This is the correct valve timing for my race cams. A timing sheet is supplied with the cams but if it is lost or missplaced look no further.

Inlet valve: -

Inlet valve opens at approximately 60 degrees BTDC

Maximum lift starts at 99 to 104 degrees ATDC and has 12 degrees of dwell (Dwell is the period it stays on full lift).

Exhaust valve: -

Exhaust valve closes at approximately 60 degrees ATDC

Maximum lift at 102 to 106 BTDC and has 12 degrees of dwell.

Helpfull Advice

When setting the valve timing it is most important that you set the inlet timing correctly before you start on the exhaust. The best method is to only fit one cam at a time. The most important part of the timing is the point that maximum lift is reached. Once you are confident that both cams are set correctly you can fit them both and turn the engine over very slowly by hand to check that both valves do not touch on the overlap. If you shine a flashlight down the inlet tract while turning the crankshaft you can look through the exhaust port and watch the valves pass each other. A minimum clearance of 0.040"is recomended! To check this you can make a checking gauge from a short piece of 1 mm wire (0.040") that can be fed down through the spark plug hole and passed between the valves.


Over a period of time I have modified the inlet cam and it now has 0.020" more lift. On some engines the cam follower can make contact with the cam follower guide on full lift. Please check this out with great care! The rocker arms have a ratio of 1.26 to 1 so you will have more than an extra 0.020" at the valve. You must check the valve to piston for clearamce and the valve springs for becoming coil bound!


There is no high compression piston readily available for the ES2 engine. The 16H piston can be modified by shortening the skirt and machining in the valve pockets. A lot a work for a small gain of perhaps 8 to 1. A good alternative is the BSA B44 Hepolite scramble piston. AE-413 GL is stamped inside. There are two other numbers inside of the piston but I think that one is the casting number, but here they are D7211 and 17791. You will need to machine about 3mm from the cylinder base flange to bring the piston up to the top of the barrel and the pushrods will require shortening by the same ammount. You will also have to make/fit a special 0.750" little end bush. This piston will give you 9.5 to 1. This gives a tremendous improvement if you use it along with my cams!