Crank regrind questions

[tonytee3]

Ok I've got an r53 cooper s and I think it's got a knock from the bottom end.
Has anyone here delt with this and had the crank reground and new shells fitted? Did you have any other problems?
Thanks.

[fatboy b]

Surely if the crank is shot, then there’s a good chance the bores and cam(s) are too. Wouldn’t it make more sense to rebuild the whole thing?

[E-bmw]

Not beyond the realms of possibility if the oil has run low, but are you sure, as the bottom ends on these engines are pretty bulletproof?

[tonytee3]

Fatboy. Yes I'm going to rebuild the hole engine but just wanted to know if there was any problems before I get stuck in. Engine now out.

E-bmw
I think it's the bottom end but to be honest there is so much noise from the chain I'm not sure. If they are bullet proof then maybe it's all noise from the chain. The oil was really good and it has got plenty of service history and no shiney bit in the oil so maybe change the chain and clutch and put the bad boy back in.
This is my first cooper s and wanted to ask the people who know before delving in head first.
Thank you for your reply.

[E-bmw]

Not a problem, happy to help when I can, these engines are routinely turbo converted & being semi-closed deck (whatever that means) & forged as standard they regularly get taken above 400 bhp on a standard bottom end.