engine terms

BASIC ENGINE TERMINOLOGY.

ENGINE CAPACITY: This is a total piston displacement or the swept volume of all cylinders.

BORE: Diameter of the engine cylinder.

STROKE: Distance travelled by the piston in moving from T.D.C to B.D.C is called stroke.

TOP DEAD CENTRE (T.D.C): This refers to the position of the piston is in its topmost position.

BOTTOM DEAD CENTRE (B.D.C): This refers to the position of the piston is in its lowest position.

PISTON DISPLACEMENT: This is the volume swept by the piston is moving from T.D.C to B.D.C. This is also called swept volume.

COMPRESSION RATIO: This indicates the extent to which the charge in the engine is compressed. This is calculated as the ratio of the volume above the piston at B.D.C. to the volume above the piston at T.D.C.

POWER: It is the work done in a given period of time. Doing the same amount of work in a lesser time would require more power.

ENGINE TORQUE: It is the force of rotation acting about the crank shaft axis at any given instant of time.

CLEARENCE VOLUME: The volume of cylinder above the piston when it is in the T.D.C position.

INDICATED HORSE POWER: The power developed inside the cylinder is called indicated horse power.

BRAKE HORSE POWER (HP or BHP): This is the actual power delivered at the crank shaft. It is obtained by deducting various power losses in the engine from the Indicated horse power.