ENGINE COMPONENTS
Engine Block
As you can see by the illustration, the engine block is the housing for the pistons,
crankshaft, connecting rods, oil pump, and camshaft (to which everything else is
attached).
Crankshaft
The crankshaft is considered the backbone of the engine. It is formed out of steel
and shaped into various parts. There are also counter weights (to keep the shaft
spinning) and journals (smooth surfaces on which the bearings ride). The pistons
are connected to the crankshaft by connecting rods. Consequently, as the
crankshaft turns, the pistons go up and down. It’s this action that produces the
strokes in the four-stroke cycle. The crankshaft rides on bearings that provide a
smooth lubricated surface. This surface enables the crank to spin at the high
speeds necessary for the engine to function.
Pistons
Pistons are cylindrically shaped metal pieces (plug-shaped) that move up and
down in a cylinder. The expanding pressure in the cylinder, produced by the
explosion of the air-fuel mixture ignited by the sparkplug, causes this vertical
movement of the pistons.