Cylinder Heads
The cylinder heads are manufactured in gravity die cast aluminum alloy and are unique for each cylinder bank. Deep-seated bolts reduce distortion and secure the cylinder heads to the cylinder block.
Each cylinder has 4 valves to help achieve the required gas-flow characteristics. Each cylinder has a centrally mounted fuel injector and spark plug.
The valves are a conventional arrangement, with a valve and spring assembly retained by a valve collet. The valve tappets are graded and selected on assembly to obtain the correct valve clearance.
| ITEM | DESCRIPTION |
|---|---|
| 1 | Exhaust valves |
| 2 | Spark plug location |
| 3 | Fuel injector location |
| 4 | Intake valves |
The cylinder head gasket is of a multi-layer steel construction.
The threads for the spark plugs are machined at a precise start point to make sure that each spark plug is positioned correctly in the cylinder. The benefits of this are optimum spark plug intrusion into the combustion chamber to improve combustion, idle stability, dilution tolerance and spark plug durability. Precise torque tightening of the spark plugs is essential to provide the correct spark plug orientation.
The camshafts run on line bored journals in the cylinder head and camshaft caps. Therefore it is very important that the camshaft caps are maintained with their respective journal and their orientation as marked on the bearing cap.
A camshaft cover is secured and sealed with an external rubber seal and 3 smaller inner rubber seals. The cover is retained in position with 15 bolts and 1 stud and nut arrangement and located through sleeves and rubber washers.