What do you guys run as far as the tolerance for your line bore on your engines? My new engine builder says that the reason my main bearings got chewed up in only 8k miles was due to an improper tolerance in the line bore. He says on race engines he uses around half a thousandth and on street engines never more than one and a half thousandths. After disassembling my engine and checking I had around two and a half and the bore was never touched.

If this is way out of spec I am planning on going after my old machine shop for negligence on their work because my rebuild is costing a fortune. This isn't the first bad thing I've seen from this shop either....the machinist ordered me regular pistons last time instead of stroker pistons and assured me that cutting the skirts on them would be fine. Well guess what....upon disassembly there was a broken piston skirt laying in there!

Please let me know what spec you guys usually look for.

 

.0015 is pretty much the max

 

Thanks Ede.....I guess it's safe to assume then that I shouldn't have much problem proving that it was the machine shop's fault? I know I should have checked it myself, but I wasn't exactly experienced and I was young and naive.

 

my guess is even if they are wrong they'll not admit it knowing they are and even if they do admit it i doubt it helps you recover any expenses

 

True, however my new engine builder has agreed to document all of the measurements prior to machining the block. Also I have a lawyer service through work that is dirt cheap so if worse comes to worse I can use that. The old shop already agreed to try defecting out some of the parts, but I want more than that now.