Bill

adrial,

Agree.

KISS - install a new mechanical oil gauge (could be temp/could be perm). If corrected, congragulations. If symptom continues, forget the electrical system and move to the oil system.

Test....Test....Test...Fix

smokey

Dave E, you mention that both your current car and your previous car had a 1/2 bar drop in oil pressure at full throttle on the track. If this was a gradual drop as the oil got hot down the length of the straight, this is normal - but undesirable. When I had 240 hp, my oil pressure never dropped below 4 bar on the track. When I got to about 290 hp, the oil pressure dropped to 3.5 or even 3, and this is too low. The rule of thumb is 10 psi per 1,000 rpm, so at 6,000 rpm you want to be at 4 bar minimum. In my experience, limited to one car, the stock 951 oil cooler is inadequate on the track above 250 hp. Horsepower equals heat. I installed a larger oil cooler, and my problem is solved. Oil pressure never drops below 4 bar. From the look of your engine upgrades, you may want to look into some more oil cooling to provide extra protection for your rod bearings. What's your oil pressure on long left-handers?

Dave E

Uhhh, lighten up Bill, I wasn't going to hold anyone hostage over their reply, John was confusing and I only wanted clarification on an issue he might have had experience with. I'm actually fairly skilled in mechanics, but just thought I'd throw this weird oil issue out there for comment, I hadn't gotten to the point of trying to fix it yet, just asking if other folks had seen this with their cars...Smokey, I have a big honkin' Earl's cooler plumbed in series(12an) with the stock cooler(which I may remove and get a larger Earl's unit for simplicity's sake) and notice no change in oil pressure in corners. I have a VDO mechanical gauge plumbed into the end of my canton/mecca filter housing and I get above 90 psi cold and 70 hot around town, but drops to 50ish on the track, the drop from partial to full throttle occurs in direct relation to boost pressure, you can watch the two guages move in opposite directions. The current car had been rebuilt 11k mi. ago with new rods and mains, rings, headwork, etc. although I haven't dropped the pan to check the condition. I guess I don't want to have to, hoping the builder did a good job. I have noticed higher oil pressure at high speed tracks vs. shorter tracks, which corresponds to the lower oil temps. I see at the faster tracks as well. That's why I'm thinking of a larger cooler and taking out the stock one, the stock one in series with the Earl's also might have too much flow restriction as well, which is why you see them plumbed in parallel sometimes.Anyway I though it was unusual to see the same oil pressure drop in two cars, was hoping this was something others had seen as well. P.S How do you like the Leda's?

Bill

Dave E,

Maybe you should look into an Accusump.

Dave E

I had a 3 quart one on my last car(an '86), and it didn't help, #2 rod bearing went anyway. Its for sale now.

smokey

Dave E, haven't tried the Leda's yet. I was scheduled to be at Mosport this weekend with the BMW Club, but we got SNOWED OUT. Re the oil pressure: the only other possibility I can think of is the heating of the oil through the turbo at full boost and lower speed when the oil cooler has less flow. I removed my stock cooler and have a Mocal. I've heard of using twin standard coolers, but they should be set up in parallel, according to Jon Milledge.

David Floyd

<img src="http://boards.rennlist.com/upload/Mvc-017s.jpg" alt=" - " />

Ok, my smokey, oil blowing turbo (after only 3700 miles) is back from Majestic.

This is a shot of the restrictor I made, a 1/8 npt allen head plug was drilled with a .070" hole and flush mounted.

Bill

Dave,

Nice looking plate.

I hope you have verified that the .070" hole will provide sufficient oil flow to lubricate the turbo bearing. This is what I asked John Anderson to verify with the Garrett Engineers.

If not......you could be rebuilding the turbo again!

I personally would prefer oil smoke than bearing smoke.

jimbo1111

Dave that hole looks kind of small. Are your balance shafts deleted? That looks like 1/20 of the original opening. I would be worried about redirecting oil to the path of leased resistance.

David Floyd

</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Dave that hole looks kind of small. Are your balance shafts deleted? That looks like 1/20 of the original opening. I would be worried about redirecting oil to the path of leased resistance </font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">Balance shafts are gone, yea it's a small hole.

At .070 it is a hair larger than the .062 that Tim and John use.

I will give this a try, at 4-5 bar it should still flow enough oil to keep the turbo happy and not smoke or fill my intercooler with 4.5 ounces of oil like the standard size hole did.

I put the turbo in today and have all the hard to get to bolts done, just need to put the intake on and the easy stuff tomorrow.

B951S

David
I trust all goes well with the 0.070" restrictor????

fast951

David, Not trying to tell you what to do, however 0.070" is way too restrictive!! Also, keep in mind, that any particles/sludge in the oil can block the orfice, and your turbo is history!

Ahmet

Did majestic find anything wrong w/the turbo? If so did they specify what exactly the problem was, or what they did to fix it?
Ahmet

David Floyd

B951S, so far so good.

John, good point, do you recommend any restrictor ?

David Floyd

As it turned out the turbo was not the cause but was ruined by a combination of 10-11% leakage past the rings and bad valve seals which was pumping alot of oil thru the intake and yes all of this stuff was new.

I have now installed a catch-can to keep the oil out of the intake and turbo.

Tim and I are now trying to work out the easiest way to resolve this issue and not cause either of us to much heartache.