Just to finish this off I decided to explore the current set up before taking things apart. Yes, rare, isn't it?
I bothered to make reasonably accurate marks on the mag coupling and timing case to indicate TDC. It's a bit small diameter but there's not much else to work from.
Using a clever modern timing light with advance adjustment I ascertained that the distributor on the car was not advancing correctly and was giving 38 advance in crank degrees!
I took it apart and the plate (10 cam degrees) wasn't worn but the weights and springs were not doing their job. Weights replaced and two decent light springs put in place. I timed it using the clever timing light to give 20 degrees of advance at 2,000 rpm and the result is very satisfactory. It goes so much better and keeps cooler.
The lesson is pay attention to the distributor advance mechanism.
I bothered to make reasonably accurate marks on the mag coupling and timing case to indicate TDC. It's a bit small diameter but there's not much else to work from.
Using a clever modern timing light with advance adjustment I ascertained that the distributor on the car was not advancing correctly and was giving 38 advance in crank degrees!
I took it apart and the plate (10 cam degrees) wasn't worn but the weights and springs were not doing their job. Weights replaced and two decent light springs put in place. I timed it using the clever timing light to give 20 degrees of advance at 2,000 rpm and the result is very satisfactory. It goes so much better and keeps cooler.
The lesson is pay attention to the distributor advance mechanism.