So I think I'm going to punch it over a few thousandths and I was wondering the pros and cons about .020 vs .040. I have a thread for a price on rings, pistons, and wristpins but u you guys have any advice to help me I would appreciate it.

Brandon

 

Why are you even boring it out? I wouldnt do anymore then you have to.

 

I had it honed out as far as a could go butt there is still glaze marks on it.


Brandon

 

Just go as far as it takes. Performance wise you won't gain much. If the walls are just glazed a hone should have taken it right out.

 

The hone took most of it out but there is still two marks at the top of the cylinder wall when it fires. The guy at the machine shop said it should be fine and you can't feel anything. It's just food for thought and me knowing that it's there.


Brandon

 

That part of the cylinder doesn't effect anything you'll be fine running it like that. As long as you can't feel it and the cylinder isn't out of round or tapered run it.

 

Alrite thanks. That makes me feel better. I felt around for 30 min tring to find a hump or miss round and it's all smooth.


Brandon

 

You're golden. My attitude about boring over is only do as little as possible. You here small block chevy guys and stuff brag how "she's bored 40 over!!" and it's like, "yah, so now you got a 351.75 instead of a 350. Oh wow....."

Overbores are for future repairs. If you jump to the max now and say, break a ring or something, then youre out of luck and going to have to pay the money to either replace the block or have it sleeved.

 

Good enough for me. Makes good sence too. What's ur theory on the break I'm process?


Brandon

 

Main thing on a 12v cummins is they are commonly out of round more than anything .010 over took out all of my bad spots and trued it up, but ther arent kits out ther for .010 they start at .020 from cummins so i had it punched out .020 over, if its outa the truck and stripped down take it to a shop and have them check it, build it to last, same for the crank to hve um polish it and if ne scratches or marks still exist hve it turned, i hve a custom offset ground crank job on mine costs a lot but i was needing to thro some money around and put it in my engine