Required Tools & Parts:
- Feeler gauge
- Flat blade Screwdriver
- Starting handle or large spanner
- Rocker cover gasket
- Gasket Sealant
Setting the Valves
The Valve adjustments should be made with the engine cold. The importance of correct rocker arm/valve stem clearances cannot be over stressed as they vitally affect the performance of the engine. If the clearances are set too open, the efficiency of the engine is reduced as the valves open late and close earlier than is intended. If on the other hand the clearances are set too close there is a danger that stems will expand upon heating and will not allow the valves to close properly which will cause burning of the valve head and seat and possible warping.
If the engine is in the car to get to the rockers it is merely necessary to remove the holding down studs from the rocker cover, then lift the rocker cover and gasket away. It is important that the clearance is set when the tappet of the valve being adjusted is on the heel of the cam, (ie the opposite peak). This can be effected by carrying out adjustments in the following way, where Valve 1 is at the front of the engine:
Valve fully open Check and Adjust
Valve No 8 Valve No 1
Valve No 7 Valve No 2
Valve No 6 Valve No 3
Valve No 5 Valve No 4
Valve No 4 Valve No 5
Valve No 3 Valve No 6
Valve No 2 Valve No 7
Valve No 1 Valve No 8
This principal is more commonly known as the rule of 9, where each adjustment should add up to 9 (ie 7 plus 2 = 9).
The correct valve clearance of .012in (.306mm) is obtained by slackening off the hexagon lock-nut with a good fitting spanner whilst holding the ball pin adjuster against rotation with the screwdriver. Then while still pressing down with the screwdriver, insert the feeler gauge in the gap between the valve stem head and the rocker arm and adjust the ball pin until the feeler gauge will just move in and out without any nipping. Then still holding the ball pin in the correct position, tighten the lock-nut. Repeat this process for each valve set, you can use the starting handle to turn the engine to the next valve required for setting. (NOTE: make sure the ignition is off when doing this).
Once you have re-set all the valves you can replace the rocker cover with a new gasket. It can be an idea to use some gasket sealant when attaching the rocker cover gasket to the rocker cover, this will help to hold it in place when you come to fit it. It is also helpful to use a small amount of general purpose grease to help seal the gasket to the engine.