Help Smoothing Engine Block?

Has anyone smoothed an aluminum engine block? I have used 80 grit to start with and have gone back over the block with 120 grit.

I am considering using glass beads and bead blasting the block as a final finish. Any thoughts of if this would be a good or bad idea?

The block will be painted after machine work is finished. Any recommendations on primer and paint so that I get a good finish that can stand up to the heat?

The block is an LS1 aluminum 5.7L block.

Thanks...Kevin

 

Not to sound like a jerk but search is your friend.
http://www.jalopyjournal.com/forum/showthread.php?t=377850
http://www.jalopyjournal.com/forum/showthread.php?t=226157

 

Thanks. Actually did a search and got some results but the threads you included were not in the results. Already looks better than the first set of threads I went through.

K

 

Unless the engine will be exposed, pretty much a waste of time. I had a 215 olds polished in my 37 Ford and you couldn't tell it was polished, even with the hood open. Stu

 

I knew a guy who glass beaded his engine before rebuilding it, to clean it.
It ran all of about 3 minutes before it siezed up.
I wouldn't take the chance you'd get beads anywhere you don't want them!

 

I built a 4 cylinder engine that the guy polished, again when the engine was assembled and in the vehicle you would have never noticed if it was polished or grey

 

I have seen some smother engines in open cars and they were OK to look at. I am assuming that what you are smoothing is the big lumps etc???

bead blasting is not a good idea. I have done it to motor cycle cases and you spend hours upon hours making sure that there is not junk in any of the passages.

Just smooth it with finer and finer grit until you are happy with the look. Then wash the hell out of it. If it is greasy you should have actually adressed that issue before getting the grinder involved.

Do a search on painting aluminum what you want is a primer with zinc chromate in it to start with. Then if you want durable paint that will retain its gloss you want to use a 2 part epoxy. Make damned sure that you mask everything where you do not want paint because it is a bitch to et off out out of holes and crevices. Lifter bores and cylinders are a major problem as well as threaded holes. You will need to chase the threads in every hole after painting anyway but that stuff will destroy your taps so keep as much of it out if the holes as possible.

Another option is powder coating your block when you are done. but it is very pricey and unless you get it to a good coater you are going to ned up with your block all screwed up.