What is the best way to get high compression using 64cc vortec heads on a 350ci ? Can I run a domed piston, steel shim gasket, deck the block? I'm looking for about 12 to1. Help!!!

 

I can only help you with the gasket part, but I do run a .015" (if I remeber correctly) thickness 'shim' gasket - pn fpp-1094 on my vortec 305. Its the same one that rags usually use and I havnt had a problem with it.

 

your gonna have to run more than just a smaller gasket or whatever....i would deck the block, and use flat top pistons....do you have a machine shop in your area that does the block and engine work? Usually they know right off the top of their head and they can tell you exactly what to do...

 

Mill the heads. Why do you want 12:1 compression?

 

Thank's for the info and help. The motor is for a bracket car and I'm trying to get some extra H.P. without going to NOS, etc.

 

You'll need some type of domed piston. Even if you zero-deck the block with flattops and run a .041" head gasket you'll still only be at about 10.2:1. Same same but with the pistons down .020 in the hole and a .020 steel shim head gasket only get you up to about 10.4:1. Not much difference. Remember, please, that you still need to maintain about .040" minimum piston-to-head clearance at TDC- you can't take everything down to zero.

Mill the heads down to 58cc (64cc stock) with everything as above and you'll be at 11:1.

Now throw in some mildly domed pistons (~.100" dome) and you'll be at 11.9:1. This still assumes the heads are milled down to 58cc.

Put even more radically domed pistons (.250" dome) and you'll be up around 13:1.

Still using the bigger domes (.250") but without milling the heads downs (still 64cc, like stock) you would be at about 11.9:1

If it were my motor I would build it using the 11.9:1 scenario with mild domed pistons, zero decked block, .041" gasket and the heads milled down to 58cc.

 

I don't Know about milling those vortec heads too much. Everything I've read on them says there isn't too much meat there to take off.

 

I milled my vortec heads (gave away for xmas) down to 58ccs. No problems what so ever.

 

not sure if i am correct on this but i think i read something were domed pistons and vortec heads dont work to great with each other because of the shape of the combustion chamber in the head


milling the head would be best bet