Message-ID: <000a01c3fa0c$484d6890$2402a8c0@edward>
From: "Ed Anderson" <eanderson@carolina.rr.com>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
References: <list-3041292@logan.com>
Subject: Re: [FlyRotary] Primer valve?
Date: Mon, 23 Feb 2004 07:55:15 -0500
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----- Original Message ----- 
From: "Finn Lassen" <finnlassen@netzero.net>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Sunday, February 22, 2004 11:57 PM
Subject: [FlyRotary] Primer valve?


> 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)?
>
> Of course the big burning question is: what changed? I did not have
> problems starting before the overhaul.
> I really have to remember to bring my compression tester next time I go
> to the airport.
> Choke passages in carbs clogged?
>
> 1.6 hours in the air today (mostly between 4500-4800 RPM - only one
> radiator). Highest water temp seen today: 98C. I'm trying not to
> overheat it too badly (although during full-power ground run-up Friday
> temps reached 108C after idle or shut-down).
>
> Will try to get new left radiator mounted this week.
>
> Finn

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