Igneous Rock is formed when a magma cools underground and crystallizes or when it erupts unto the surface of the ground, cools and crystallizes. Magma that erupts onto the surface is called lava. When magma cools slowly underground the crystals are large enough to see.
Readings for compression tests usually vary between 175 to 250 PSI (Pounds per Square Inch). A higher reading generally indicates better engine performance; however you should check your vehicle manual to find out what the ideal reading should be for your vehicle.
Today we are going to cover the different types of fittings for compression testing on both automotive and diesel engines. Compression testing is one of the easiest way to check an engine to try and locate an internal problem by testing each cylinder against each other and what your service manual recommends as an acceptable reading for that engine.