In the dark days of engine-building, car crafters had to rely on a compression tester to tell them if they had a weak cylinder by comparing the cranking pressures of the cylinders against each other.

The purpose of your engine is to compress fuel and air and then ignite it, creating heat energy that then makes mechanical motion. If your engine can't compress the air and fuel properly, the ...

Compression test kits do just what they say: measure the ability of each cylinder of your engine to combust the fuel/air mixture without losing any of the resulting energy. While they're not as ...

Mityvac’s compression tester is unique in this list for including an air-hold adapter that you can use to effect valve seal repairs without having to remove the engine’s cylinder head.

A compression test reveals the condition of your engine's valves, its valve seats, and piston rings and whether these parts are wearing evenly. Healthy engines should have compression over 100 psi ...

on the compression tester's gauge. Make sure to count the number of engine revolutions it takes to reach max pressure and repeat the test for each cylinder, cranking the engine the same number of ...

If one or more cylinders has a good deal less pressure ... If you can't find the right fuse and you want to do a compression test anyway, be especially careful. 4. Before you remove them, label ...

You can check if it's piston rings by running the compression test with a little oil in the cylinders. This "wet" compression test basically plugs up any wear passage between the rings and the ...

A better name might be cylinder-pressure test. A rough estimate of cylinder pressure is 15 to 20 times the compression ratio. So 10:1 should produce about 150 to 200 psi. Production-engine ...