I am no help at all on the electronic stuff. I have to use it. But I will never like it.

 

1) One rotor face below compression spec is in fact (probably) an under performing side seal.

 

    A corner seal or apex seal will lower two rotor faces. In your case I doubt that there is any affect from this as the leak time at the problem RPM is way too short. More likely to show up at very low cylinder filling situations as at idle. Lumpy idle or similar. So, not a factor.

 

Compression checks are done on engines at operating temperature. Failing side or corner seals show up first as increased blow-by. Loss of high speed power may be minimal. undetectable.  

 

Your EGTs suggest good to slightly rich mixture. Take off and climb power with a bit of fuel cooling.

 

Such temps can be provided in other ways. Such as too rich and too much ignition advance.

 

Or, way too lean and late ignition timing. A nice heated Oxygen sensor would be helpful.

 

A rotary will run way over rich (Black smoke) and way over lean. Still sound good but has no power at all.

 

Lean cut off may feel more like an ignition switch being killed rather than a stumble. It will sound good on either ignition with one failed, but have less power on trailing only, unless firing both at once. Worse if trailing is retarded some amount.

 

On lost spark systems you can short out the trailing plugs one at a time to see if a plug is shorting. Same for leading. On CD systems use plastic hemostats, or have your name sewn into your clothes.  

 

So, what is the ignition timing? 20 degrees is fine up to 9,500 RPM. Also good for poor octane and alcohol

tainted fuel. Old 80/86 or similar.

 

 We raced on the (poorest lowest octane) non alcohol fuel available. Look at BTUs per pond not octane. For higher octane street fuel or avgas, 24 to 26 degrees is fine. This data is for unboosted engines only.

 

 Boosted engines require reverse timing, where advance is pulled out with cylinder pressure increases.  

 

Firing both leading and trailing together? Never light trailing before leading. 

 

If the coils fire two plugs each, I would reduce gaps to .010"   Because the gaps on a lost spark system add in series.

 

The rotor moves about at one third the speed of the crank. The timing marks are on the crankpulley (or better yet on the flywheel). The combustion event is on the rotor face. So 30 degrees here is similar to 10 degrees in a piston engine. Also the dwell period is long. Smokey would love this engine. Not much advance is needed. Some racers use up to 35 degrees with very high octane but they generally rebuild after 8 hours.

 

Since the airplane is a dyno, you can test on a safe 20 degrees or 24 degrees and later just make runs at higher advance and establish your best power set up.  

 

If the engine runs through the problem RPM at low pitch but the problem appears at higher pitch (higher load) there may be an unhappy tune, in the intake length and or diameter, or plenum volume.

 

Also higher pitch(more airflow) may show up a pressure change in the intake air cleaner or plenum.

 

Higher pitch and larger throttle opening produce higher cylinder pressures that can show up secondary ignition faults. Just some ideas. Maybe one will help.

 

Lynn E. Hanover