Crankshaft groove

[Zach Baumann]

On disassembly of my fresh engine ~5k miles I noticed the crank looked pretty good minus one groove I can catch my nail on, on the number 7 rod. How you would guys go about fixing it?

 

[Dino Dino Bambino]

I'd take it to a machine shop where a technician can determine if it'll be OK to have the journals reground undersize.
That said, I'd be concerned about how that groove appeared in the first place (likely to have been caused by a piece of debris).

 

[JC SSP]

Dino is 100% correct. Machine shop can assess and determine what is the best solution. Sometimes a good crank journal polishing will take care of the issue too.

 

[MasterofDisaster]

I used to work at a machine shop in Denver that could weld some new metal onto the crank and then grind and polish it to the correct diameter. I believe Zimmer Automotive went out of business years ago, but the technology clearly exists.

 

[Juice]

I used to work at a machine shop in Denver that could weld some new metal onto the crank and then grind and polish it to the correct diameter. I believe Zimmer Automotive went out of business years ago, but the technology clearly exists.

Submerged arc welding. Crank spun much like on a crank grinder around the journal being 'rebuilt'. Weld is under a constant flow of ground iron/steel. Once the journal is welded, crank must get straightened. Than the weld rough ground. Now its ready to be reground/resized. You don't want a welded crank in any performance engine. I sure as hell don't.

Depending on just how bad the scoring is, it could possibly be polished, and bearing replaced. If it needs to be ground, might as well look into a reman crank kit.