Originally posted by Car84:
I often hear ppl say TORQUE, BHP,DISPLACEMENT,RPM
Can anyone explain these terms to me pls.....??
torque is a vector. With the SI unit of Newtons per metre (N/m) it is the measure of the Force exerting itself perpendicular to the radii of the leverage on the engine. In layman terms, it is a measure of the "twisting" strength of the engine.
BHP is also measured in terms of the SI for power, measured in Kilowatts. it measures how much energy is needed over a unit of time to stop the engine that is producing peak power at a certain rpm. it is easier to understand the reference from horsepower, which is the amount of energy produced by an engine per unit time, but the 2 are often used interchangeably as they are minutely different.
displacement measures the capacity of your engine. it is measured in the SI unit of volume which is cm3. how much displacement an engine has is found by finding the cross sectional surface area of one cylinder (A = Pi x radius squared), multiply it by the stroke of the engine (how far up and down a crank pushes the piston) and multiplying this figure by the number of cylinders.
eg, a 4 cylinder engine with a bore 84mm (radius 42 mm) and a stroke of 84 mm would have a displacement of:
Displacement = A x stroke x number of cylinders
= pi x 42 x 42 x 84 x 4
= 1998 cc.
displacement is linked to torque closely as a large cc engine would be able to produce more "twisting" force due to more air and fuel being able to be contained within a large cylinder.
RPM stands for revolutions per minute. so 1000 rpms means that the engine is turning 1000 rounds per minute, 9000 rpms means 9000 rounds per minute etc.
