Mailing List flyrotary@lancaironline.net Message #62320
From: Bill Bradburry <flyrotary@lancaironline.net>
Subject: RE: [FlyRotary] parts upgrade; was: What do you think may be happening?
Date: Sun, 24 Jan 2016 23:43:28 -0600
To: 'Rotary motors in aircraft' <flyrotary@lancaironline.net>

I was afraid this would happen…

 

I got the new injector disable switches replaced today and while I was replacing them, I verified that both primary and secondary switches take pin 30 on the EC-2 to ground, so my wiring now seems to be correct.

But unfortunately I also verified that the cold start action does not turn on both sets of injectors.  My engine operates as I described and not as Tracy says it should.

 

With the engine idling at about 1400 rpm, and the mixture at about 14.7, I turned off the secondary and the engine ran a little differently and the mixture went to about 13.0.  When I turned off the primary, the engine died unless I immediately turned it back on.  I normally shut the engine down by first turning off the power to the injectors and that is just the way it acts.

 

I then ran the engine up to 22 inches and turned the primary off and the engine ran just a little differently but made no effort to shut down.  I don’t have much in the way of readings yet at that power because it is too hard to hold the plane with just brakes.

 

Apparently the cold start system in my EC-2 is not working the way it should.  I need to get this repaired but with Tracy out of commission, I don’t know how to affect that.  I suppose it is not too much of an emergency because this has been going on for a long time.  :>(

 

I will try to get some better data by coarsening the prop so I can hold it better.  I just need to get it above 20 inches and 4000 rpm to get it into that range and hold it for at least a takeoff amount of time.

 

Any ideas on how to get the EM-2 repaired?  How long will Tracy be impaired?

 

Bill

 


From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]
Sent: Saturday, January 23, 2016 9:47 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] parts upgrade; was: What do you think may be happening?

 

Sorry to hear that you've got to be cut on again, but maybe you'll at least get an 'upgrade' that will work a little better & last a little longer this time. :-)

On 1/20/2016 12:55 PM, Tracy Crook wrote:

Steve’s description of how the EC2/3 works was correct.

 

Many get this bit confused but The intention with  the disable switch was to use a DPDT switch for the disables.   When in the disable position, the other pole of the switch is used to activate (switch to ground) the Cold Start input to the EC2/3 at the same time.  This eliminates having to turn off the CS switch when disabling a set of injectors and enables the EC2 to operate on either set over the full range of manifold pressures.  The EC2/3 is able to see when you have disabled the primaries and operate the secondary’s  even though engine is operating below stage point.

 

I’ve been out of touch lately and will be for awhile.  Need to have my hip replaced (again).

 

Tracy

 

Sent from Mail for Windows 10

 


From: Bill Bradburry
Sent: Wednesday, January 20, 2016 1:44 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: What do you think may be happening?

 

Steve,

I think my engine dies and has little effect when I turn off the primary and secondary respectively.  I will have to investigate this when I get the switches replaced (I plan to replace both)  I may have something miswired??

It is cold, maybe Tracy is back in Florida and will chime in.

 

Bill

 

From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]
Sent: Wednesday, January 20, 2016 12:32 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: What do you think may be happening?

 

Bill,

 

I have tested the injector disable function with my EC2's.  With the power interrupted to the primary injectors and the cold switch on, the engine runs on the secondary injectors at MAP below the staging threshold.  I don't know the details of how the controller treats the cold switch, but it is possible that with the cold switch on, the controller increases the fuel flow by using both the primary and secondary injectors at MAP below the staging threshold, and doubles the injector pulse width at MAP above the staging threshold.  I remember investigating this when first using the controllers but don't remember the exact details.  My backup system does work at low MAP.

 

Steve

 

From: Rotary motors in aircraft <flyrotary@lancaironline.net> on behalf of Bill Bradburry <flyrotary@lancaironline.net>
Sent: Wednesday, January 20, 2016 11:15 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: What do you think may be happening?

 

Bobby,

I am sorry I was not clear and the reason was that I was not clear myself.

 

The injector disable switches are for in case you lose an injector in flight and the engine starts to run on only one rotor.  You can disable either of the primary or secondary injectors which will take the failed injector out of the circuit.

Tracy says you should test this to make sure that it works.  That is where my question came from.  You can only test the disable switches when the engine is not staged.  If the engine is staged, and you turn off the primary injectors, the engine will die because the secondary injectors are not running, and if you turn off the secondary injectors, the engine will run rich because you turned on the cold start but the secondaries were not running anyway.

 

I am not sure what would happen if you lost a primary injector in flight, disabled the primary injectors, then reduced power to the staging point in order to land???  I suspect all would get quiet!  :>(

 

Bill

 

From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]
Sent: Wednesday, January 20, 2016 11:35 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: What do you think may be happening?

 

Bill,

 

I’m not sure I understand the question.  If your referring to my “center off switch position” it’s not used in flight. Intentionally anyway J It’s used to shut down the engine. Primary injector switch of course. Same switch used for both primary and secondary injectors.

 

Bobby

 

From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]
Sent: Wednesday, January 20, 2016 10:55 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: What do you think may be happening?

 

 

 

Changing the subject a minute…How do you disable the secondary’s when the engine is staged??  They are not running anyway???

 

Bill

 

 




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