New member - Aircraft engine EFI

[Bernd Felsche]

Bruce tapped away at the keyboard with:
> From: "Bernd Felsche" <bernie at innovative.iinet.net.au>
> > Bruce tapped away at the keyboard with:
> > > From: "Jeremy Harris" <Jeremy at UKPilots.net>
> > > > My reasoning for EFI has more to do with weight
> > > > and freedom from icing than fuelling accuracy.
> > > Given the right conditions EFI can Ice up like a carbbie.
> > > Many throttle bodies include an coolant transfer port to prevent this.

> > Yep. Happens at near-freezing temperatures with high moisture
> > content in the air. Fortunately, he's got an air-cooled engine to
> > use for pre-heating the air.

> Shame to have to heat the whole intake tract using that method.
> Mabe circulate some engine, reduction gear box, oil thru the throttle
> bodies.

I'm not sure all that much oil cooling takes place in a BMW engine.
Porsche engines have been oil-cooled since about the 911.

You don't have to take all the inlet air from the cooling air exit.
You mix just enough to read a temperature of about 25 degrees C
which is "ideal" for vapourization anyway.

One could go to a junk yard and get a preheat thermostat with
control flap from a watercooled VW's airbox and hook them up to the
manifold side of the throttle valve for vacuum. The thermostat is
set to open the flap control below 30 degrees C, fully open at about
18 degrees C. It's extra mass on an aircraft (though probably less
than 250g for the components, but perhaps double that again for
ducting and housing), which is why I didn't mention it before.

-- 
Bernd Felsche - Innovative Reckoning, Perth, Western Australia
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