Lucas Auto Advance Distributors

[andrew34ruby]

I did the same as Graham. The holes and the pins were both slightly worn, so having first welded up the holes I filed them out bit by bit until the correct advance had been reached. I was surprised how much difference it made to the running of the car.

Peter, it would be useful to know, when the holes and pins were worn was the timing when under power too far advanced? Or not sufficiently advanced?

Thanks

[Chris KC]

Interesting Charles, thanks for sharing.

Am I correct in understanding that your present set-up gives 20 crank degrees at 2000rpm, and that this is the max amount of advance? And are you still happy with it? (Do you plan to experiment further?)

And the original unit before repair - I would guess with tired springs, advance comes in too quickly? - and with worn holes, too much? Have I understood correctly?

[Charles P]

Interesting Charles, thanks for sharing.

Am I correct in understanding that your present set-up gives 20 crank degrees at 2000rpm, and that this is the max amount of advance? And are you still happy with it? (Do you plan to experiment further?)

And the original unit before repair - I would guess with tired springs, advance comes in too quickly? - and with worn holes, too much? Have I understood correctly?

Yes, that’s the current set up. It too a while to get the right springs to acheive that. 
Experimentation is underway because I’m never fully happy that I’ve optimised everything.

The original unit had a baseplate that was sticking as well as ropey springs. Noting down the advance at steps through the rev range and subsequent hand fitting and was key.

[Chris KC]

Thanks Charles.

[Peter Naulls]

Andrew,  

In my case the over-advance was evident quite low in the rev range. It had good pick-up from rest, was very rough at low revs under load but quite happy at higher revs/maximum speed. Adjusting-out the roughness (by static timing) meant I lost the good pick-up and also compromised the top speed.

This left me fairly convinced that it would also benefit from a longer/later advance curve, i.e. lighter weights or stronger springs. There has been some discussion about this on Facebook in the past.