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Shrink-fit Tubing

An insulated tubing that shrinks to about half its original diameter when heated.

Shrinking Hammer

A special hammer that is used to shrink spots that have been stretched by excessive hammering.

Shroud

1. A metal or plastic duct that directs ambient air to the radiator cooling fan. 2. A hood-like device placed around an engine fan to improve air flow.

Shrouding

An obstruction, such as carbon buildup, around a valve in the combustion chamber that interferes with the proper air flow.

Shunt

1. A British term for vehicle accident. 2. To bump or shove another car in an oval track or road race. 3. A parallel electrical connection or circuit.

Shunt Winding

Bypass winding found on some alternators.

Shut Down

1. To defeat a competitor. 2. To stop an engine.

Shut Down Valve

A valve which is used to shut down an engine by interrupting the fuel supply; a safety requirement for many competitive vehicles.

Shut Off

To slow a vehicle by releasing the accelerator or throttle.

Shut Off Area

An area beyond the measured distance of competition where the vehicle may be safely brought to a stop.

Shut The Gate

1. To pass a competitor in closed-course racing then immediately cut in front. 2. To prevent an opponent from passing on the inside of a turn by blocking the apex.

Si

[1] Silicon An element with the atomic number of 14 [2] An abbreviation for spark ignition [3] An abbreviation for systems Internationale des Unites a scientific unit of measurement.

SIACM

Acronym for Side Impact Airbag Control Module (Chrysler).

Siamese

1. To exhaust pipes joined together. 2. Cylinders in an engine block that are cast co closed together that there is no room for a coolant passage between them. 3. Two adjacent valves in a cylinder head that is served by a single port.

Siamese Ports

Intake or exhaust ports inside the cylinder head where two cylinders are feeding through one port.

Side Bolt Mains

Side-mounted main bearing bolts that increase the rigidity of the lower end.

Side Clearance

The clearance between the cheeks of the crankshaft journal and the connecting rod.

Side Gears

Bevel gears that transfer power from the differential pinion gears to the splined axle shafts, providing differential action during turns.

Side Guard Door Beam

The structural member of a vehicle door that prevents it from being pushed inward if struck.

Side Lead

The effects of centrifugal force as a vehicle rounds a turn.