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Counter Bored Ring

A compression piston ring with a counter bore on its inside diameter to promote cylinder sealing.

Counter Emf

Induced voltage; the voltage opposing the applied voltage and the current in a coil, caused by a flow of current in the coil.

Counterbalance

A weight added to a rotating shaft or wheel to offset vibrations.

Counterboring

A machining process, related to drilling, using an end-cutting tool to concentrically enlarge a hole to a limited depth.

Counterclockwise (CCW)

A rotation to the left; as opposed to the direction of the rotation of clock hands.

Counterclockwise Rotation

Rotating in the opposite direction of the hands on a clock.

Counterelectromotive Force

[1] A term used for back emf or counter emf. [2] An induced voltage that opposes the source voltage

Countergear

An integral cluster of three or more various-sized gears, located in the lower transmission case, that revolve on a countershaft to provide the desired gear ratios, usually for second, low, and reverse.

Countershaft

1. A shaft used in a V-8 engine to reduce the effects of imbalance. 2. Two shafts used in an I-4 engine to reduce the effects of imbalance. 3. The shaft that supports the cluster-gear set in a manual transmission and rotates in the opposite direction of the clutch and driveshaft.

Countersinking

A machining process, related to drilling, that bevels or recesses the material around the circumference of a hole.

Counterweight

1. A weight that is cast opposite each offset connecting-rod journal to provide the necessary balance. 2. A weight that is added to a rotating shaft or member to offset vibration by balancing the part.

Counts

Numerical value given to movement increments or steps of a digitally controlled output, such as the idle air control value

Coupe

Usually a 2-door car with a fixed roof (as opposed to a convertible). However, 2-door cars sometimes are called sedans; these vehicles usually have a pillar, or post, between the driver's (and passenger's) side window and the quarter window. Vehicles without the pillar sometimes are referred to as hardtops.

Coupe (cpe)

A car with a close-coupled passenger compartment.

Coupe De Ville

A coupe with an open driver compartment and enclosed passenger compartment.

Coupling

An attachment where one mechanism or part drives another mechanism or part, to follow the movements of the first.

Coupling Phase

The point in torque-converter operation where the turbine speed is 90% of the impeller speed, and there is no longer any torque multiplication.

Coupling Stage

A term referring to the torque-converter turbine speed, as it closely approaches the impeller speed; occurs during higher speeds under light loads.

Coupling Yoke

Two integral or separate Y-shaped components to which the universal-joint bearing cups are attached.

Coupon

1. A piece of metal, of specified size, used for testing. 2. A piece of metal from which a test specimen may be prepared.