A refrigeration system’s compression or pressure ratio is defined as the absolute discharge pressure divided by the absolute suction pressure. Calculating this ratio can be a big help when it comes to ...

A gasoline piston engine that can dynamically change its compression ratio —that is, the amount by which the piston squeezes the fuel-air mixture in the cylinder—has long been a holy grail of engine ...

Lead is put in gasoline to prevent knock, i.e., to permit the last part of the air-fuel mixture to burn to withstand higher pressures and temperatures before auto-igniting. The ability to withstand ...

One of the key variables for an internal combustion engine is its compression ratio. This is the ratio of the maximum volume within the cylinder (when the piston is at bottom dead center) and the ...

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 per ...