3. Some think the Rotary is a do-all. Even with the 2.85:1 reduction
drive like I have.  We need to listen to you and Tracy for best results.
 A heavy Lance Air with a 20B and 2.85 drive may not perform like the

man wants.

Jerry Bass

Mark Steitle wrote:

I guess this refers to me.  So, here's my rationale.  I am building the
Lancair ES with the n/a 20B and 2.85 redrive.  Yes, it is a great engine, a
"do-all" its not.  (But I do believe its way ahead of a
Lycosaurus)   However, I do anticipate performance equal to, or better than
the 210 hp IO 360-ES powered Lancair ES.  I don't think there is any doubt
that a n/a 20B will produce in excess of 210 hp.  At that hp figure,
Lancair claims a cruise speed of 192-200 mph.  If I get that, I'll be happy.

The Lancair Super ES (my airframe) is designed for the IO 550-G, rated at
300 hp at 2700 rpm.  With this engine, Lancair claims a slightly higher
cruise of 220-225mph, not that much higher than with the IO 360.  I don't
know if I can get there with a n/a 20B, but that's not the point.  I'm sure
I'll get somewhere between 210 and 300.  My initial goal was build a
4-place plane that would cruse at or near 200 mph.  I think this is still
realistic, using the 20B with a 2.85 psru.  If I wish to in the future, I
have plenty of room for a turbo.  Zoom, zoom.

Mark S.

Not me. I think it is going to work great. Even at a 80 HP per rotor
level you will have 240 HP. That should be a piece of cake.

Perhaps Jerry's intake manifold is not working as well as it could
giving him that impression. That reminds me Jerry, do you have a manifold
pressure gage? I suspect you are getting some pressure drop across your throttle
body.

BTW Jerry, I know you told me the specs on your RV6A but could you reiterate
them for us?

Top speed?
RPM at top speed?
Manifold pressure at top speed?

Cruise speed?
RPM at cruise speed?
Manifold pressure at cruise speed?
Fuel burn at cruise speed?
EGT at cruise speed?
Fuel mixture at cruise speed? (If you have a working O2 sensor.)
Prop pitch and diameter?

Paul Lamar

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