I am getting ready to put a set of heads on a 350 that I have been working on. I'm not sure what this is called, but here's my question--ther is an area at the top of the cylinder walls as it meets the top (deck?) of the block...where the heads would sit. It is black in color, and is the part of the cylinder wall that would actually mate with the gasket.

My question--should this surface be smooth, or slightly rough? Some cylinders are bumpy to the feel, a couple are smooth, and one is actually so rough it feels like a hang-nail. Just wondering if I need to do something (polish/smooth/rough-up) to this area before I check valve to piston clearance and button things up.

Thanks!

 

The block needs overbored to clean up all the slop on the walls....you should be able to see a crosshatch pattern, but not feel bumps. There should be no bumps or waves, ridges, etc in the cylinder.

IIRC, if you can catch a fingernail on it, you've got at least .010 of wear.

As far as the deck goes, it should be smooth and true. Sounds almost as if the fire ring from a head gasket is somehow fused to the block?

 

Where did you get the 350? How many miles were on it? Is it just a stock short block? What's the purpose (are you building a cheap claimer motor or something you want to run 150k miles on street)? Depending on all that you may want to get extras done at a machine shop such as new camshaft bearings and etc.

 

yza - are you referring to a ring of carbon IN the bores, sitting right at the top of the bores, above the top ring? Just carefully scrape it off, and remove with a shop vac.

 

This thing won't last 150k miles . It had a rough life of about 5,000 miles before a kid wrecked it.

We still have the cross-pattern in the cylinder walls, but where the piston doesn't go all the way to the top--it is carbon on the top of the bores that I see. Ha Ha Ha. Live & learn. Thanks!

New camshaft, new heads, good clean-up & we'll have some fun.