by Jim » Sun Aug 28, 2011 6:39 pm
Well, they were forgies. Wasnt killed by detonation either.
Came down to poor workmanship from 2 places, MRT and the Head Shed in Seven Hills. MRT assembled the engine dirty, didnt check clearances and honed the bores poorly. Every piston skirt was scuffed and nearly every bearing was down to the copper due to scoring from dirt between the shells evident from assembly. It wasnt going to last long anyway! Lucky i wasnt the one who forked out $10k to have it built.
What killed the engine was the poor work done by the head reco job. From what we could see, the valve seats hadn't been cut off-square to the guides and over time fatigue set in and the stems cracked. One exhaust valve eventually gave up, snapped and took everything else with it while at about 80kmph.
What the real moral of the story is, no matter if the engine is stock or built, and however much you look after it, shit can and does go wrong. I babied this motor and had all supporting mods and did everything i could to keep it 100% but unfortunately, you cant see what goes inside and you sometimes you cant trust professionals to do a good job all the time.