Al, Tracy does not insist that you use the DPDT switches - in the manual they are listed as optional.

I looked at the circuit and concluded that in order to have circuit breakers plus DPDT switches, my parts count was going to double; with panel space at a premium, I bought SPDT switches with built-in circuit breakers.

Also, I thought the chance of an injector failing in flight was pretty remote – as mentioned in the manual.

 

I do test both sets of injectors before flight, but have been doing it above the staging point – PRI:OFF-CS:ON; CS:OFF-PRI:ON … repeat with SEC. This gives you on-the-ground experience of what a bad set of injectors does to your engine plus the effect of what the CS is doing.

I do agree that the DPDT switches would be less awkward but I will leave things as-is for now.

Jeff

 

 

Subject: [FlyRotary] Re: Below staging ... was Re: More progress, more questions....

 

I do not have the DPDT switches but rather have separate PRI and SEC power switches plus the Cold Start switch. To test the above feature (which I have not) I would have to first ensure that the Cold Start switch is ON … right now if I disable the PRI-only below staging point, my engine quits. Jeff   I’m curious why you would chose not to use the DPDT switch as suggested.  I think the point is that disabling each set, one at a time, should be part of a run-up check before takeoff to insure all the injectors are working.  Seems a bit awkward to have to do a coordinated switching of the CS switch.   Same issue if you have an injector failure in flight.  Even above the stage point, the CS circuit has to be closed to run with one set disabled.  You’d like to quickly isolate/correct the problem by disabling one set at a time.   Al G     From: "Bill Schertz" <wschertz@comcast.net> Subject: Re: [FlyRotary] More progress, more questions.... Date: Sat, 27 Jun 2009 13:36:36 -0500 To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>

Chris, When you shut off the primaries, the secondary's are automatically turned on.

From: "Ed Anderson" <eanderson@carolina.rr.com> Subject: RE: [FlyRotary] More progress, more questions.... Date: Sat, 27 Jun 2009 07:59:14 -0400 To: "'Rotary motors in aircraft'" <flyrotary@lancaironline.net>

Hi Chris, Just wanted to mention that when you used the "Injector Disable" switch to turn off the primary injectors - the EC2 will then automatically turn on the secondary injectors regardless of whether you are above or below the staging point. They in effect become your primary injectors. This is assuming you have the injector switches wired per Tracy's recommendation and of course the "disable" switch is ON for your secondary injectors. So assuming your EC2 is set up properly the engine should idle on either pair (with perhaps some minor tweaking of the mixture control).