06-07-2012, 04:47 PM
Valve Train
Valve Train.ppt (Size: 1.04 MB / Downloads: 98)
INTRODUCTION
Internal combustion engine is a AIR PUMP.
MORE AIR - MORE POWER.
Cam grind determines Performance.
Cam grind determines driveability characteristics.
Cam Drives
CAM DRIVES
The Camshaft is Driven by the Crankshaft.
Cam is driven at one half Crank speed.
Cam Gear has twice as many teeth as crank gear.
GEAR DRIVES
Cam gear is soft - Fiber or Aluminum
Are press fit to cam - Pre-heat to 200 degrees to install.
Crank gear - Steel
Advantages - Less wear and Backlash
Disadvantages - Takes more space and can be noisy.
TIMING BELTS
Cogged Belt Drive.
Advantages Lighter, Quieter, Easier to Change.
Virtually no stretch in service.
Watch rib tooth shape - Rounded or Square.
Replacement 30,000 to 60,000 miles.
CAM MEASUREMENTS
Lift - Valve & Cam - Measured in inches.
Duration - Measured in degrees of crank rotation.
Overlap - Both intake & exhaust valves open.
Split Overlap - Both valves open equally at TDC.
Centerline - Point of maximum opening