Saturday, 8 October 2011

9. Fitting the oil pump drive, bypass and pressure release valves.

We  are now going to fit the oil pump drive.
There are 2 different size oil pumps. pre 1960 it was a small pump and post 1960 a larger pump.
Both sizes of gasket are provided in the kit. Choose the correct size of gasket and make sure the surface of the pump and third part are clean. Use some assembly grease on the gears.

Oil pump assembly. Check the drive key (red arrow) is in good condition and replace if not.

Gears in place in third piece and coated with white assembly grease (early 4 stud small pump).

Fit the correct gasket - there is only one correct way for the gasket to fit so make sure it is lined up properly and fits over the studs. No flange sealant is required and as you rotate the flywheel push the pump onto the studs until the key locates in to the end of the cam and the pump sits flush.
The later pumps are held in place by one long bolt and 3 nuts. Use red loctite on the nuts and threads of long bolt which goes in the bottom left hole. The earlier small pumps had four studs.
Pop on the washers and tighten evenly starting with the bolt on large pumps.  These should be torqued to 10 ft lbs. Turn the engine occasionally awhile tightening the nuts to make sure nothing is binding.

Installing the oil pressure relief and bypass valves.

Oil pressure relief / bypass valves.

There are 3 different set-ups for the valves.

Up to mid 1957

Early engines to the mid 1957 period had just one combined relief/bypass valve. The spring of this one should have 15 turns. Fits into the third piece as in picture below.

The arrow points to the valve position in the third piece

Mid 57 to 1963 

These engines have one relief valve and one bypass valve. Superficially they look the same but the springs are different. 
The oil pressure relief valve is placed in the left case half pointing horizontally and the spring is made of thicker wire. It generally has about 13 coils.

The oil bypass valve fits in the third piece similar to the earlier engines and has a thinner spring with about 17 coils or turns on the spring. It is also shorter.
Do not get them mixed up!

Post 1963 

Both the relief valve and the bypass valve are now identical and so are interchangeable. Use the best plunger for the oil pressure relief valve in the left hand case.


Take the copper washer / "O" ring from you gasket set.  Make sure the seam which is on the face of the  washer is facing away from the case and towards the head of the threaded nut..

Clean out the case passageways with WD 40.

Clean the parts with WD 40 and then put a little engine oil onto the spring and plunger. Put into position and tighten up with a large screwdriver.

Give it a final tighten with a vice grip. Use an old cloth to stop the jaws damaging the head of the bolt.

Oil pressure relief valve and bypass valves on a post 1963 engine. They are identical and by this stage were interchangeable. Not so for earlier engines.

Seam on copper washer  / "O" ring should face towards the head of the bolt.

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