compression ratio
Thread Starter
Racer
Joined: Jul 2009
Posts: 350
Likes: 7
From: springstead wi
compression ratio
how can i find out what mine is . last time i did a compression test it was 219 +- . im decked out 40 bored 30 over and have 64cc dart heads and double eyebrow domed pistons .
Le Mans Master
Joined: Apr 2007
Posts: 7,353
Likes: 72
From: Graceland in a Not Correctly Restored Stingray
Depends directly on just how much dome volume. Were your pistions off-the-shelf, and if so do you recall the brand? That info might get us close to an educated guess.
FWIW, if that 219 is your cold cranking pressure, your DCR may likely be on the high side for pump gas, and might indicate you could increase your cam's duration...
FWIW, if that 219 is your cold cranking pressure, your DCR may likely be on the high side for pump gas, and might indicate you could increase your cam's duration...
Race Director
Joined: May 2006
Posts: 18,734
Likes: 2,582
I do not think it can be accurately done on an assembled engine. Below is a link to some formulas
http://www.greatplainsas.com/icompratio.html
http://www.wiseco.com/Calculators.aspx
http://www.greatplainsas.com/icompratio.html
http://www.wiseco.com/Calculators.aspx
Last edited by MelWff; Mar 25, 2010 at 01:28 PM.
Thread Starter
Racer
Joined: Jul 2009
Posts: 350
Likes: 7
From: springstead wi
i found the box they came in they were speed pro forged there number 7070p .30 over but cant find any info on them . i thought they were domed but i could be wrong . did find something that said the flattop with eyebrows were 10.2to1
