Paul,

I am a mechanical engineer that owns a cnc machine shop in northern
California. As a new pilot, and a past rotary engine builder, I am in
the progress of developing an aircraft specific rotary using some off
the shelf Mazda parts and many custom parts. The current goal is to
offer these parts to the experimental aircraft market within the next 2
years. I am estimating around 1 year of design and prototyping and a
year of endurance testing before release of any products.

The real motivation is I will be starting a Velocity XL kit this fall
(after the Reno Air Races), when my time will become a little easier. I
am the team engineer and fabricator for Team Steadfast owned by Will
Whiteside. We use a 2005 Romanian built Yak 3U with a P/W R2000 radial
engine. You can check out the web site at teamsteadfast.com.

Please add me to your newsletter mailing list. Your web site is great!

I would like to use you as a sounding board to possibly review some of
the parts we will me making on the basis you keep them confidential
until we are ready to release the parts to the market. My plan would be
to resale the parts through the existing guys building rotary aircraft
engines, as I really don't have any interest in being an engine
assembler (besides my own)!



Thanks,

Larry Childs



Designit Prototype

5935 Labath Ave

Rohnert Park, CA 94928


Cell 707-753-0702

I'll be glad to help anyway I can.

You are also just the person I have been looking for.
I have been farming prototype work out to various local NC machine shops
but I would rather keep it in the Wankel rotary community. I pay for it
out of my own pocket no problem.

I am trying to design a slide throttle low pressure fuel injection
based on the Ellison carb. We have a guy already set up to make
the slide throttle itself. I am building up a p-port RX8 engine
and we will initially run it on the Mazdatrix engine dyno with a Weber carb
to get a base line. Once that happens. I will try some of these other ideas for
low pressure mechanical fuel injection. The traditional EFI is overkill and too
expensive. Most people are attracted to the rotary for cost reasons.
Also it relies on a functioning electrical system which does not always function.


    This design steals ideas from Ellison and Mikuni.
    The fuel metering is done with a bunch of small holes
    drilled into a brass tube that stays in the air passage
    all the time similar to the Ellison. As the slide opens it exposes more
    and more small holes in the brass tube increasing the fuel flow.
    The brass tube is attached to the spacer. The fuel comes in through the
    spacer and down the column to the brass tube. The brass tube
    fits in holes in the center parts of the slide. The fuel is
    sucked out of the side of the tube by the Coanda effect.
    Ellison claims excellent atomization.

    It uses a tried and true method of metering fuel. There are
    hundreds of  Ellisons out there on all sorts of airplanes.  The mixture is
    also leaned with the external fuel pressure regulator. The Ellison of
    course has a built in fixed fuel pressure regulator.

    I calculated the air opening area of the slide in .2 inch travel
    increments. I then attempted to match the fuel flow to the slide opening area.
    Roughly speaking it takes 27 .013" dia. holes variably spaced
    along the tube. Each hole passes enough fuel for 4.45 HP at 2 psi so
    27 holes is 120 HP per runner. 240 HP for the p-port engine.

    As Ben Ellison says this causes a stepped ramp digital supply of fuel.
    In other words the engine goes from rich to lean and back to rich as
    the  slide moves. The problem is severe in the first one third
    travel of the slide throttle. Ellison largely got around this by
    using much smaller holes and many more of them. My guess by looking at them is
    they can be as small as .1 mm or around 6 thousands of an inch. He probably has
    close to 100 holes in his tubes.

    More, much smaller holes, soon becomes a problem in a single row as
    the holes  get too close together. Two or more staggered rows are used in the
    Ellison. The first 3rd are a single row. The next third  is a staggered
    double row and the last third is a staggered triple row. None of this is shown
    on any  Ellison websites. Of course this further increases the cost.

    I talked to a friend of mine that owns an NC shop here in Santa
    Paula that  has experience drilling small holes. He says there must be a close
    fitting  brass rod in the  brass tube or drill breakage occurs frequently. At
    $45 a crack  you don't want this to happen. Then you have the problem of pressing
    the  sacrificial brass rod out of the nine inch long 1/8 inch diameter
    tube.

    Not an easy thing to do. That too requires special tooling that supports
    the outside of the tube. Perhaps this can be done better with a laser.

    I  have  yet to investigate the laser option.  I am sure this outfit can do
    the job. I'll know more about the cost on Monday.
    http://www.calasers.com/gallery.html

    Two Ellisons would work fine but at $850 each they are too expensive
    for most rotary guys.

Paul Lamar ...No rotor no motor.

  The Holly regulator is a piece of junk, use a Barry Grant regulator.
 Ken

Thanks for the tip Ken.

Paul Lamar ...No rotor no motor.

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