heinrich

Agreed. Moil One is race proven, and used every day in thousands of race and other high-stress applications. It is easy to blame Mobil One, or the tooth fairy, or the gear ratio for 2/6 failure, but ultimately the answer is very elementary ..... BAD ENGINEERING. And the solution is equally simple .... ACCUSUMP. While an accusump (sp?) does not SOLVE the problem, it WORKS AROUND it with 100% success rate, at a cost of a whopping 300 dollars.

drnick

heinrich, i think there have been 2/6 failures with an accusump installed.

heinrich

Nick the only one I know of was Don Hanson, and his was as a result of off-track and a severed oil feed line?

johnb

Well th engine is ready for a lift in the morning, all disconnected and just sat in the engine bay.

Things found so far:
1. cam timing still spot on
2. oil is filthy/black only been in for about 300 miles
3. small amount or shiny material on drain plug:

The oil was a Comma semi synthetic 10/40, oil and filter changed 4 days ago. Car has always been on this oil (4 years) and completed two previous track days.

Yes the rev limiter had been hit, but only in pit straight. Although high revs held aroung both left and right turns (5K) some times.

john

Abby Normal

+1

The racer I bought from Constantine is suspect of having the same failure and was running an accusump also.

SwayBar

And Mark Anderson had a failure with a dry-sump installed; the 2/6 bearing carnage did not stop until after he drilled his crank. Joseph has been running an Accusump with a drilled crank for many years without a failure. So it appears that drilling the crank is a key piece of the puzzle.

That is a sure sign your bearings are gone. While you're waiting to pull the engine, cut open the oil filter to see how bad it is.

Did you cut open the filter after each of the previous two days? If you didn't, you may have seen this coming by the debris in the filter.

Bill Ball

Dennis Kao had two failures despite Accusump. His new crank will get drilled and we are examining other changes to the oil feeds in the block.

johnb

I change the oil every 3000 miles, I have done 22,000 miles in the car since I have owned it.

So I have probably changed the oil and filter about 7 times, there has NEVER been any hint of debris on the magnetic drain plug.

I had recently fitted a new sump gasket, and the sump was sparkly clean with absolutely no evidence of any debris.

The crank, and all its journals showed, showed no heat damage at that time. End play was well within spec.

So i am fairly certain that the damage was caused yesterday and was not on going.

I will cut the filter tomorrow and let you know what I find.

John

Art_Z

has anyone ever documented this issue happening from street driving?

johnb

Forgot to say, the engine turns over quite easily with a socket and breaker bar on the pulley bolt. I had to rotate the engine to remove the clutch.

Does anyone know why the engine ran so rough, I appreciate it would have bearing damage, but why rough running? especially as it shows no sign of any tight spot when turned over by hand.

Also the rev counter stopped working as soon as I lost oil pressure, all other instruments fine, well - oil presure reading low !!!

John

Jim bailey - 928 International

You can not drive hard enough fast enough on the street without being dead or going to jail....

mark kibort

amen!

mk

mark kibort

dont take it apart. we have a brand new 4.7 ready to go, and its a euro S as well. barely been broken in, 250rwhp with LJet running it. sitting on a pallet ready to ship.

the cheap route would use a set of rods and crank, that also has the larger oiling holes. both from the same, well running street engine.

Let me know if you are interested.

rods and crank $300
almost brand new euro 4.7 , $1500

mk

mark kibort

key term is "thousands" (in other types) of race cars.

the 928 either is very sensitive to viscosity break down or foaming. either way, its cheap insurance to use the oil that some uses and has more racing miles on it without failure than any 928 in the world, by a factor of 2 minimum!

redline or amzoil seems to work the best.

and as was mentioned, there has been a few failures with accusump as well. I think the drilling is the most effective fix, but dont discount the oil quality and characteristics at 280F temps, where most engines never see this kind of temps, nor do most other race cars that i see at the track (BMWs for example are 220 to 250F max)

mk

Stan.Shaw@Excell.Net

I have had two both with Amsoil and Accusump.
I believe David Lloyd has had at least 1 and perhaps as many as 3 with Amsoil.