My understanding is that the Bing carbs on the 912S are not designed for ram air
- on my Europa I am using the 914 FWD kit on a 912S (I originally planned on
a 914 but the price differences of recent years seems excessive). This has the
advantage of not taking in water during rain or when on the tarmac. The air
box around the NACA inlet is sealed mainly so that only cool air enters the
carbs
- but the air filter box is vented to the carbs so that there is no excess
pressure in the air going to the carbs. The 914 is boosted, but requires
numerous
other gadgets to allow the Bing carbs to function properly with the excessive
pressure.
Gary Leinberger
A237
Lancaster, Pa.
95% done, 95% to go.
________________________________________
From: owner-europa-list-server@matronics.com
[owner-europa-list-server@matronics.com]
On Behalf Of Fred Klein [fklein@orcasonline.com]
Sent: Sunday, June 06, 2010 7:41 PM
Subject: Europa-List: Combustion air inlets
On Jun 6, 2010, at 12:38 PM, Frans Veldman wrote:
While solving my cooling problems, I learned a few things:
1) Naca ducts provide no ram air, but merely "allow air to get in".
To all you 912S powered flyers,
Page 8-1 of the Europa "912 Rotax installation manual" states:
The engine inlet air is fed through a NACA duct situated in the top cowling. It
passes into a plenum
chamber which feeds the air directly to the carburettors. This ensures that the
coolest air available is
used at all times, thus ensuring no reduction of engine performance.
If Frans is correct, it would appear to follow that the 912S plenum does not
offer
inlet air to the carbs under ram air pressure.
And since the 914 engine inlet is a NACA vent also, the same would apply.
I'm surprised...having thought that engine performance benefits when the carb
gulps
air which is above ambient pressure.
Any wisdom to pass on to a heretic?
Fred
A194 (w/ Sube)
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