automationgame.com

I don't if this is a bug or something, but when I was making an engine, I experience a loss 18000km MTBF on a turbochanged V8 with VVL, which too much for normal turbocharged engines. All I did was increasing the high rev valve timing. It can also be experience by making the turbine 1mm larger. I added the engine with this problem as an attachment.

It seems like some invisible threshold at 523hp for your engine, as once you exceed that via compression, ignition timing, turbine size, cam timing, or even fuel mixture, the MTBF drops sharply.