Looking for the rotory equiv of Lycoming IO-360 A1A.

Thinking #B something from the chart on the web site. Can you advise?

also would like recommendations for compatible constant speed prop.

John Hardin

Read:
http://www.rotaryeng.net/intake.html
http://www.rotaryeng.net/fund-of-intake.html
http://www.rotaryeng.net/Welded-steel-p-port.html
http://www.rotaryeng.net/HOW-TO-INSTALL-HOLLEY.html
http://www.rotaryeng.net/Mazda-p-port-press-wave-enhanced.jpg
http://www.rotaryeng.net/slide-throttle.html

At this point the only thing that seems to work is the MT or Hoffman
electrical props.

No constant speed gear box available.

Paul Lamar

You have forgotten the vari-prop. http://variprop.com/
Works on standard gearbox.

C. Smith

Some Cozy people say that they are having good luck with IVO
Rich

Not really a variable pitch. Variable twist.

High power to weight ratio experimentals don't really need constant
speed props.

There is a problem is getting the right pitch and twist for
either cruise speed or top speed. Your choice. Ground adjustable
do just fine if they are twisted properly.

Constant speed props are great for getting a heavy airplane off the
ground and climbing out. Also good for sea planes where you need
a lot of low speed thrust to get on the step.

STOL is another matter but they tend to be rather slow anyway.
Now if you had fowler flaps and movable leading edge slats well
then yes. By all means C.S.!

Paul Lamar


Well, I guess I'm not as versed in the precise technical terminology. I thought that twist was the change of cord angle relative to root along the length of the blade. Pitch is the difference in the angle of the blade relative to the "airflow". A C-182 with a CS seems to be a fine combination.
I don't understand the disadvantage of the CS.
In addition to T.O. and climb performance advantages for heavy and seaplanes is there not also an advantage in being able to load the engine with the CS and increase fuel burn efficiency in cruise? Is that not the best of both worlds?
C. Smith

Yes twist is the change of cord angle relative to root along the length of the blade. But that is exactly what the IVO does. It is the only thing the IVO does.

Other than cost and weight there are no downsides to CS.

Yes there is an advantage in being able to load the engine with the CS and increase fuel burn efficiency in cruise. However if you don't need the TO and climb performance why pay for the extra cost and weight. Most runways we fly off are at least 2000 feet in length with few obstructions. I have flown with Tracy Saylor in his RV6 O-360 with CS and it breaks ground in about 300 feet.

The C182 prop weighs 50 pounds not counting the $1000.00 dollar governor.

You can set the cruise prop pitch angle for the best engine load and let everything else be what it is. People do it all the time. The VAST majority of experimental builders  attempt to do just that with fixed pitch props. The problem is one must sell the fixed pitch prop one has or send it back to the builder if you get it wrong the first time as most people do. IMHO a ground adjustable is more appropriate with little or no weight penalty.

Here are some installed pictures of the Variprop on Perry Micks Long EZ.
The pump assemble is quite heavy.

Paul Lamar

Hmmm. How old is Perry's installation? I was told by Larry Morgan of Vari-prop, that total weight of the system was 36 lbs. Perhaps they have improved it, or he left out the pump.
C. Smith

I took the pictures in 2009.
Since the blades are wood that could be the total weight.

BTW the new Senenich carbon blades are hollow so advantage to them.
Wood bladed props are generally less efficient than metal blades
with thin tips and sometime carbon blades if an effort is made to keep the
carbon tip cord thin. Much of the absorbed HP goes in to overcoming transonic drag near the tips.

Paul Lamar

Old message:
--------------------------------------------------------
> >    7-22-2009
> >
> >    My Rotary Long-EZ has been flying for 10
> > years
> >
> >    720 hours TT
> >
> >    Zero glider time
> >
> >    http://www.mickaircraft.com/duckt.htm
> >
> >
> > How is your Vari-Prop working out?
> > Thanks,
> > Ernesto


I flew it on two test flights about a year ago. The take-off performance was intense. Not even full throttle and I was off the ground in no time - quite different than what I'm used to. However it weighs over 50 lbs. and I had to add a 14 lb. lead brick in the nose. They are building a lighter hub for me as the original is designed to survive four-bangers. Very slow progress.

Perry Mick