Engine Valve Train

1
Engine Valve Train

• Jeff Barker

2
Valve Train

• Parts of an engine that move the valves

3
How do the Valves move?

• Camshaft rotates at the same speed as the
  crankshaft.
• Lobes on the camshaft push up rockers as the
  shaft rotates
• Rockers push down and open valves

4
Pushrod Valve Train

• Camshaft located inside the engine
• Rocker arm connected to the camshaft by a
  pushrod.
• More weight
• Smaller engine

5
Single OverHead Cam

• Camshaft is on top of the cylinder in direct
  contact with the rocker arm

6
Double OverHead Cam

• Two camshafts instead of one on top of a row of
  cylinders
• Four camshafts in a V-engine
• Produces more power with additional valves
• Centered spark plug
• Larger engine, more parts to maintain

7
Future valve trains

• Pneumatic valve train used in Formula 1 engines
  to reach 17,000 rpm
• Springs are replaced by pressurized air
• Computer controlled valves?

8
Sources

• http//auto.howstuffworks.com/camshaft1.htm
• abbysenior.com/mechanics/valve.htm
• http//www.swcp.com/mcs-bin/Exp_Image.cgi?img_src
  images/VTrain99/RRockHead2.jpg
• http//en.wikipedia.org/wiki/Four-stroke_cycle
• http//www.supercarsunlimited.com/info/tech/stem/a
  dj22.jpg