section8cav) wrote:if your building an LD9 for power...but dont wanna do the 2.3 oil pump... i see you replacing bearings quite often...facts of life.
I call BS.
First not saying 500hp, but for a 300whp atock is just fine. It has been done on multiple stock oiling systems over the years. In fact one just went 12.2 on a stock bottem end.
I'm still not convinced the poster has a issue.
FU Tuning
Hmm.. I am seeing 20-25psi at idle warm. Maybe I am wrong to think that is not normal. I will take it to work tonight and monitor idle/cruising/WOT pressures and report back. I guess I was thinking I should be seeing 40+ at an idle but I could be wrong with this. Heck if my oil drain plug isn't showing signs of shavings then I may be ok. I just assumed with the pressure I had it was something bearing related.
Has your outside temps been getting warmer recently?
FU Tuning
It is getting a bit warmer here lately. I was doing some looking around and found a page that ha some specs for the motor. Not sure how accurate they are but it claims 10psi minimum at 900rpm and 30 psi minimum at 3000rpm. Took the car to work and I am well above those numbers. About 25psi at idle and 30psi at around 2500 rpm. I'll keep an eye on my pressure gauge and change the oil soon to monitor for shavings.
Well on the way home from work the car seems to be handy to 35psi at 2500rpm. Up around 3000rpm+ its handy to 45psi. Havent ran it high into the upper rpms or at WOT yet so I'll have to get some more numbers someday. For now I am going to keep driving it and keep an eye on things. With only 7000kms on the new motor I would think its just getting broken in.
