- R -

Radiofrequency Interference

Radio and television interference caused by electromagnetic energy.

Radius

A line extending from the center of a circle to its boundary.

Radius Arms

Longitudinal suspension arms used to position a beam axle.

Radius Ride

A condition where the crankshaft rides on the edge of a bearing.

Radius Rods

A term used for radius arms.

Radiused

1. A procedure that is used to reduce the radius diameter at the area the valve stem meets the valve head. 2. A valve type that is ground with a radial grinder to aid in air flow around the valve. 3. Wheel wells that have been cut into a circular shape.

Radix

1. A base. 2. The base number in a number system.

Rag Top

A convertible.

Ragged Edge

The absolute limit of a vehicle's potential.

Rail

An early dragster with exposed frame rails.

Rail Job

A term used for rail.

Rake

A suspension or structural design to lower one end of the vehicle in relation to the other end.

Rally

A sports-car driving contest for driver performance as opposed to vehicle performance.

RAM

[1] an acronym for Random Access Memory a computer read-write memory on which information can be written and from which it may be read from.

Ram Air

Air forced through the radiator and condenser coils by the movement of the vehicle or the action of the fan.

Ram Air Cleaner

An air cleaner for high-performance cars that opens an air scoop on the hood to provide a ram effect when the throttle is wide open.

Ram Induction

An intake manifold designed to cause a resonant effect at a specific predetermined engine speed.

Ram Tubes

Short, tuned, tubular stacks on the top of carburetors.

Ram Tuning

The tuning of an intake manifold to ensure that the passages are of sufficient length to cause a resonant effect at a specific predetermined engine speed.

Ramp

The sloping section of a camshaft lobe which raises the lifter.