Yes, I agree,  both units come in fairly light, I think.  I used a

two

throat 4 injector TWM TB when I first started flying, but came to

the

conclusion that the two 2" dia holes just did not create enough

velocity of

the mixture to stuff the chambers fully at 5000-6000 rpm.

Apparently

worked

fine for the guys turning 8000 and above in race cars.  It is

certainly a

nice, well made unit and for your 3 rotor will probably be just

the

thing.

Onward to more (less weight that is) progress.

Ed Anderson

I chose the 44 mm diameter barrels, about 1 3/4".  Based on the drop

in

manifold pressure at high rpm, I was thinking larger would be

better.

But there are other factors, and until you can do a direct

comparison,

same engine, same engine; preferably on a dyno, you don't know.
Al

It takes about thirty milli microseconds to realize that ANY pressure

drop

across a throttle body at ANY RPM reduces the HP :) I am stunned. You

guys MUST

be kidding!!!

Paul Lamar

Ed, I have a question for you about your manifold.
Were you planning on using bondo inside your manifold to smooth the

walls out? The

reason why I ask is because the standing waves that we are concerned

about can

cause the fuel air mix to actually reverse and go up stream at times. I

was

wondering about the fuel being exposed to the bondo and disolving it and

coming off

inside the manifold. Do you think there would be any cause for concern?
Doug Mueller
RX-6 13BT
N900DM
Henderson,NV

Hi Doug,

    No need to use bondo as the "plenum" runners inside are cast using
silicone cores (of the size of the inside diameter of the runner tubes).
When I remove the silicone tube cores, the inside of of runner inside the
plenum is smooth as glass.  I stuck a piece of the cast resin from my first
failure in a cup of gasoline to determine the effect.  Went back and found
the cup disolved but the resin like new.  But, not a long term test and
certainly not under the more extreme conditions under the cowl.  Will stick
the test piece in more gasoline today in a glass jar and see what it does.

I designed the plenum such that the injector stream of gasoline impenges on
the metal wall of the aluminum runners, so hopefully will keep most of the
gasoline off the resin.
 Finished casting 1/2 of the mold last night and it turned out fine, but ran
out of silicone stuff, so could not complete the other half of the two part
mold.  Then I will be ready to pour the resin for the casting.

Appreciate your caution note on bondo.

Thanks

Ed Anderson

 
The AirCraft Rotary Engine NewsLetter.  Powered by Linux.
ACRE NL web site. http://home.earthlink.net/~rotaryeng/            
Copyright 1998-2003 All world wide rights reserved.