1. Overhead Cam 4 Cylinder Internal Combustion Engine MAE 388 12/13/05 Joel Mermoud Ted Young June Pak Babarinde Makanjuola

2. Rotating Assembly

3. General Functions of the Rotating Assembly Components The upper and lower blocks house the rotating assembly and create the foundation for the engine. Rotation of the crankshaft forces the piston and connecting rod assembly to move up and down in the cylinders of the engine block. The upward and downward motion of the pistons create compression and vacuum within the cylinders, respectively.

4. Cylinder Head Assembly

5. General Functions of the Cylinder Head Assembly Components The cylinder head casting creates the foundation for the cylinder head assembly. Within the casting are the intake and exhaust ports, the valve guides and the combustion chambers. A cylindrical surface is created by the combination of the cylinder head and the rocker block, in which the cam shaft is free to rotate. The rocker arms rotate about a rocker shaft that is secured to the top of the rocker block. The rotation of the rocker arms are constrained by the geometry of the cam lobes. Rotation of the camshaft causes the rocker arms to move the valves up and down. The opening of the intake valve permits flow of an air/fuel mixture through the intake port into the cylinder. The closing of both valves allows this air/fuel mixture to be compressed. The opening of the exhaust valve allows expulsion of the exhaust through the exhaust port.

6. Operation Each cylinder experiences four cycles for every two rotations of the crankshaft: –Intake, Compression, Power, and Exhaust –Explosion of the air/fuel mixture during the power stroke provides the energy required to run the engine and perpetuate this cyclic process –These events are timed so that the cylinders fire in succession

7. This project was based on a scale model which came with an electric motor assembly to run the engine. Attached to the rear of the engine, its driven gear engages the flywheel and rotates the engine.