mine has the fixed ridge ignition. I have never run it. when i force gas into the carb it will pop so i know the ignition is working but the internal parts of the carb stay dry and it will not draw gas at all. I have owned Sachs and Brison engines way back when and i liked them. the heavier weight is good in warbirds.
The WWI Fokker DR-1 has the firewall set up for the FPE / Brison type motors. It is all done and painted. Balances perfectly so that is why I was trying to stick with the same type of engine. I have a DA-35 but i would have to add lead weight and cut a hole in the firewall / modify which I don't mind doing during the build but was trying to avoid on the completed airframe