----- Original Message -----

From: Mark Steitle

To: Rotary motors in aircraft

Sent: Wednesday, July 21, 2004 2:43 PM

Subject: [FlyRotary] Re: Fuel Rail

Hi Al,
That brings up an interesting consideration.  Presently, I'm running 550cc injectors in the primaries, and 460cc injectors in the secondaries.  To get the primaries to idle smoothly, I had to reduce the map setting by 100 steps (from 0 to minus 100).  Max adjustment is +/-123 (there is another EM-2 Mode that allows you to change this, but Tracy warns to try to tune within the factory adjustments first).  FWIW, I can't imagine adjusting/tuning the EC-2 without the help of the EM-2 fuel map.  I now have my engine idling pretty well on the 550's, but need to wait for a prop to do any serious tuning.

What I'm really concerned about is if I have an injector failure and have to switch one bank of injectors off, what will happen to the mixture for the other bank of injectors?  Since they are two different flow rates, will this emergency procedure even work? 
I guess the simplest solution might be to install 550cc injectors in the secondary runners.  That would resolve the emergency concerns.  I'll try that and see how it runs. 

Thanks,
Mark



At 11:15 AM 7/21/2004 -0700, you wrote:

Mark;

 

You may want to see how well it runs before you go through a lot of work.  I have the 550 s in my 20B, and it ran reasonably well on the dyno at idle, although we didn t spend much time there.  The only problem I had was when I pulled the throttle from higher RPM and the MAP went below where I had corrected the mixture table, and it would get too rich and die.  I expect that problem will be solved with the EM-2 where I can adjust the mixture at low MAP without operating there.  My conclusion was that the Mazda injectors handle very short pulse widths prettywell.

 

I hope to know more in a few weeks when I have the thing up and running on the airplane.

 

Al

 

-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mark Steitle
Sent: Wednesday, July 21, 2004 7:59 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Fuel Rail

 

Bulent,
You lost me.  I did modify the original primary fuel rail by cutting off the ends and welding AN bungs in their place.  But that limits me to using the 550cc injectors.  I feel these are way too big for a n/a engine.  My objective here is to go to a 460cc injector.  But they don't come in the "low-profile" style (correct me if I'm wrong).  So, I checked and discovered that the the standard injector will fit under my custom intake using a stock 13B fuel rail.  I don't see how I could adapt the factory "low-profile" fuel rail to accept standard 460cc injectors.  I'll have to take a picture of what I'm talking about when I get home from work.  The "low-profile" injector that fits into the primary intake port sockets is fed through a screened opening on the side of the injector.  It has o-rings on the body to seal when inserted into the fuel rail.  I don't see how you could modify this to accept a standard injector.  Also, there are two mounting brackets just next to the injector sockets that holds the fuel rail and injectors in place.  I concluded that the easiest solution would be to use two standard 13B primary fuel rails, connecting them in the middle with a tube, than build one from scratch.  If push comes to shove I can build one from scratch.  A picture will make this much clearer.  Stay tuned. 

Mark


  At 11:00 AM 7/21/2004 -0400, you wrote:

On 7/21/04 10:10 AM, "Russell Duffy" <13brv3@bellsouth.net> wrote:

Anyone that has a 13B fuel rail they're willing to sell,

please contact me at msteitle@mail.utexas.edu.

Thanks,

Mark S.

Mark, my Cosmo 13B has the same injectors as 20B. I cut both ends of the original steel fuel rail and tapped them for 1/4 NPT thread. I m talking about the injectors mounted on the engine block. Can you do that with yours if you have it?
Bulent