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 is served by four valves. To help achieve the required gas-flow characteristics, these are arranged asymmetrically around the cylinder bore. 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 dimensions.
| ITEM | DESCRIPTION |
|---|---|
| 1 | Exhaust valves |
| 2 | Fuel injector location |
| 3 | Spark plug location |
| 4 | Inlet 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 ensure that each spark plug is orientated in the cylinder correctly.
The benefits of this are optimum spark plug intrusion into the combustion chamber to improve combustion, idle stability, dilution tolerance and spark plug durability. The spark plug must be tightened to the specified torque to ensure the correct 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 the orientation is as marked on the cap.
A camshaft cover is fitted and sealed with a rubber seal and 3 smaller rubber seals. The cover is retained in position with 15 bolts which are located through a sleeve and a grommet for sealing and a single stud and nut.