BMW Crankshaft Restorations Recommendations - Shop

[Motorsport1207]

Recommendations
Crankshaft restoration in Wisconsin, Illinois, Iowa or Michigan.


Looking for a shop that specialize in BMW crankshaft work

Journals welding and. Machining,
Journals under sizing
Crankshaft balancing

Thanks
Ted


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[digger]

In princple if you need that type of work i would reconsider a new crank or different unless doint something "different".

Have a chat with Jim at Metric mechanic. They take s54 cranks and offset grind from 91 to 93 stroke and convert them to the smaller 6cylinder big ends size to use in the povo M50/52/S50/S52. not sure who they use or if done in house, i dont think they do any welding though.

[varg]

Agreed with the above. Unless it's a rare crank it probably is cheaper to find something in usable condition. The owner of my local crank shop told me most of his crank welding jobs are typically rare or very expensive crankshafts, with a row of porsche blocks lined up on a shelf and several old V12s around the shop I'm inclined to believe him. I watched him peen my 89.6mm crank straight and it was cringe inducing to watch but that's apparently how it is done.

Have a chat with Jim at Metric mechanic. They take s54 cranks and offset grind from 91 to 93 stroke and convert them to the smaller 6cylinder big ends size to use in the povo M50/52/S50/S52. not sure who they use or if done in house, i dont think they do any welding though.

Ah, so that's how they get high RPM out of the NA strokers safely. I was wondering about that, having this 3L M50 which has an M54/S52 crank in it (bad for high rpm by most accounts).

[digger]

Ah, so that's how they get high RPM out of the NA strokers safely. I was wondering about that, having this 3L M50 which has an M54/S52 crank in it (bad for high rpm by most accounts).

its done to get more displacment for their 3300 rally foremost, they still do 3200 rally with the M54/S52 crank which seems to rev atleast as high

[Motorsport1207]

Thanks for the feedback. Mostly the trouble crank that I am mostly concerned about is the V8 S63 crank.

A new one is pretty pricy. Looking to get undersize and make sure no surface hardness is not compromise in the process.

I am pretty sure these cranks are only surface hardened and not through hardened, any under sizing could remove this hardness layer.


Thanks Ted


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[digger]

Lang racing offer this service but not sure who they use

id look for a good used one, still be spendy but almost zero risk compared to extensive work that is probably barely going to be cheaper than a good used one