P2 Dynamic timing advance issue?


New Member
Can anybody help please? I am trying to set up my '47 Rover 12. I have fitted a new Solex Carb and refurbished the mechanical fuel pump. I have tightened all the linkage in the distributor to remove any free play and have set the static timing to 11 deg BTC. It starts remarkably well and idles well. Low speed power seems quite good and will get to 40 mph sufficiently quickly - on the level. However, on hills it runs out of power and the speed drops dramatically to. It feels like the ignition needs retarding. I rechecked the timing dynamically and with the engine idling (around 650 rpm) the timing is showing around 26 deg BTC. Reving the engine advances it more. This seems excessive, as if the distributor has the wrong advance springs. Does anybody know how to check if the springs are correct, or what the correct springs (spring rates) are? Also it has two different springs fitted, presumably to give a 2-stage advance curve, but this seems a little advanced for a car that age. Can anybody help with advice please as to how check the CF advance is behaving correctly?
At idle the advance should be at or close to the static number. Either your static measurement is incorrect or the weight springs are weak or broken. Given it still goes up when you rev it I'd say the first is the reason. Reset the distributor to 11 degrees when idling. You might need to adjust the idle mixture when doing that.
The points plate that moves for centrifugal advance can get stuck on the inner shaft. Its usually retained by a plain screw (maybe under some oiled felt) - remove and make sure its free to turn - if you lift it it can come free of the weights, so take care.