steve c-il - 7/29/2014 20:37

I will call BS. First of all I have never had a crank failure due to the under-size alone so no fear if done by a competent machinist.

Yeah well, I have...I was talked into having a crank ground .040 once, & it lasted 90 days...rod bearing went out, the crank was soft at that depth. The best machinist i ever knew ground cranks for almost 50 years, & you had to twist his arm to get him to go past .030, if he did it was your baby. there's a reason .030 is the smallest undersize available on most cranks...

If .060 under is enough to cause a crank to fail ,it would have broke @ std. specs.

The logic escapes me on that one, I call BS on that...lots of cranks are case-hardened, you grind through that, it will either break or not hold a bearing.


.Second is accidentally grinding that much off a journal let alone four of them. I would suspect that there was a set-up error or some one made a mistake during the turning process. Needed to go .060 under to cover their arse. One other possibility is they did you a favor.

I agree on that, somebody screwed the pooch...

Many "stock" race engines have had their cranks offset ground deliberately to gain almost .055 inches of stroke and also raise the compression ratio . You need to have an honest set-down with the shop owner. steve