1. CAMSHAFT, ROCKER ARMS, PUSHRODS (VALVE TRAIN)
MICKEY HO
4M – D

2. CAMSHAFT Lobes (Key component) Arrangements
Controls opening and closing of intake and exhaust valve
Timed with motions of piston in cylinder
Arrangements
Single overhead cam
Double overhead cam
Pushrod

3. Timing for Intake and Exhaust

4. SOHC and DOHC SOHC – one cam per head DOHC – two cam per head
Cam controls both intake and exhaust
DOHC – two cam per head
Intake and exhaust each has a cam
Four or more valves per cylinder
Advantage
Disadvantage
Higher engine speed
Breakage in timing belt/chain

5. PUSHROD Camshaft inside engine block Uses pushrods to control valves
Less prone to breakage
Limit engine speed

6. REFERENCE http://auto.howstuffworks.com/camshaft.htm