|THE ENGINE IS THE HEART OF YOUR CAR – CRANKSHAFT AND VALVETRAIN
The engine is the heart of your car, but instead of pumping blood,
the engine pumps air and fuel. The engines main function is to
convert air and fuel into rotary motion so it can drive the wheels
of the car. How does it do that??.... Well let's start with
individual parts of the engine then we will get into the actual
The crankshaft is connected to the pistons via a connecting rod. As
the piston moves up and down in the cylinder it rotates the
crankshaft and converts the straight line motion into rotary motion.
The valvetrain consists of valves, rocker arms, pushrods, lifters,
and the cam shaft. (Shown in above picture in blue, yellow, and
green) The valvetrain's only job is that of a traffic cop. It lets
air and fuel in and out of the engine at the proper time. The
timing is controlled by the camshaft which is synchronized to the
crankshaft by a chain or belt.
Now that we have a general overview of the parts involved let's
talk about what happens. Most automotive engine today is 4-stroke
(or 4-cycle) engines, meaning they have four distinct events which
make up the cycle.