Lynn, 
 
You've told us that the rotary like about 25 degrees BTDC of advance, and will run well at most any speed at that setting. Does that include starting speed? How much will performance be degraded as you back off to 10 degrees BTDC? 


For starting, I don,t know if you could tell. But off idle it would be un responsive, and have high EGTs. It has a very short stroke and very low torque. If you are worried about over advanced ignition causing a problem, just do 20 degrees. Once it gets broken in after 5 hours of hard running, it will start instantly at any setting between 20 and 27 degrees. 
The leading plug must always fire first. Or, both at once. Leading needs the coolest heat rangeplug. On the dyno the 13B will take up to 32 degrees but it isn't making more power, just more water temp. Too much advance puts the rotor face in front of the leading plug and makes the plug tip run real hot. A bad idea. Years ago you could see cracks radiating from the plug hole. From over advance and people screwing in a hot street plug from a piston engine.

When compared to a piston engine, there is no advance at all. The timing is taken off of the crank pulley wich is turning three times faster than the rotor. There is plenty of time to burn the fuel even at speed. 30 degrees at the crank is only 10 degrees at the rotor. Smokey would have loved that dwell at TDC.

Lynn E. Hanover 
 
 
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