Engine rebuild: Crankshaft

[birdman24]

I tore my motor apart to find that the rod bearing for cylinder #1 decided they didn't want to do they're job anymore and spun a little. The bearings left very small scratches on the surface of the crankshaft where the rod bearing sit for cylinder #1. The owner of the machine shop said that it would have to be turned. I heard that our cranks should never be turned, is this true?

 

[AnotherNewb]

Yes it is true. There is a coating or something on our cranks that cuttin the crank removes. Your best bet is to find a good used crank and having it polished.

 

[Barnes]

Our cranks have a surface treatment called http://en.wikipedia.org/wiki/Nitriding

 

[AnotherNewb]

Yeah what barnes said.

 

[boostedinaz]

Barnes is correct. The Nitrading also goes so "deep" into the crank. When the machine shop cuts it down they cut off the layer that has been nitrated. Many people have had good luck with cut cranks and to be honest I doubt it would matter even in a decently modded motor but why chance it?