1. The Valve Train Camshafts, Rocker Arms and Push Rods Presented By - David Smith

2. Objective To familiarize the audience with the purpose and uses of: The valve train The pushrod system Alternatives to the pushrod system New developments in the valve train world

3. Role of the Valve Train Times the opening and closing of the cylinder valves Ensures opening and closing is kept in sync Necessary for any combustion engine

4. Components of the Valve Train (Pushrod System) Rocker Arm Valve Pushrod Camshaft Cylinder Head Springs http://www.oregoncamshaft.com

5. Overhead Cam Systems Positions the camshaft in the head(s) Single overhead cams (SOHC) are found in inline cylinder engines Dual overhead cams (DOHC) are found in V- cylinder type engines

6. Advantages/ Disadvantages of the overhead cam system Creates the possibility for more fuel or exhaust valves More valves = More flow Like pushrod systems, will only be 100% efficient at a specific RPM.

7. New Technologies Honda’s VTEC (variable valve timing and lift electronic controls) Lobes can be enabled/ disabled at different RPM’s Allows for variable timing creates more low and high end RPM power

8. New Technologies cont. Ferrari’s VVT System (variable valve timing) Uses 3D lobes Aggressive lobe profile at one end, opposite lobe profile at the other Blended together in the center to form a varying lobe shape Camshaft moved in and out depending on the RPM

9. Ferrari’s VVT system Varying Lobe Design Camshaft Moves Laterally

10. Conclusion By explaining the components and different types of camshafts that go into a valve train, you now have a more profound under standing of the system and the combustion engine as a whole

11. References http://www.streetracersonline.com http://www.oregoncamshaft.com http://www.hotrodder.com http://auto.howstuffworks.com “If cylinder heads are the heart of an engine, then the camshaft and valve train have to be the brains of the operation.” - www.streetracersonline.com