stock pistons, stock heads, with zero decking - what will the compression be?

 

Do a search for the compression calculator. Its really helpful.

 

About 11.1:1 SCR if you use stock head gaskets. I would recommend using the Felpro gaskets with .039" CH. That will give you 11.45:1 SCR. Plenty enough for the 503 I'd think.

 

So then what would my CR have been? I had a zero deck shortblock with the impala headgaskets.

 

11.8:1 with the impala gaskets, if they're .029" like I thought.

 

wow that explains the extra feel of power.

 

9formula4, what octane are you running with that compression? any problems? My block is at the machine shop now, might be worth having it done myself

 

You would be running serious risk of smacking a piston into a head . .029 quench is mighty tight, tightest you will usually see recommended is .032.

Might not happen right away but as things loosen or you miss a shift or an auto tranny lets go an overrev might be the end of a lot of parts.

 

Its not really good to run a zero deck imo....its good to leave a little there incase you need to remove any in the future.

I leave mine .005 in the hole

 

I was running 93 all the time. I wouldn't reccomend it though read below,.

Never had a problem with parts hitting at all. I see what your saying though. I wouldn't reccomend it to anyone else though. If your going to run the impy gaskets, run a stock deck height.

 

Im already running the "impy" gaskets, my LT1 was from a roadmaster. You're right though, it is good to leave some room just in case(and with the cast iron heads I should stop trying to bump the compression up, everytime I start thinking about it being done soon, I cant help myself)

 

Stock deck height is probably .020-.035 which is way too much, the few I have measured were .022-.026.

Like mdaction said, leave them a little in the hole leaves room for later repairs.

On a true zero deck the Felpro .039 gasket would be a decent choice.

If you leave them .010 down then a Victor Rienz .026 would make for a nice .036 quench and leave room for repair later. The Victor gaskets are like the Mr. Gasket only packaged better for none of the damage the Mr. Gaskets usually have in removing the wrapper.

 

using one of those silly calculators, I came up with 11.427 static and 9.012 dynamic. this is again with:

*zero decking the heads so 0.00
*a 54cc volume cylinder head, although many people say its a 58CC, and changing it to 58CC changes the numbers drastically
*4.5 piston head volume
*4.125 gasket bore - felpro
*4.02 cylinder bore - bored .20 over
*3.48 stock stroke
*5.7 rod length stock
* CC503 cam gives a 66degree ABDC

using this website http://www.kb-silvolite.com/calc.php?action=comp

I know some of my assumptions are wrong, because its not stock and I am using stock packages, but its still interesting to play around with. maybe someone could fix it for me if they are bored.

and I am in AZ so we have ****ty 91 octane and thats it!