Hi! Richard
I find myself a little bemused why the resistance to fitting a Manifold
Pressure Gauge, apart from needing room on the panel? If you have a CS
installation without the gauge you will have no indication as to how you
are loading the engine, that is to say RPM is no longer an indication of
power.
So it becomes possible to run the engine at all RPM in a labouring
condition not to be recommended for cruise configuration with respect to
fuel consumption and engine well being. My MT CS prop. will hold the
engine RPM at say 2,500 even with maximum MP at say 30 inches, where
maximum recommended is about 22 inches. The rule of thumb is so called
"squared"
Which means 24" FOR 2,400 rpm ON A DIRECT DRIVE ENGINE. However I've
managed to identify on the Jabiru 3300 that a lower MP with a slightly
higher RPM gives a better fuel performance. (no snipes about fuel usage
comparison with the Rotax thanks Duncan the scenario still applies)
Problem without a MP Gauge is knowing the effect of the ambient and
altitude changes and in pressure relative to engine performance.
Regards
Bob Harrison G-PTAG Europa Kit 337 MKI/Jabiru 3300
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of Richard
Holder
Subject: Europa-List: Manifold pressure gauge
Hi, just received the Dec 2004 issue of the Europa Flyer.
I am very interested to see that Brian Allsop managed to get his Kremen
CS/VP prop approved without a manifold pressure gauge.
When I put my Airmaster on my aircraft at the initial build I saw that
Airmaster and Rotax did not require a MAP and so built my panel
accordingly.
When it came to the Permit to Test Fly Donaldson INSISTED on the fitting
of
a MAP. I argued that there was no requirement from the manufacturer of
either bit of kit. He insisted. Sending me a copy of some JAR "minimum
equipment" list which showed that a MAP was required for a CS prop.
Probably
written in 1948 !
Anyway he is the king of this stuff and I had no option but to fit it
(spitting !) on a sub-panel that destroyed the looks of my panel.
Actually it is very useful for setting power.
So how come Brian didn't need one ? It is only required for CS props -
not
VP props.
I am interested about the description of VP and CS in the article. The
Airmaster gives a VP option just as an aside. I have not used it yet.
The
Airmaster controller has switched positions for Take-Off (5700 rpm)
Climb
(5400) and Cruise (5000) plus a position where you can set any rpm you
want.
The Kremen seems to be a mixture of CS and VP almost as separate
functions,
when really the CS could be used all the time if all the required
features
are there.
Unless someone disagrees !
:-)
Richard
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