BMW camshafts refer to the rotating shafts that are connected to the crankshaft via engine belts or gears. The camshafts derive their mechanical power from the crankshaft. The mechanical output of the crankshaft is transmitted and modified by the timing belt and respective pulleys of the shafts. Typically, the pulley of the camshaft is larger than the pulley of the crankshaft. This arrangement makes it possible for the camshaft to rotate at half the rotational rate of the crankshaft. The crankshaft pulley is half the circumference of the camshaft pulley.
Hence, when the crankshaft pulley makes one complete revolution, the camshaft pulley completes only one-half revolution. This is necessary to perfectly coordinate the timing between the pistons and the valves. The exhaust valves and intake valves are operated by the camshafts. Since there are two sets of valves, the camshaft rotational rate must be exactly at one-half value of the rotational rate of the crankshaft. The crankshaft itself merely translates the collective, reciprocating linear motions of the pistons into one coherent rotational motion. This rotational motion is then transmitted to the BMW camshafts.
In turn, the BMW camshafts operate the valves. The valves then convert the rotational motion of the camshafts into reciprocating linear motions that are similar to the motions of the pistons. However, the speed rate of these motions is half as slow as the speed rate of the pistons. This is necessary to properly coordinate the closing and opening of the valves with the motions of the pistons. Most discount BMW camshafts can be purchased online. These camshafts perform as well as OEM camshafts. Purchasing aftermarket camshaft replacements can be conveniently done online.
