Hello all,


I'm putting a Renesis engine in my BD-4 and I'm running into a
clearance problem with the tops of the oil injectors and the
intake. I'd like to make them shorter by removing the fitting
on top. I want to know what's inside the injector and do I need
to have it connected to a vacuum source? You can blow through
the top fitting and air comes out of the nozzle end, but you
can't suck air back through. Any information would be greatly
appreciated.

Kevin
Nova Scotia

 What motor mount are you using? Sounds like your thrust line is
too high. Here are are some pictures of another rotary powered BD4 with the
coils mounted on top of the engine.

The oil injectors are subtle devices. There is a one way valve in there
that allows intake vacuum to draw in the oil. The hose leading out the
top goes to a source of atmospheric pressure. Not to a vacuum source.

In the early RX8 engines with only two oil injectors per rotor
not enough oil was injected and apex seals failed prematurely. I
mix a half ounce of 2 cycle oil to a gallon of fuel in my 2004
street RX8 car. Around 2007 Mazda added a third injector per
rotor to solve the problem.

However most aircraft people take the whole oil metering system
off an mix 2 cycle oil with the fuel. That does a much better
job of lubing the apex seals and burns cleanly leaving no
residue coating the rotors. All you need is one ounce per gallon
of fuel.

Paul Lamar


Kevin, I'd love to compare notes on your BD-4 project.  I'm planning to put
a rotary in my BD-4, although I don't expect to be at that stage until
sometime next year.  Any tricks and traps you care to share would be
appreciated.

Regards,

Tony King
Brisbane Australia

Kevin--
    Ditto Tony King's comments for my situation, too.   Thanks!

Paul Vermillion
Fort Walton Beach, Florida


Hello again,

Thanks for the information paul, I did some more measuring, and
found I should be okay with clearances after all. I'm using a
Jerry Hey mount, and a Richard Sohn oil meter adapter. I'll be
mounting a reservoir with two stroke oil just off the fire wall.
For the other Bede fellows I'll attach a link to my builders
profile. A problem I ran into with my engine mount was the
clearance of the tubes as they connect to the airframe. The
angle is too steep, and I had to grind a little bit of the frame
away. Jerry recommended I put the engine further forward and I
should have listened to him. I tried to keep it further back
because the rotary is a bit heavy, and when I add a turbo it
will get even heavier.

http://bd-4.org/builderlist_sheet.php?id=180&session=scDMFs72&user=Kevin

Kevin
Nova Scotia

You are still going to need 2 cycle oil in the fuel because the
two oil injectors are not enough for the early RX8 engine in aircraft use.
The center of the apex seal still runs too hot and will wear out unless it is
cooled with an adequate amount of oil. The oil is not getting to the center
of the apex seal where it is needed most. Mazda does not often make mistakes
like this but they were under pressure to reduce the apex seal oil
for smog reasons.

I assume you are going to rig the RX8 stepper motor controlled apex oil
metering pump to put out max oil some how. How do you plan on doing that?

You can probably get some weight out of Tracy's gear box if you
know somebody with a lathe :)

Paul Lamar