No, Mike, your reply to my statement is ludicrous. There is a huge difference between lightweight 2-stroke aircraft engines and 6 to 14 cylinder marine diesel engines.
You can supercharge any kind of engine....that is if you can figure out HOW to do it. 2-stroke Bombardier-Rotax engines do not lend themselves to supercharging. Nobody builds superchargers or turbochargers for 2-stroke Bombardiers. Most of the Rotax engines you see on ultralight aircraft were originally built for SNOWMOBILES. Rotax DOES manufacture a 4-cylinder, 4-stroke aircraft engine intended for general aviation. It is possible to build a turbo charger for it, but to the best of my knowledge no one has.
High revving 2-strokes are extremely sensitive to fluctuations in operating temperature. As I said before, Bombardier-Rotax tells you to never attempt a takeoff with a cylinderhead temperature of less than 375 degrees F. Most of these engines are equipped with an iron-constantine thermocouple connected beneath the spark plug on the rear (hottest) cylinder. When heat is applied to the thermocouple, it generates a micro DC voltage which drives a voltmeter recalibrated into degrees of heat. In other words, the CHT gage is in actuality a volt meter. The hotter the bi-metal thermocouple gets, the more DC voltage it generates. The gage merely converts volts into degrees of heat on an analog scale.....sometimes digital.
If the CH temperature should reach 500 degrees F., you can almost count on melting a piston. The engine will not run on only 1 cylinder (if it has 2) because crankcase fuel/air pressure is lost and the 'running cylinder' will quickly fail because of starvation. Ask me how I know!
At 65,000 feet, the Strat will not use 36" diameter props. They are completely inefficient at that altitude. Instead, it will need large flat paddles, like the old Lockheed Orion turboprop aircraft.
That presents another problem. 2-stroke engines like to operate at high RPM. They even idle fast. To prevent the props from overrevving, a speed reducer must be employed. With most conventional ultralights, a 2.1 to 1 reducer is used. Why the odd number? Because they don't want the engine power stroke and the position of the propeller blade to occur at the exact same place every revolution of the prop. A 2 to 1 reducer will set up a tremendous vibration that can literally dismantle the airplane in the air. Besides that, if you try to turn a 60" swing prop at 6,000 rpm, it will disintegrate. 2.1 to 1 gives you a maximum prop rpm of around 2900 rpm.
If TAO is going to supercharge a 2-stroke engine and attempt to fly it at 65,000 feet, they will need (1) large flat four bladed props (2) geared to approximately 6 to 1 (to prevent overspeed) and (3) a 3 or more stage turbocharger.
The other option would be a closed loop system whereby the engine exhaust and intake system is completely enclosed and pure oxygen and fuel are added to the exhaust - the way they did it with Pegasus. Unfortunately, the spark plugs on Pegasus carboned up and the bird crashed on takeoff.
TAO has their collective engineering hands full with that project.
