Compression Ratio Fromula

[carguy1959]

Does anybody know how to convert compression psi to ratio? I did a compression test on my 400 sbc today, it read 190 to 195 on all cyl\'s....

[wickeds10]

thats damn good cause ur making good power still with the rings holding that tight ..... u probably have no leaks past them rings

[s15laynrubba]

Does anybody know how to convert compression psi to ratio? I did a compression test on my 400 sbc today, it read 190 to 195 on all cyl\'s....



I don\'t think its possible to tell the ratio from a compression test.If you know the specifics of your engine, just follow the links below.....Jay



http://members.uia.net/pkelley2/crc.htm

check out the DCR calculator (http://cochise.uia.net/pkelley2/)

[carguy1959]

The spec sheet on the pistons said my compression with 70cc heads (thats what I got) would be 10.3. I took those heads off last night and am in the process of putting the stock 76cc heads on. I\'m trying to lower my compression. I drive my truck to work alot, 70 miles round trip. Would like to get it to where I can run regular unleaded. The sheet says that with 76cc heads my compression should be 9.8.....

[BrandOmatic]

There was also an article in the august 2003 issue of \"Super Chevy\" about how to measure your exact compression ratio. Quite the lengthly process. Lots of measurements to be taken. Looked to be way over my head, hah..