Difficult to do with a Magneto unless you can feed an externally sourced spark into the distributor end. Easy to do if you have a automotive distributor. The Corvair typically uses a MSD 8210 coil combiner to run two spark sources to a single plug. Very reliable and flight proven but as with anything there are weak links. Particular attention to detail wire selection and ring lug termination is paramount.How do people do redundant spark using two feeds to one spark plug?
I am thinking of using computer spark alongside magneto fixed advance as a dual system into one plug.
Most auto conversion failures are ignition related.
Losing one cylinder in a four-banger is almost like losing two cylinders. That dead cylinder, instead of contributing, is robbing power from the rest as it takes in air, compresses it and exhausts it. We had a 150 eat a valve; one cylinder dead and the airplane could not maintain altitude. And that was with no compression happening, since the valve head was gone.Seeiously when is the last time a coil on plug or coil near plug system failed? And when it did the whole engine didnt quit, you just loose one cylinder.
Have you driven a ford lately? Early 2000 F150 were famous for shooting plugs right out the head (bad engineering, not enough threads for the plug to hold). They also had COPs which were prone to breaking.Seeiously when is the last time a coil on plug or coil near plug system failed?