Message-ID: <403A05C8.4040203@netzero.net>
Date: Mon, 23 Feb 2004 08:53:12 -0500
From: Finn Lassen <finnlassen@netzero.net>
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To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: Primer valve?
References: <list-3041732@logan.com>
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Thanks Ed.

As I woke up this morning it occurred to me: a fuel injector is such a 
valve! Of course I don't know if it will flow any fuel at all at low 
pressures like 4 psi. But that is easy to test. And it (they) will fit 
right in!
I can't remember if the chokes on my Mikuni carbs also act like an 
"accelerator pump", but don't think so.
"Cold start" is a relative term. It was close to 80F here yesterday.

Finn

Ed Anderson wrote:

>>In order to cold start the engine I still have to blow a bit of fuel in
>>through a sparkplug hole. I don't particularily facy this procedure:
>>remove cowling and a sparkplug, squirt gas into the hole, put plug back
>>in and cowling back on, and then start and go fly.
>>
>>I have the two injection holes in the center housing blocked off. I'm
>>considering the idea of adding an electric valve between (pressurized)
>>fuel lines to carbs and one of those holes.
>>
>>Anybody got a good source for a solenoid valve (closed when no power)?
>>
>>    
>>
>Finn,
>
>    One possibility on the cold start problem.  Even with an injector to
>squirt fuel (regardless of air flow) into the intake runners, I have found
>starting on cold mornings takes a bit of cranking.  When I had injectors in
>the block it was no problem, but when I moved then away from the block the
>problem on cold mornings be came a bit more problematic.  I suspect that
>with a carburetor which is dependent on air flow for proper fuel metering,
>low air flow during cranking might make it more of a problem.  Don't know
>whether you have anything like an "accelerator pump" on your carburetor, I
>suspect not.
>So if you have low cranking rpm or possibly an air leak that would reduce
>fuel metering, that possibly could contribute to the situation.
>
>Regarding a solenoid, the Lycomings often have a primer pump for cold
>starting.  In some cases this is manual plunge pump but they also sell
>primer solenoids which are electrically controlled.  Check AirCraft Spruce.
>
>Ed Anderson
>  
>