Refurbing a crank after a spun rod

[2Chainz2]

Just had my 2011 n55 with 50k miles spin a rod bearing, I am thinking rebuilding the motor over just replacing it is the way to go. That way I can do rod and main bearings as well as forged internals. My question is does this make sense to do? Can these cranks be repaired reliably after a spun bearing?

[iminhell1]

Only a good machine shop can answer that. It'll depend on how much they need to cut to clean the crank up and the availability of bearings. And there's no way for them to know without having the crank in hand. Your visual description or photos of damage are not exact measurements.
But odds are the crank can be saved and there are bearings that can be used.

The local Colorado N5x guys should know who to go to for machine work locally.

[N55135i]

What resulted in the failure?

[Petro135]

Ive an n54 but just went through this. My crank had cyl 4 spun bearing. Brought it to my machine shop and they said it was mostly bearing gook on it and they are cutting it down to accept the oversize king bearings. But they are 40 engines behind at the shop so I found a used crank for $500 in beautiful condition and just bought it to get my build started. Good thing I did they have had it there since June and its still not done

[2Chainz2]

Finally pulled it apart it looks like 4,5,6 all had smoked rod bearings the crank journals honestly looks pretty good. N55 cranks seems to be pretty expensive and if I really want to replace it I should probably try to find a crank for a n55 m2 since its forged. Adding pics let me know what you think.

[Petro135]

Dont know if its the pics or not but that crank doesnt look too bad. Does scraping your fingernail across it get stuck in any grooves?
Heres a pic of my spun bearing. Looks like yours is in better shape

[2Chainz2]

You feel no scaring or gouges at all just feel smooth, it is a little more dull finish then the other journals but feels smooth

[Petro135]

Originally Posted by 2Chainz2

You feel no scaring or gouges at all just feel smooth, it is a little more dull finish then the other journals but feels smooth

You might be ok. Take it to a local machine shop and see what they say. If you have a crank to start with you save alot of money. Mine was machined for $150