[OZ38]

Gidday,

As the title says Crank Polishing. What exactly is this process and whats involved ? Is it machining the counter weights and further rubbing to a mirror finish, or is it grinding lumps and bumps off ?

 

[1Hot97]

While I'm not sure exactly, I think it's a process of polishing the journals to a mirror finish, reducing friction and relieving any stress cracking that may occur.

 

[OZ38]

Ok I thought they called that process linishing.

Maybe it is a form of polishing too. I had heard of people talking about polishing as if they were working on the counterweight area and surrounds.

 

[Gurr]

I had my crank polished. I took it to a machine shop where for about 15 minutes and $40 I stood and watched them polish my crank. First they check to make sure all journels are perfectly round and then make sure there are no imperfections. Then they buff the journals to a mirror finish. This does not change the size of the Journals so you don't have to go with larger bearings, unless the crank needs to be ground then you will need larger thickness bearings.

 

[OZ38]

Thanks Gurr, sounds like polishing is just the journal area only then. I thought their might have been some benifits in cleaning up the imperfections on the rest of the cranks casting. Maybe not.

 

[bumpin96monte!]

I've heard that done on V8 cranks, many of the performance building books for them says to smooth out the casting line on the crank b/c it is where stress cracks can start. I think that may be called "grinding the crank" and the work on micropolishing the journals is called "polishing the crank", don't know if anyone has had the casting imperfections smoothed on these engines yet or not though.