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Re: Priming Engines For Starting
Posted: Tue Jan 31, 2017 8:49 pm
by GlenNJ
I was hoping someone had developed some kind of primer line that would spray fuel closer to the cylinders. At a flight school I used to work at, two aircraft catch fire one winter during engine starts. In both cases, pumping the throttle caused the carburetors to load up with fuel. When the engines backfired, they started a fire in the air cleaners. One fire went out when the pilot kept cranking the engine and got the engine started. The other had to be extinguished (the dry chemical extinguisher did more corrosive damage than the fire did). After that, all students and renters were taught to use the primer pumps to prime the engines.
Glen
Re: Priming Engines For Starting
Posted: Tue Jan 31, 2017 1:06 pm
by Lowrider
Thanks Tony!
Neat install!
Re: Priming Engines For Starting
Posted: Tue Jan 31, 2017 12:52 pm
by at7000ft
ynkster wrote:When I started my 3.0 Corvair at the Corvair Colledge on Williams test stand with a SPA carburetor it fired on the third blade tip, no problem!
Have an MA3-SPA (acc pump) on my 2700 Corvair, usually takes one pump to start when over the mid-50s, took two extra pumps to start this weekend with the temp around 45 F. Nice not having to mess with a primer.
Rick H
Re: Priming Engines For Starting
Posted: Tue Jan 31, 2017 11:40 am
by Tony Spicer
Lowrider wrote:Tony,
Not familiar with the 3300...is that up draft or down draft intake?
https://get.google.com/albumarchive/116 ... 3ZNwdM_fPy
http://jabiruna.com/engines/
Tony
Re: Priming Engines For Starting
Posted: Tue Jan 31, 2017 10:01 am
by Lowrider
Tony,
Not familiar with the 3300...is that up draft or down draft intake?
Re: Priming Engines For Starting
Posted: Tue Jan 31, 2017 9:23 am
by ynkster
When I started my 3.0 Corvair at the Corvair Colledge on Williams test stand with a SPA carburetor it fired on the third blade tip, no problem!
Re: Priming Engines For Starting
Posted: Tue Jan 31, 2017 8:32 am
by Tony Spicer
Glen,
Pretty simple with the Rotec. Open throttle, turn boost pump on, then mechanically or electrically depress bypass button on fuel pressure regulator. Fuel will then flow out all the exposed holes in the spray bar. Close throttle. Three seconds will dump enough fuel that the engine fires immediately when cranked.
The Ellison on my first 3300 had no bypass on the regulator, so a primer fitting was installed in the intake manifold.
Tony
Priming Engines For Starting
Posted: Mon Jan 30, 2017 8:19 pm
by GlenNJ
How are builders of non-Lycoming or Continental engine Panthers priming their engines for starting? Continental and Lycoming carbureted engines usually have a priming pump to inject raw fuel into or near the cylinders for engine start. This is the preferred method to start these engines, as opposed to pumping the throttle and using the carburetors accelerator pump (if equipped), to get raw fuel to the cylinders. The problem with the later technique is with an up-flow air intake, you can load up fuel at the carburetor, which can cause a fire if the engine backfires. How are carbureted Corvair engines primed? Paul and Tony are using throttle bodies on their Corvair and Jabiru engines. How do they prime them? From the pictures I’ve looked at, I haven’t seen any priming lines or ports on either of these engines.
Glen