1. Engine Top End Construction
Chapter 13
Engine Top End
Construction

2. Contents Cylinder head construction Valve train construction
Intake manifold construction
Exhaust manifold construction

3. Engine Top End
Includes the cylinder head, valve train, valve cover, and intake and exhaust manifolds

4. Cylinder Head Construction
A bare cylinder head is a head casting with all of its parts removed
If a cylinder head becomes damaged, the technician may need to install a new bare head
All the old, reusable parts can be removed and installed in the new head

5. Cylinder Head and Parts

6. Cylinder Head Construction
This cast aluminum head has four-valve combustion chambers

7. Cylinder Head Construction
This cast iron head has two-valve combustion chambers

8. Valve Guide Construction
There are two basic types of valve guides:
integral valve guides
pressed-in valve guides

9. Integral Valve Guide Part of the cylinder head casting
Simply a hole machined through the cylinder head
Very common because of its low production cost

10. Pressed-In Valve Guide
Separate sleeve forced into a hole machined in the cylinder head
Made of cast iron or bronze
During repair, a worn guide can be pressed out and a new guide can be quickly pressed in

11. Valve Seat Construction
Valve seats can be integral or pressed-in
Integral valve seat
machined portion of the cylinder head casting
Pressed-in valve seat
separate part that is forced into a recess cut into the head
commonly used in aluminum heads

12. Valve Seats and Guides

13. Valve Seat Angle Angle formed by the face of the seat
Most engines use a 45º angle
Some high-performance engines use seat angles of 30º