The point about cranking speed, is that the rotary with so many gaps in the sealing system around the rotor face that it leaks compression like a screen door. I use the early top mounted starter on my race car because you can drive the car to the grocery and back on the starter motor. If it was a piston engine it could spin it up to the red line. It is too heavy for the airplane but the point is, at one time every Mazda had a giant starter motor on it. Thus eliminating the hot start problem. Liquid fuel just shorts out the spark plugs. So a fast turning rotor can generate enough compression heat to vaporize a rich or liquid mixture and have a chance at lighting it. (The time component of the leak rate is shortened by the higher starter speed)

 

On the old cars in addition to the big starter, there was a bottle on the fire wall that was to be kept full of anti-freeze. In the winter, frost would form on the housing chrome and rotor. When cranking would start, the frost would bush the seals deep into their grooves and the complete lack of compression heat would get you a no start. So the starting circuit included a pump to drip anti-freeze into the carb during the start to wipe away the frost.

 

When electronic ignitions came in, and the 2 piece apex seal became standard, the anti-freeze bottle vanished. The modern high speed geared starters spin fast enough but need a big current supply. Check with Tracy to see if his system can trigger a High energy ignition system, and try one on the leading plugs at the least.

 

I have a MSD 6AL on both leading and trailing and the plugs gapped at .010". I build the engine with zero clearance on the side seals. So long as the side seal and the corner seal will pop back up when depressed, that is loose enough. I can use an engine two years when built that way.

 

Starts hot or cold. Lean or flooded. (Important with some drivers) In one stab of the button. Like day and night over a stock system. Keep your hands away from these things, or, wake up trying to remember your name. Starting a flooded engine will often get you a fire ball from the exhaust of monumental size.

 

Lynn E. Hanover 

 

 

 

I've not been to the hangar in a while.. I dont think Chris has
indicated any CRANKING problem, rather a STARTING problem when hot.