Compression ratio calculators??
 

I've used a few different sites that come up with 3 different numbers.
Specs are 3.484 bore, 3.976 stroke, 10.2 cc dome, deck height 0, gasket thickness .074
gasket bore 3.51. Cylinder head volume 48 cc's
The sites I've found vary by as much as 2 full points (13 to 1 up to 15 to 1) Using the same input data (some of the sites don't ask gasket bore size) I would think it shoulkd be within half a point.

Re: Compression ratio calculators??
 

You have a PM
You have more than enough

Re: Compression ratio calculators??
 

Art, did you try Wallace Racing calc?

http://www.wallaceracing.com/cr_test2.php

Re: Compression ratio calculators??
 

I find this site is real simple for numerous race calculations:
http://users.erols.com/srweiss/index.html

Re: Compression ratio calculators??
 

What gets me is I get 15.70 on one site 14.62, 16.30 on another
This is with putting the same numbers in Some take in to account the head gasket bore others don't. But it shouldn't come to 2 full points. I think there is a formula in an old rule book I can do on paper.

Re: Compression ratio calculators??
 

Artie,make sure you bolt that hood down good and tight.............................................

Re: Compression ratio calculators??
 

Ed I have my front mounted parachute on that hood

Re: Compression ratio calculators??
 

Art,
I think there is a formula in both the How to Build Books. Both Small Block and Big Block. I have it on my shop computer and will PM it to you tomorrow. It will come out with in a .00 of what I sent you.
Adger

Re: Compression ratio calculators??
 

Useing your info. Above i got 13.540:1, normally aspirated at sea level........this is an older computer program i use with sprint car
motors.

Re: Compression ratio calculators??
 

I'm going to run the motor the way it is. But I was perplexed at the variation in the different programs. I wonder if the calibations are done by nhra in different divisions LOL.