Blew another motor

[Pranav]

Running out at TWS (CCW) today, car felt tight and great, then I went off on T2, bumped a curb getting back on like an idiot.

Watched gauges like a hawk with plans to pit out for an inspection, motor locked up approaching T13-T14.

Thought I might've ruptured the pan and lost oil to cause this, but first look shows back of pan to be fully intact. Front of pan of course is chewed up from the rotating assembly trying to leave the motor through the pan. I don't recall an oil pressure warning or obvious signs of smoke out the back BEFORE it let go and siezed.

I'll know more once I pull the motor and have a clear view of the pan, to see if it was me and my bump that caused this. Unsure how else a motor that, after 5 weekends and three dyno sessions, returns clean oil filters, does not run lean (fuel trims and measured A/F) , nor does not misfire can go boom with no warning.

I've got the LT1 pull/undress/dress/install down like the back of my hand now. Part of me wants to get this sorted out by Cresson, part of me wants to throw in the towel and take a break for a while.

Anyone got a short block and heads?

[Supercharged111]

Do you lose oil pressure in the corners? Do you trust your engine builder?

[Pranav]

The engine builder comes highly regarded in Houston, I will not post that business's name on a public forum.

I'm not sure about the oil pressure, I have the warning set low and it has never once gone off (backed up with data logs) the entire time this motor has run. Running a canton pan filled correctly and verified oil pump pickup depth was set correctly by builder before I bolted down pan/gasket myself.

One step at a time, if I pull the motor tomorrow and see an obvious crack from an off-track I have answered that question.

If not I'll give the builder a chance to look at it, but I will shop for another builder if it looks like a build issue (struggling to see how).

[Casey_SS]

Really sorry to hear this Pranav, that sucks! You say the back of the oil pan is intact as far as ruptures go but is it dinged up at all? It's possible the curb could've knocked it just enough to squeeze the gap between the pickup and the bottom of the pan. It wouldn't take much - 1/4" or so IIRC. Were you maybe running a long oil filter that took a hit? Pretty suspicious to have the motor completely seize less than a lap after the off...

[Supercharged111]

What's crazy is how my motor survived 2 races last year with seconds long intervals of virtually no oil pressure. My water pump drive oil seal walked out and halfway through a race I'd lose nearly all pressure in a corner. It took a few seconds of a straightaway to restore pressure, and with corners packed together it didn't always recover. Why didn't I stop? First time in my life I was leading the pack. My point is your motor may have been dealing with an oil delivery problem for more than just one lap.

[Pranav]

I get what you're saying, but wouldn't I have been picking up material in the oil filter if I had an issue? I've pulled 7 clean oil filters since June...

Anyways further inspection of the oil pan shows nothing that would indicate a puncture or dent, in fact I was able to manually drain a ton of fluid this morning so the bottom of the pan was not punctured. Just got the drive line out and on the floor, taking stuff off tonight and should get a closer look once is elevated.

[Pranav]

I also neglected to mention that I've been having a hard time operating the steering wheel since MSRH. I don't like to make excuses but my recollection of my last two offs (MSRH and yesterday) involved me fighting the wheel (but yes other factors always contribute).

Swapping pumps hasn't done anything (I keep a spare).

Probably will swap the rack too while I'm in there, just AC Delco this time.

[Pranav]

Oh yeah and to answer your Casey, I don't run a long oil filter, it sits about 1-1.5" above the bottom of the pan. The nice long 2 Qt filter would sit below the pan and would've been a hazard...

[Supercharged111]

Probably will swap the rack too while I'm in there, just AC Delco this time.

Have you considered a Turn One rack?

[Pranav]

It is a Turn One rack. Went in the car in Nov 2013.