21-10-2018, 09:46 AM
Further to Peter Burtons comments on page 6 I tried auto distributor on my RP years ago, for some reason without manual override, but soon reverted to manual as was never sure if it optimum retard whilst maintaining power. It is difficult to separate performance from noise. In a very hilly city and in stop go traffic the manual often enabled a brief difficult change into 1st to be avoided by retarding the spark. Of course, as with most, the springs fitted and exact advance characteristics were anyones guess.
I occasionally get enquiries about optimum advance for Javelin cars and Bradfords. For the keen I suggest arranging a temporary manual override. The throttle controls from lawnmowers, some choke controls etc can be quite simply arranged.
I am always mystified by the claims of smoother operation with new substitute distributors. There is spark scatter with an old worn unit, but a good one is essentially same as millions of other Brit cars. Apart from making the engine sound rough I dunno if scatter makes much difference to power.
The spark occupies very many crank degrees; possibly with a modest system ignition is not always immediate, even with a normal strength mixture. Like pregnancy there is either ignition or not. But cars with poor plugs, insulation etc often run at low power without actually missing. I suspect ignition occurs late in the spark period. I found on my car closing the plug gaps made the engine more smooth, like retarding spark, so the form of the spark makes a difference.
I occasionally get enquiries about optimum advance for Javelin cars and Bradfords. For the keen I suggest arranging a temporary manual override. The throttle controls from lawnmowers, some choke controls etc can be quite simply arranged.
I am always mystified by the claims of smoother operation with new substitute distributors. There is spark scatter with an old worn unit, but a good one is essentially same as millions of other Brit cars. Apart from making the engine sound rough I dunno if scatter makes much difference to power.
The spark occupies very many crank degrees; possibly with a modest system ignition is not always immediate, even with a normal strength mixture. Like pregnancy there is either ignition or not. But cars with poor plugs, insulation etc often run at low power without actually missing. I suspect ignition occurs late in the spark period. I found on my car closing the plug gaps made the engine more smooth, like retarding spark, so the form of the spark makes a difference.