Stromberg ignition advance

[69S4]

Some (many) years ago I had to replace the original distributor when it developed a crack in the casting. The replacement was the later 43D4 version - what Matty's had in stock at the time. The car has run reasonably well with it ever since but the timing strobe shows a maximum advance of around 24/25 degrees. Take away the static setting of 9 or 10 means about 14 degrees of distributor advance. Examining the advance weights recently I saw a 7 stamped into one of them so I'm guessing that represents 7 distributor degrees or 14 crank ones = what I'm seeing with the strobe.

I've had a look through the archives and there is a lot of stuff on advance curves, but mostly applicable to the Weber versions. I also have the Wilkins twin cam book and he gives advance curves for the Stromberg engines but the applicable 40953 curve does seem to be at odds with the others, bringing in a lot of advance very quickly.

The http://www.distributordoctor.com/ is happy to sell me weights and springs but I'd need to know what to get, so I'm seeking advice on what the advance characteristics should be. The engine is a UK spec Stromberg SE.

[m750rider]

I'm not sure if US and UK versions are the same timing, but in my US version 69 S4 with Strombergs I run about 34* at full advance. It will be full advance probably by 2500 rpm.