Quote:

Using the Kb Calculator:
Entered these specs:
Cylinder Head 79cc
Piston Head 20cc
Gasket thickness 0.040"
Gasket bore 4.5"
Bore 4.35"
Deck 0"
stroke 3.75"
--Calculated compression ratio = 9.349:1
Rod length 6.768" (440 length)
Intake Closing point @ 0.050 = 41 + 15 per calculator instruction = 56 degrees after BDC.
Dynamic = 7.911.
That should be a cranking pressure of about 156 psi?

The advertised duration numbers look large for that cam? I'm guessing they were measured at 0.002" lobe lift? I think the true intake closing point may be more than the 56 degrees so the DCR and cranking pressure may be lower than the calculated value?




The actual specs of the engine are:

Heads 82cc
bore 4.35
deck .085
piston (flat top) 0cc
stroke 3.75
gasket .027
gasket bore 4.38

I never saw the "add 15*" notation on the calculators I used. But, I found this page however that has a lot of good info and I entered the actual cam numbers into the calculator downloaded from there to figure the exact intake closing.
http://www.chevytalk.org/fusionbb/showtopic.php?tid/92966/

Based on that it turns out to be 71*, which yields a 6.99:1 DCR

That should be pump gas friendly...it should run good on 87 octane...though it may be a slug...