The crankshaft is a rotating shaft that converts the reciprocating motion of the pistons into rotational motion. The crankshaft is located at the bottom of the engine and is connected to the flywheel. The flywheel stores energy and helps to smooth out the power delivery of the engine. The crankshaft is made of steel and is typically heat-treated to improve its strength. The camshaft is a shaft that controls the opening and closing of the valves. The camshaft is located in the cylinder head and is driven by the crankshaft. The camshaft has a lobe for each valve. The lobe pushes on the valve tappet, which opens the valve. The camshaft is made of steel and is typically heat-treated to improve its strength. The fuel injector injects fuel into the cylinder. The fuel injector is located in the cylinder head and is controlled by the electronic control unit (ECU). The ECU determines the amount of fuel to be injected based on the engine speed and load. The fuel injector is made of a special material that can withstand the high temperatures and pressures.