Oh crap. What should I do?

[Mike_Yi]

Originally Posted by Steve Tinker

I feel for your predicament having a major breakage like that. I think Porsches fitted with the M96 engine that are tracked really need the deep sump kit that helps prevent oil starvation under high cornering loads.....
As a matter of interest, how was the main bearing damage diagnosed?
You say that the car has been "running fine" after the initial vibration & rough running - I would have thought that you would have heard a bad main bearing, even at low revs.

I didn't ask how he determined it was the bearing, but he did say it was scored. He said he didn't look at the crank. Not sure how he got a look at the bearing, especially since they didn't start looking at the car until late in the afternoon. I'm going to ask him tomorrow.

When it did finally stop running, I did hear a bearing noise.

Everybody told me that I only needed a deep sump if I had slicks. They said you wouldn't generate the Gs with street tires that could cause scavenging. I guess they were wrong.

[Jake Raby]

Actually the engines that fail on the track only appear to fail from starvation...

Most fail because their oil temperatures soar and the oil doesn't have the capability to protect the components or maintain pressure at these temperatures that are generally 250-265 degrees.

Here are some examples from one of our test cars running a bone stock 3.2, just purchased in May of this year from Porsche. The oil was Mobil 1 10/40 for these tests, we used these for baselines for ongoing lubricant development.

When an engine dies due to a lack of oil pressure from overheated oil, the symptoms will fool many into believing the issue is starvation. This data suggests oil that is being cooked well beyond the point where pressures drop off significantly.

That said, I may have a buyer for the car with the blown engine.. I have a wait list of those who are looking for a car to equip with an upgraded engine who don't care if the engine is currently scattered.. It won't bring much, but at least you can move it.

[Mike_Yi]

Thanks for the info Jake. I may be giving you a call tomorrow.

BTW, I don't know that the oil was an issue. I didn't have any warning lights when the problem first occurred.

[Jake Raby]

BTW, I don't know that the oil was an issue. I didn't have any warning lights when the problem first occurred.

You won't. Thats because their is no warning light for overheated oil and the oil pressure has to be at a point where the pressure is so low that the engine is already dead before it illuminates.

They call them "idiot lights" for a reason :-)

[Mike_Yi]

Originally Posted by Jake Raby

You won't. Thats because their is no warning light for overheated oil and the oil pressure has to be at a point where the pressure is so low that the engine is already dead before it illuminates.

They call them "idiot lights" for a reason :-)

Ah. "Illuminating" (pun intended).

So, if the oil overheated, and there was insufficient oil pressure, that means not only is the bearing shot, but the whole engine probably suffered severe wear. Right?

[Mike_Yi]

I also wonder what could be done to prevent that. Would a center radiator cool the engine enough? Would the 160 degree thermostat be enough? Or is there an aftermarket oil cooler? Seems like that would be the best solution, though I image that would increase oil pump requirements, and capacity requirements pretty significantly.

[Steve Tinker]

What happend to you (and Jakes printout confirms) is why Porsche do not use the M96/97 engine in their serious performance or race cars. Especially without some major internal upgrades
The engines in the 911 Turbo / GT2 / GT3 are completely different to the M96/97 series Boxster / Carrera cars, being genuine dry sumped 70 series engines, originally from the GT1 racecar.