Supervee Cam Timing

[T540]

I am working on a late 70's Volkswagen Golf powered Supervee motor.

It has an unknown cam in it which seems to have a 310 degree duration.

Any ideas on what angle to time the cam to.

It is currently set at 100 degrees ATDC max lift on #1 inlet valve and the motor is pretty gutless throughout the rev range.

Any ideas would be greatly appreciated.

Thanks in advance.

[pooch776]

I had a similar dilemma a number of years ago while rebuilding a 1600 Cosworth Super Vee engine for my Argo JM2. Ted Wenz of MWE (now Savannah Race Engineering) recommended setting the number 1 cylinder at TDC on the compression stroke. Next adjust the cam sprocket so the number 4 cylinder (which will be in overlap) exhaust bucket is .020 higher than the intake bucket. Use a small straight edge (I used a razor blade) and a feeler gauge. It worked great for me.

Cheers, Joe

[fletch]

I also set it using the same method and have had very good results.
Fletch
March 79V

[T540]

I found some notes which were done when the engine was stripped down some years ago.

This leads me to believe that the cam was set at 110 Degrees ATDC max inlet valve opening.

I have done this and also marked 106 degrees on the camshaft vernier pulley to allow us to eyeball the cam back to 108, then 106 degrees at the track when running the car which will be next week.

Measuring the difference in bucket heights on the number 4 cylinder was quite difficult and I could not do it.

I also found a number on the end of the cam, 51A 9, although I have been unable to find anything when I Google search that number.

Does this mean anything to anyone?

Will post after next weekend with results.

[T540]

The distributor was sent for a service which revealed a loose/broken spark advance plate as well as a worn bearing.

This was repaired and the ignition timed to 38° BTDC.

Cam timing was set at 110° ATDC.

The motor sounds a lot better and the driver reports it to be pulling well and very lively compared to before.

We may still play with the cam timing by moving it back to 106° in increments and testing it on track.

Thanks to all those who provided input to this.