TERMS CONNECTED WITH I. C. ENGINES:

Bore: The inside diameter of the cylinder is called bore.

Stroke: when the piston reciprocate in the cylinder it has the limiting upper and lower positions beyond which it can not move. The linear distance between the two limiting positions of the cylinder is called Stroke.

Top Dead Centre (TDC): The top most position of the piston towards top end side is called top dead center. But, in case of Horizontal Engines it is known as inner dead center.

Bottom Dead Center (BDC): The lowest position of the piston towards crank end side is called Bottom dead center. But, in case of Horizontal Engines it is known as outerdead center.

Clearance Volume: The volume contained in the cylinder above the top of the piston when piston is at the top is called Clearance Volume.

When L = D - Called Square Engines

When L D - Under Square Engine

Swept Volume: The volume swept by piston between between top and bottom dead center is called swept volume / piston displacement.

Compression Ratio: It is ratio of total cylinder volume to clearance Volume.

Compression ratio (r) = Vs + Vc / Vc

Piston Speed: The average speed of the piston is called Piston Speed & = 2LN where L = Stroke of Piston & N = RPM of engine.

Average engine speed of engines is 5 to 15 m/sec. ( This speed is kept in this range Because of – strength of material& noise consideration.

Direct Injection: Fu el injected to the main combustion chamber of an engine.

Indirect Injection: Fuel injected to the secondary combustion chamber of an engine.

Smart Engine: The Engines made with computer controls that regulate operating characteristics such as air-fuel ratio, ignition timings, valve timings, intake tuning and exhaust control.

Air fuel Ratio: It is ratio of the mass of Air to mass of Fuel.