Engine failure
03-19-2019, 07:00 PM
#1
Engine failure
My 996 c2 2002 engine became junk last autumn during a track day. One of the connecting rods stuck to the crankshaft and totally ruined the engine. I have found a new engine but why do you believe my old engine had this failure?
My old engine seemed to work just fine before the crash and was well maintained.
Robert
My old engine seemed to work just fine before the crash and was well maintained.
Robert
03-19-2019, 07:03 PM
#2
Rennlist Member
Sorry to hear that.
Rod failure has been an issue on these. A google search will give you some more data.
Rod failure has been an issue on these. A google search will give you some more data.
03-19-2019, 07:27 PM
#3
Rennlist Member
Track use is hard on engines. At this hp / liter level lots of things are a compromise. If I had to guess I’d suspect oiling issues during track conditions to be a contributing factor.
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03-20-2019, 07:53 AM
#11
My mechanic didn’t think it had anything to do with oil starvation (he is racing himself in a boxster). He thought it had something to do with overheating issues or a bearing that got damaged with debris of some kind. He said that if you race and then suddenly switch of the engine the heat can increase and make the bearings stuck. I usually cool down before I stop after a track session, but maybe not enough.
I already have a deep oil pan with x51 baffles. Unfortunately I can not really afford a turbo or a gt3, but sure they are better prepared for the track.
Any other thoughts ?
Robert
I already have a deep oil pan with x51 baffles. Unfortunately I can not really afford a turbo or a gt3, but sure they are better prepared for the track.
Any other thoughts ?
Robert
03-20-2019, 10:37 AM
#12
Captain Obvious
Super User
Super User
The engine has to be red hot for those bearings to stick. You would have plastic pieces on top of the engine melted to the block if that was the case. Lack of lubrication is probably what did you in. Boxters have a better engine placement so high G corners have less effect of the engine lubrication.
03-20-2019, 12:11 PM
#13
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I had exactly the same failure with my 2001 3.4 which was equipped with a baffled sump and an extra scavenge pump as protection against starvation. Following the engine failure at Mosport, It was sent to Jake Raby for a rebuild and after assessing the failure he attributed it not to oil starvation but to breakdown of the oil, under the high stress of track use, leading to loss of viscosity and oil pressure, immediate wear of the con rod bearing and eventual failure of the bearing and the con rod. He actually sent me a graphic detailing the stages, under track use, that lead to failure due to breakdown of the oil leading to loss of viscosity and pressure . He calls it "the snowball effect". I had been sharing the car with my son that day so it was running in two run groups and the oil presumably had the chance to get real hot. So for mine, the identified cause was not starvation but oil breakdown (Motul at the time). The propensity for such failures is why Jake specs Joe Gibbs XP9 oil for track use in his engines.
03-20-2019, 01:40 PM
#14
Rennlist Member
I had exactly the same failure with my 2001 3.4 which was equipped with a baffled sump and an extra scavenge pump as protection against starvation. Following the engine failure at Mosport, It was sent to Jake Raby for a rebuild and after assessing the failure he attributed it not to oil starvation but to breakdown of the oil, under the high stress of track use, leading to loss of viscosity and oil pressure, immediate wear of the con rod bearing and eventual failure of the bearing and the con rod. He actually sent me a graphic detailing the stages, under track use, that lead to failure due to breakdown of the oil leading to loss of viscosity and pressure . He calls it "the snowball effect". I had been sharing the car with my son that day so it was running in two run groups and the oil presumably had the chance to get real hot. So for mine, the identified cause was not starvation but oil breakdown (Motul at the time). The propensity for such failures is why Jake specs Joe Gibbs XP9 oil for track use in his engines.
03-20-2019, 02:13 PM
#15
Race Director
