Glossary: Engine Blocks and Cylinder Heads

A calibrated leakage of fuel around the nozzle valve intended to lubricate and cool the valve.

A rotating shaft having an eccentric weight that is used to offset torsional vibration produced by an engine.

The voltage drop (or pressure differential) measured across the P–N junction that is typically between 0.3–0.7 volts in bipolar diodes. A minimum voltage at this level and above is required to forward bias a diode—or to get it to conduct current.

The raw mineral oil processed from crude oil.

The rate at which serial data is transmitted.

The point in the combustion cycle, measured in degrees of crank angle rotation, when fuel is injected into the combustion chamber of a diesel engine.

The electronically detected point in the combustion cycle when the solenoid poppet valve is closed.

The creation of a low-pressure area by the increased velocity of air (or a fluid).

Two-way MUX communication over a communication channel between an electronic service tool and a vehicle network, where commands are sent and data is received by the service tool.

A fuel treatment that kills microorganisms.