can you find out your CR from PSI of a compression test?
12-14-2010, 12:41 PM
#1
can you find out your CR from PSI of a compression test? Is there a chart somewhere that will give you a compression ratio for certain PSI of a compression test?
May like 155psi is 8.5 to 1 or a ball park?
I would like to know the true compression ratio of this motor. People call me crazy when on paper it is 12- 12.6 to 1.
May like 155psi is 8.5 to 1 or a ball park?
I would like to know the true compression ratio of this motor. People call me crazy when on paper it is 12- 12.6 to 1.
12-14-2010, 12:53 PM
#2
Moderator
iTrader: (11)
Join Date: Mar 2002
Location: East Central Florida
Posts: 12,604
Likes: 0
Received 6 Likes
on
6 Posts
You can get "static compression ratio" but that will not
relate very well to physical CR if you have any cam
overlap.
Pressure/14.7 = CR-1, or something like that. I forget.
But I'd think a CR tester would read directly.
I built a 307 with 305 heads once and it blew the cheapo
compression tester out of the hole. If you're pushing 12:1
then you want a hard threaded one.
relate very well to physical CR if you have any cam
overlap.
Pressure/14.7 = CR-1, or something like that. I forget.
But I'd think a CR tester would read directly.
I built a 307 with 305 heads once and it blew the cheapo
compression tester out of the hole. If you're pushing 12:1
then you want a hard threaded one.
