Can you grind a 6.5 crank -.01?

[HANK1948]

I was wondering if you can grind a 6.5 or 6.2 crank -.01. seems like I remember someone saying its not good to because it takes the nitriding out of the journals. Is the nitriding that thin? I thought it was about .020 deep.

[DennisG01]

I could be wrong, but in conversations with Ron Schoolcraft about rebuilding my engine, I seem to remember him saying .010 was the max he liked to do. It could take a little more, but he prefered that limit. Now, I could be mistaken in what I'm remembering, but that number does ring a bell...

[Robyn]

.010 is a good limit to set.
Most 6.5 cranks I have seen can be reused simply with a pollish and then standard bearings

Robyn

[Kennedy]

I had mine index ground .010" and then had it nitrided. I don't think that they are nitrided from the factory.

[More Power]

The GM manuals say the crankshaft should not be ground. They go on to say that the deep rolled fillets are part of what gives the cast-iron crank what strength it has.

Now, the first 6.2 I had rebuilt had the crankshaft ground, before I knew better. I didn't have a problem with that engine for another 40K that I owned it. And, I've heard from quite a few others who's crankshaft was also ground during a rebuild.

Ideally, they should not be. A polish will return most used cranks to useable condition.

I get a little squeemish about grinding the crank journals, considering the crank failures we've all heard about. In the end, the choice is up to the owner. Personally, I wouldn't do it on another engine. That's just my opinion.... :)

Jim

[simon]

I got over 60.k on my 89 6.2 with the crank ground .10, this truck is used hard on the ranch.