Oh geez, that's a tough one. I don't think there is any one thing that caused this, but there are probably many things that contributed.Benckj wrote:
For the benefit of others can you simply list the factors which caused this failure?
- Its a race car
- Pistons are 0.5mm oversize.
- I've gone thru a few heating problems so it has been hot in the past.
- I've not long ago added ARP 625+ head bolts, with their extra torque forces into the block, it cant have helped (but they sure clamp hard)
- Have recently re-tuned on E30. Alcohol increases combustion pressure.
- Re-tune jumped power by over 25%
- Engine was cold and I gave it a bit of a "launch" to get in line in the track pit area, engine made a slightly funny noise (not quite a pop noise)
wam bam, that's how you get cracks where you don't want them, well in my case anyway.