Hi Jim,

Being one of the early Rotary Fliers and knowing no one (at the time) with a flying rotary  and there being no such e mail list as this to ask questions, I decided on extensive ground testing.  I build a test stand that duplicated my planned FWF installation.  Mounted the engine and ran it in the test stand for over 30 hours ground  run time.   Keeping in mind that so far as I knew at the time – the rotary had not been yet proven in aircraft application.  In fact, the few folks that had tried it never really achieve success even though a couple did get into the air.

But, in any case, here is what I believe the ground test program provided me (some of the factors have now been demonstrated by many others and can be accepted with such ground running.

1. Reliability and robustness of the engine (yes, I manage to over-heat it a couple of times – once to the point of having to replace the stock coolant “O” rings)
2. Worked out some changes in component installation on the Firewall
3. Proved that the GM evaporator cores (used as radiators) would indeed work
4. Showed that the EFI pumps would indeed “suck” fuel up-hill at least 2 feet and once even caused a heavy duty marine type fuel container to collapse due to the pressure differential (for got to undo the vent cap).  Note: having a EFI “such” fuel rather than “Push” fuel is not recommended.  The pumps should be “wet” at all times when operating – even 30-50 seconds without fuel can damage their impeller.
5. Showed that my semi  “returnless” fuel system (1/2 pint header tank mounted on the firewall) worked
6. Showed that my “Plugs Up” orientation of the engine was indeed viable.
7. Convinced my self that the engine would put out sufficient power to make it a viable power plan (although not nearly the power I got out of it later after completely redesigning the induction system)
8. Gain considerably knowledge (still learning) about  and confidence in the engine ( 500+ hours run time) and 10 years since first flight.

Now, having said all of that, much of the above can be taken as proven and no need to further reinvent the wheel.  If however, you are talking some new approach to some element of a critical system such fuel, ignition, cooling or lubrication, then you might want to verify that your concept is viable on the ground rather than in the air.  On the other hand, if you are pretty much following practices that have been proven by members of this list then there is probably no need for a ground test program other than what you do to prove your installed setup  works as planned.

The further you depart from what has been shown to work, then the greater the need for a ground test phase, in my opinion.  Being in the air and finding out your idea is less than ideal is not the place to be.

Just my 0.02 worth

Hope this helps.