compression ratio
#1
Member
CRAFTSMAN
Thread Starter
Join Date: Feb 2005
Location: Iowa
Posts: 53
compression ratio
can anyone tell how to figure compression ratio without taking the heads off?
I have a sbford 302,stock pistons w/.030 overbore, `78 351W heads w/ 202 intake valves, milled(don't know how much). :?
I have a sbford 302,stock pistons w/.030 overbore, `78 351W heads w/ 202 intake valves, milled(don't know how much). :?
#4
Member
MASTER JOURNEYMAN
Join Date: Feb 2008
Posts: 47
You can buy a compression gauge from an auto parts store that you put in place of the spark plug and bump the engine over. It has a reset on it that locks it in place while you are bumping the engine from the driver seat, or you could have a buddy do it while you watch it. Put it in every cylinder and write it down on paper, then add them all together. Take that number and divide it by the number of cylinders, and you will get a round about compression ratio.
#8
Senior Member
SENIOR BUILDER
Join Date: Feb 2005
Location: LAWTON MI
Posts: 113
Originally Posted by Jordan1984
You can buy a compression gauge from an auto parts store that you put in place of the spark plug and bump the engine over. It has a reset on it that locks it in place while you are bumping the engine from the driver seat, or you could have a buddy do it while you watch it. Put it in every cylinder and write it down on paper, then add them all together. Take that number and divide it by the number of cylinders, and you will get a round about compression ratio.
:shock: All that will get you is an average cranking psi :roll: