1. Automotive Engines Part 6 (Valvetrain)

2. Valvetrain The collection of parts operate the valves. The Valvetrain includes the various parts that convert the camshaft's rotary motion into reciprocating motion at the valves, and the valves and their associated parts. These parts include:

3. Valvetrain 1. Cam 2. Lobe 3. Lifter 4. Push Rod 5. Rocker Arm 6. Valve 1 2 3 4 5 6

4. Valvetrain Parts Cont. Seals, Retainers/Rotators, Keepers Rocker Arms, Followers, Push Rods Guides, Seats, etc.

5. Cyl. Head Parts Guides Seats Valves Springs Cups (Al. Heads) Retainers Seals Keepers Rockers

6. Valves Made of: – Steel – Stainless – Titanium

7. Valve Spring Generally a coil of wire, that closes the valve after it has been opened by the cam, and prevents the valve from bouncing on its seat.

8. Valve Retainer/Rotator Retainer – Connects Valve to spring Rotator – Rotates Exhaust Valves to eliminate hot spots

9. Valve Spring Keepers Cone shaped wedges hold retainers to valves

10. Rocker Arm A reciprocating lever, generally used to multiply valve lift

11. Follower (OHC) 1. Follower: Similar to a Rocker Arm 2. Lifter 3. Valve 4. Lobe 1 2 3 4

12. Shim & Bucket (OHC) Cam Acts on Valve Shim is removable Adjusts lash

13. Pushrods Transfer lifter motion to rocker arm. Most are hollow to transfer oil to valves & rockers.

14. Valvetrain – The End