Engine Identification and Inspection

Cubic Inch Displacement Formula

3.14 * bore^2 * stroke * number of cylinders / 4

Combustion chamber

Area between the piston and cylinder head when the piston is at the top of its stroke

Multi-Position Crankshaft

Can be used at any angle Chainsaw; Weed Eater

A Two-stroke cycle engine

Carburetor may be located at the base of the cylinder or the bottom or side of the crankcase

A four-stroke cycle engine

Carburetor will always be on or near the cylinder head

Cycle

Completion of a series of events to produce a power impulse

A four-stroke cycle engine

Compression resistance is felt every other revolution

A Two-stroke cycle engine

Compression resistance is felt every revolution

Horizontal Crankshaft

Crankshaft lays horizontally

Vertical Crankshaft

Crankshaft on bottom, lawnmower

A Two-stroke cycle engine

Does not have an opil sump and oil filter

Two-stroke cycle engine

Engine design permiting a power stroke once for each revolution of the crankshaft

Four-stroke cycle engine

Engine design which develops a power stroke every other revolution of the crankshaft

A four-stroke cycle engine

Exhaust muffler connects at the head of the engine cylinder

A Two-stroke cycle engine

Exhaust port is about midpoint on the cylinder

Crankcase

Housing for the crankshaft and other related internal parts

Nameplate

Information plate attached by the manufacturer giving their name, the engine make, model, serial number, and other information

Intake port

Opening into the combustion chamber for the intake of the fuel-air charge

Exhaust port

Opening to the outside of the combustion chamber for the release of exhaust gases

A four-stroke cycle engine

Usually has oil sump and possibly and oil filter

Model numbers

describe the basic engine

The type number

describes the varations of the engine and these numbers are required when ordering parts

The code number

indicates the date the engine was built and assembly line number making the engine