i just blew a piston ring on my 305 so i am droping a 350 out of a 1990 chevy truck or caprice, not sure which it is out of, in my car i was wondering what my compression was going to be it is stock bore, stroke, it has 5.5cc valve reliefs in the pistons, and i am using a normal set of felpro gaskets for my 350. My heads have 58cc head chambers on them. I am expecting my compression to be high but i was wondering what it will actually be.

thanks in advance

levi brohez

 

You need to know how far below the deck the pistons come up
at TDC (compression clearance) On a stock motor it should be .025 to .045" Measure it.
Then you can calculate it here.

Compression Calc

 

10.29. Not that bad

Auggie

 

my brother has a 79 block, with the same style of pistons, same size heads would his be the same.

ps. could you tell me all the measurements you use to enter into the diffrent boxes.

thanks in advance

levi brohez

 

1= inches 2 =metric
bore stroke gasket diameter 4.166 thickness .039
piston valve relief volume 5cc (typical 4 eybrow relief flat top piston)
piston deck clearance .025" to .045" on factory motors (you have to measure this dimention to get accuracy.) less if the block has been decked.
Cylinder head volume cc's

 

Sure.

Bore = 4.00"
Stroke = 3.48"
Head Gasket bore size = 4.166"
Head Gasket Thickness = .039"
Cyl Head cc's = 58
Valve relief cc's = -5.5
Deck = .025"

C/R = 10.49 oops not 10.29

Auggie