compression ratio?

[TCIC 300ci superbeast]

what is the equation for finding c.r.
im guessing BDC volume divided by the TDC volume?
or am i wrong?

the resion im asking is im building an engine that will be bored and stroked and i would like to know how tall of a piston i need get to get a 9:1 cr

 

[rbohm]

8) cylinder volume+head gasket volume+combusiton chamber volume+piston dish/dome volume=total volume at bdc.

total volume a bdc/total volume at tdc=compression ratio

 

[XPC66]

1 + (Swept Volume/Clearance Volume)

 

[Thad]

The piston top recessed volume is important. The optimum piston choice would be one that when installed the compression height would be at zero deck. The piston recess volume being enough for the cr needed. This piston choice would have the best squench and the greatest chamber turbulence, best air/ fuel mix.

 

[TCIC 300ci superbeast]

do stock pistons have 10.5 cc?

i need a piston with a 17cc dish. what do you guys suggest?

i have been looking. and the most cc i can find is 12cc but that would put me 9.4:1 plus big boost.....

 

[66 Fastback]

Here is a link to calculate the CR
http://www.csgnetwork.com/compcalc.html
Doug

 

[BaldvinE]

do stock pistons have 10.5 cc?

i need a piston with a 17cc dish. what do you guys suggest?

i have been looking. and the most cc i can find is 12cc but that would put me 9.4:1 plus big boost.....

Not sure on this, as I'm a complete novice at this, but through the FAQ's I found forged TRW pistons made for the 351W with a ".160 dish" wouldn't that mean 16cc?
Then maybe the head gasket will solve the remaining 1cc ...

And 351W pistons are supposed to fit the 300, right?

here's the site, though you'll have to do some digging, as the url doesn't change once you're on the page
http://www.flatlanderracing.com/index.html

Go to pistons on the left, then choose TRW>Forged/Hypereutectic>Ford>small block then scroll down till you find the 351W

 

[TCIC 300ci superbeast]

cool thanks.