(Big Snip)---

Robin mentioned to me today she thought before somebody could get
their airplane flying with a rotary they must become an engineer
if not a full blown  scientist.

Paul Lamar

Ken Powell wrote:

Paul,
Those of us who are not engineers must learn to be pragmatists and to be 'logical thinkers'.
I think that there are many on the newsletter who have these traits who are not engineers.
However, (the other shoe falls), without the help of the engineers we are almost certainly doomed
to overbuild every component and to have a heavy airplane.  The airplane may or may not be safe.
We need you guys to help us understand the science.  I value the help of the 'rocket scientists'
on the list.  My airplane will be better and safer because of you guys.

Thanks of the help,

Ken Powell
kenpowell@aristotle.net

You are welcome Ken. 

BTW Each installation seems to be different. Until we have 100's
of RV4 flying with the same rotary engine or any other AC type each 
installation will continue to be different.

This is not the case with RV4's with O-360 Lycomings. There are hundreds 
and they all can be the same. Same goes for Cessna 182's. They
are highly developed and optimized.

My AC racing friends pooh pooh the rotary because the airplanes rotaries
are installed in seem to be slower than the same airplanes with Lycomings 
with the same claimed installed HP. So far nobody has raced a rotary
to prove them wrong. Our credibility is currently lacking.

We also tend to think our experimental airplanes are all the same. The 
dynamic chamber or intake manifold that works best on one RV4 with a 
particular over all drag will  not be the same as the dynamic 
chamber or intake manifold on RV4's with other drags or year engines. 

Cooling drag is the big drag variable. At the rate we are going it is
going to take years to optimize cooling drag and standardize. The water 
manometer is the key tool to make this happen sooner. I digress slightly.

It would also help if we could tune the intake just like we tune the prop 
pitch and diameter. A variable pitch prop will go a long way to mitigating 
this problem. Turbo engines are easier in a way as you can just up the
boost. I suppose the contest then will be the top speed to boost ratio :-)

Paul Lamar
 
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