David,

I consider all these excellent comments and I like your reasoning. It w= ould=20 be nice to see what you could get with even a better fixed pitch prop match.= =20 Something about fuel burn. I have mentioned this repeatedly in several of th= e=20 forums on Vansairforce.net too, and that is the higher the output the better= the=20 rotary looks efficiency wise. Mistral's new numbers using their high-end EMS= are=20 competitive, in fact just plain good when using lean of peak operation. This= is=20 all part of using an engine that is an infant compared to the piston engine.= We=20 are still learning a lot. Thanks for your participation, from all of us that= =20 aren't ready yet.

Bill Jepson

In a message dated 4/7/2008 5:02:05 PM Pacific Standard Time,=20 wdleonard@gmail.com writes:

<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>There is=20 not doubt that I would have been at least several knots faster with a C/S=20 prop. I could even pick up a couple knots average time with a little= =20 less pitch in my current prop. A two-bladed prop would have improved= =20 efficiency somewhat as well. But that would have been well offset by= =20 increased fuel burn.

I have gotten several comments from the guys i= n=20 the local group commenting on how surprised they were were at how well the= =20 rotary did in terms of fuel burn. I have to admit that I was rather=20 surprised as well. I think that the major objection to the rotary is= =20 often the excess fuel consumption and not the thought that it can't make=20 enough power. So in that sense, I think I did more for the reputatio= n by=20 being modest in both consumption and speed rather than going really fast a= nd=20 burning a lot of fuel.

Most people also realize that I was also=20 disadvantaged by the fixed pitch and 3-bladed prop and are impressed that=20= I=20 still essentially tied for second among the side-by-side aircraft.

= The=20 other important reason for keeping a fixed pitch prop is clearly the=20 cost. Not just from my pocket book, but to make a statement as=20 well. If we are using alternative engines to save on the exorbitant=20 costs of certified engines, then it does not make much sense to spend=20 thousands on the prop.

My engine/prop package cost at least $15k le= ss=20 than anyone else in the race and by using MOGAS my fuel costs were less th= an=20 anyone who was going for speed. That is what is cool!

Though,= I=20 must admit, it would always be nice to be the "Fastest Mother F'er" =20 :-)
--
David Leonard

Turbo Rotary RV-6 N4VY
http://N4VY.RotaryRoster.nethttp://RotaryRoster.net