• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

Compression Check

50 Coupe

Active Member
Local time
4:55 AM
Jan 17, 2020
Reaction score
Is it possible to check compression by hand turning the crank using a breaker bar or does it need to be spun up faster via a starter?

(My motor is on a stand and I don't have a starter yet but when I tried turning by hand I couldn't get any readings. However, the timing chain is really stretched, maybe that could be the problem. I will put the new one this weekend.)
I would imagine the engine needs to turn faster than possible using a breaker bar. What you see on the gauge is a culmination of several rotations.
You need a starter in it to spin the motor fast enough to get a proper reading. To much air bleed by to get a reading by hand turning.
If you are just checking condition of rings, valves and head gaskets a leak down tester would work if you have the tools. It wouldn't tell you anything about comp ratio.