I concur with Jerry's email on prop settings. I'm not confident about
prop. ground clearance with a larger dia. though.
BWFX delivers around 5500 rpm (Flydat reading), straight and level at
full throttle, and returns around 133 knots true.
(GPS). Climb rateis good in winter and when light, and poor in summer
at AUW.
I'd always felt that I'd erred on the 'course' side, but in the light of
the discussion, and my own observation regarding
the climb/cruise compromise, I'm not so sure now.
I've just fitted the plenum mod to my standard 912 'classic' monowheel.
Static and climb RPM are higher. Initial indication are of an increase
of around 70 RPM.
to around 5080 RPM static and 4870, steady climb.
I never really noticedthe drop offin revs. on a warm summers day.
However, if I'm ever stuck in the take off line at a busy airfield and
have spend 15 minutes at idle revs, awaiting authority
to depart, I'll feel more confident that the carbs are breathing air at
ambient and not at high, under cowl temperatures.
The climb rate may have improved, it's difficult to tell at this stage.
I'll know moreby July !!
alan
----- Original Message -----
From: Jerry Davis
Subject: Re: Prop Settings
Ben
You didn't state your propeller type but I suspect its the standard
Warpdrive probably on the 912. The standard propeller is in my opinion
too small a diameter to give the best take off and climb on a Europa.
Like all things in life its a compromise. I have several customers now
who have fitted 64" props to their classic Europas and they report
improved climb without any great loss in cruise performance. When
assessing cruise performance I would not recommend simply recording the
rpm as this gives no real guide on power usage. You would have to also
know the manifold pressure or fuel consumption. I reckon that top speed
is a good measure of performance. An aircraft with a max straight and
level speed of 135 kts probably cruises more efficiently at 120 kts than
an aircraft with a top speed of 130 kts.
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