my77stang

never spanked? your taking all my fun away[]

5.0stanger

I thought that is what you wanted to get? How much extra is on there? I don't ever plan on spraying or s/c it, but I want to build it good and reliable.

MadMan@TheWheel

Blocks don't ever finish out exactly at 9.5" etc... So the point 77 made was you are better off leaving a zero deck, then should you opt for more in the future, or should you damage something there will be enough meat to do that at a later date. Normally engine builders like to deck the block then bore off of the paralell surfaces that are created when the block is surfaced. The compromise is less deck height, meaning you get into compression issues and interference issues potentially down the road depending on what it takes to "flatten" the deck surfaces....clear as mud?

5.0stanger

I got ya. I have just heard talk of people looking to get their blocks zero decked, they just want to be sure of theur exact compression ratio...right? Piston have nothing to do with the block decking though do they? I mean you don't buy different pistons for differt block heights or do you? I guess first things first, I have to get this block finished tearing down, get the crank and block to the shop and find out what I have to work with.

Is there any specfic things I should ask for while I am getting my block worked up besides the basics?

my77stang

say you set your engine on the stand and pull the heads off. you'll note that the pistons dont come all the way up to the top of the cylinder (to the deck). they will be maybe 20 or 30 thousandths of an inch below deck. by zero decking they are resurfacing the deck surface of the block until that .020 or .030 is gone. you have just removed combustion space thereby raising compression. the problem is if you need to rebuild later on and you have to deck the block you cant, cause you already took the extra meat off. with a 302 its not big deal cause they are a dime a dozen, but a roller 351w block is a little harder to find so i wouldnt wanna rape one over right off the bat like that.

btw some race motors will put the pistons out of the hole, counting on the .040 thickness of a crushed head gasket to keep the piston from smacking into the head. we have built motors where you could read the part number thats stamped into the top of the piston on the head because it was so close. thats how you build 13:1 + compression motors that use flat top pistons and stock heads

so...... to aheive a relatively equal compression ratio you can either

a) zero deck the block and use dished pistons
b) just resurface the block until its flat (probably like .005) and use flat top pistons

obviously b gives you meat for the future - and your still making the compression you want.

class dismissed [8D]

MadMan@TheWheel

No your pistons won't change due to decking. Zero decking is normally for more precise measurement of compression, correct.

No no special things you should ask for. If what you want is a reliable quicker than 302 motor. Then have it machined like a normal re-build, get high end bearing piston rings etc. and have fun with it.