Very close tolerances. Not supposed to machine the head, don't know how you could screw the deck up. You might find a machine shop that would think about it, a new engine would probably be cheaper.

 

Because the block is separate from the cylinder sleeves, it is not possible to machine the block deck.

 

Hey all, I'm back again. I bought an extra engine to swap into the car so that I don't have the car sitting in the garage too long. I picked up a 2007 cobalt block with ~50k miles on it and started rebuilding it yesterday. The pistons were very dirty but cleaned up well. The bearings look almost brand new. I'm considering replacing them anyway since they're only $25 for a set.
The only concern I have is with the cylinder walls. There's a little bit of surface rust on the walls. I'm used to working on linerless aluminum blocks, so I'm wondering if the bore is fine or if I should ball-hone it? Maybe I should just hit it with a light gray scotch brite?

 

A quick ball hone should clean the cylinder liners nicely.

 

Thanks, the ball hone worked great. Might not be perfect but definitely cleaned them up

 

You may want a more angular crosshatch pattern so they break in good.

 

Do you have any pictures of what they should look like for a good angle? I tried going for a 45 degree angle

 

45 is the correct angle. You are around 30. To stretch them out you need to increase the rate at which you plunge and pull the hone. It's best to practice until you find what works for you.

 

Thanks for the tip, I think I got a little closer to 45 now

 

Looks good.