hi all, i had just finished rebuilding my 2wd cossy engine on tuesday, i span the key it ran for about 7 mins then stopped with a big bang!
i checked it out and no 1 inlet valve had snapped off and mullered the new piston i had just put in. long story short is that i am trying to find out why, i had the machining work done by a guy who used to work for fords he bored the block to 0.5mm oversize with standard comp pistons put 9 new valves in the head as he said they were bent and skimmed it, i put the engine back together and i no for sure the cams were in the right sides and that it was timed up properly. i have had the cams measured and they are standard, i have had the head measured and it is 0.18mm shorter than fords minimum spec but am unsure 0.18mm would be enough to snap a valve? i have done piston pertursion measurements and it is 0.45mm but can find no specs for it can anyone please help. cheers dan