BA Brake assist

Bottom dead centre

BEV Battery electric vehicle

BIW Body in white

BHP Brake horse power

BSFC Brake specific fuel consumption

Birmabright was an aluminium alloy containing magnesium.

Birmabright was developed by the Birmingham company Birmetals and was used for the bodywork of the original Land Rover, and other Rover vehicles produced in the 1950s.

Today a similar material is known as NS4 or 5251 alloy.

The bead is the reinforced inner edge of a tyre, where the tyre meets the wheel rim.


Bottom dead centre (BDC) is when the piston in a reciprocating engine is at its lowest point.

In a four-stroke engine, each piston reaches bottom dead centre twice during the engine cycle - once at the start of the compression stroke, and again at the start of the exhaust stroke.

Valve timing is often expressed as degrees before or after BDC (BBDC and ABDC respectively).

See also top dead centre (TDC).

A bucket tappet is a tappet or cam follower in the shape of an upturned bucket, placed over the end of the valve stem.