Rotary engines (Wankel-style) have 3 rotor faces, each with it's own compression metric. As the rotor turns the spark plug hole sees 3 pressure values that reflect the compression for each rotor face.

One of the easiest ways to test an engine's health is by checking its compression. Testing compression isn't something the average muscle car owner would do every year, but it is a useful tool to ...

A compression test is an essential diagnostic tool for determining the health of an internal combustion engine. By measuring the pressure in each cylinder, you can identify issues such as leaks, worn ...

Besides all of the moving parts and complicated-looking pieces of metal, an engine really only needs four things to run: fuel, air, compression, and a spark. It sounds easy enough, but once there's a ...