Proper Head / Block Preperation for HG install ???

[95CobraMike]

What is the proper preperation for installing head gaskets? meaning do i sand the surfaces, or just make sure all the crap is off from the old stuff?
putting on new Cometic head gaskets, and i have heard they are picky about block/head prep.

thanks

 

[wytstang]

Just make sure they are clear of crap. If you want use a razor blade and go over them.

 

[mackey]

Putty knife, then use laquer thinner and go over it and make sure no crap is left on it.

 

[S/CBlack95GT]

I use a scraper that you can get from Autozone to remove the big chunks. Then I use a tough dish scrubbing pad of some sort with acetone.

 

[95CobraMike]

ok...thats what i did last time...
i did razor blade, then this sand paper type pad thing from 3M (330 grit) , then brake cleaner...there wasnt anything on them...

 

[S/CBlack95GT]

Id be careful using sandpaper or anything like that. The grit can get down in the engine.

 

[95CobraMike]

it was blown out with compressed air after the stuff was sanded/scrapped off... then i did an oil change and coolant flush right after..

 

[mo_dingo]

it was blown out with compressed air after the stuff was sanded/scrapped off... then i did an oil change and coolant flush right after..

The best way is to get a 110V corded drill (or a really good cordless drill, b/c you will need to use it for very long durations), and hook up a wire brush wheel to it (get them at home depot). You may want some 1/4" hex extensions.....Get multiple grades of coarseness so you have a choice.

This way the block is nice and shiny & you will get all of the carbon off the pistons. That is what I did. That will decrease your chances of pinging in the future, and it will ensure a proper HG seal.

A scraper can also scrape the metal from the block, and the pistons. Trust me, I did. The carbon can be really stubborn and heavy scraping is usually necessary. The wire brush will eliminate taking excess metal away.
Scott

 

[95CobraMike]

thanks, i'll try that, i have a wire brush attachment here