I've got one fitted to my Series "A" Comet. It used to dump the whole tank into the sump in a week. The Conways valve stopped it and has never been a problem. The pump on an A is a gear type pump and as a pump is very good and is capable of providing a good lift of oil from the tank at a high pressure. The return into the tank is a constant squirt rather than a drip-bubble-drip-bubble that you see on a post war pump.
I would have no problems recommending the Conways valve for a Series A, but would think twice before fitting it to a post war bike as the lift of the pump is a lot less and my worry is the pump would not open the valve.
My brother-in-law's "B" Rapide would sump over 2 weeks. What he did was to drill the sump drain plug 1/4 BSF and seal it with a short bolt and copper washer. To drain the sump he removes the 1/4 BSF bolt and leaves the original drain plug in. That way you won't damage or wear the threads in the crankcase.
Simon
I would have no problems recommending the Conways valve for a Series A, but would think twice before fitting it to a post war bike as the lift of the pump is a lot less and my worry is the pump would not open the valve.
My brother-in-law's "B" Rapide would sump over 2 weeks. What he did was to drill the sump drain plug 1/4 BSF and seal it with a short bolt and copper washer. To drain the sump he removes the 1/4 BSF bolt and leaves the original drain plug in. That way you won't damage or wear the threads in the crankcase.
Simon
