Dennis,
Aren’t your primary and secondary tubes
different lengths from rotor face to rotor face? If so, what are
the two lengths? Are they different diameters?
Bill B
From: Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of Dennis Haverlah
Sent: Monday, February 15, 2010
9:56 PM
To: Rotary
motors in aircraft
Subject: [FlyRotary] Re: rpm vs
Power was : Throttle limits was Re: N.A. Renesis to turbo
Mike:
My intake tubes are 43 inches measured from rotor face of rotor # 1 to rotor
face of rotor #2. Design RPM was 6200.
Someone asked about my static RPM. Today I checked - with engine just
warm enough to open the throttle fully, I got 5870 RPM with my new
intake. With the engine completley warmed up I got 5700 RPM. This
demonstrates what Lynn Hanover has stated several times - more air/fuel enter
the combustion chamber at lower oil temps! I believe with my
original intake I only got about 5300 RPM static.
Mike Wills wrote:
So for that RPM, how long did your
intake runners end up being?
For what its worth, I tried to
emulate Tracy's
dynamically tuned intake as well. But cowl constraints probably compromised the
intake at the point where the TB is mounted. This is something I want to modify
anyway. As it is things are tight enough that I cant even run any sort of air
filter, so I do need to make some changes here - may as well try to do it
right.
I know I had a picture of your
intake - saw it just recently. But cant find it now. Could you re-post it?
Sent: Friday,
February 12, 2010 11:19 AM
Subject:
[FlyRotary] Re: rpm vs Power was : Throttle limits was Re: N.A. Renesis to
turbo
I used the same 65 mm Mustang throttle body on both my
original and new intakes. If I remember correctly, I believe I had
a longer unused throttle travel with the original intake but I never
measured it. I don't know the static rpm increase with the new intake -
probably have that in my notes some where but my max. rpm at high altitude
(8,000 - 10,000) increased 400-500 rpm. I estimated I went from 165 -170
HP with the old intake to about 185 HP with the new intake. This in in
line with Ed Anderson's recent note that Mazda got about a 16% power increase
at 6000 rpm with the DIE effect. I felt much improved acceleration the
first time I took off with the new intake.
The new intake is based on dynamic intake
effect (DIE) where the closing of an intake valve caused the
moving intake air to bounce off the valve creating a pressure wave. The
wave travels at the speed of sound to the other intake valve and arrives there
just before that valve closes. This increases the amount of air and fuel
that enters the combustion chamber. (As we know the rotary has no valves
but uses the sides of the rotor for opening and closing the intakes.) I
designed my intake to give max. performance at 6300 rpm.
If I had cut down my prop to 74" it would give me more clearance for the
prop on my RV-7A and increase my top end rpm. Max rpm is about 6400
rpm with the new intake and the 76" prop. I'm really not needing
higher RPM now.
Dennis Haverlah