Svein,
I have the flow control valve installed in my Skydrive system which I
find very useful. Throughout the summer months it is generally off,
because, unless it is very humid, or I am passing through cloud, I do
not believe there is much risk of carb ice. However, if it is left on
in the summer, it can cause problems with fuel vaporisation, when trying
to re-start after stopping the engine for a short while, (e.g. a fuel
stop).
When I had my first set of carb heaters, it was supplied with a
temperature gauge as you describe, so I was able to use the valve to
control the carb temperature in the winter months to about 30 to 40
degs. My latest heaters (with my new engine) do not have the drilling
for a probe, so I have to guess how much to open the valve in the winter
months.
If you use a change-over switch and another probe you can have the
choice of OAT or carb temp at the flick of a switch.
Best wishes,
William
----- Original Message -----
From: Sidsel & Svein Johnsen
To: Europa List
Sent: Sunday, August 20, 2006 8:56 PM
Subject: Europa-List: Carb. heater block temp.
Having completed the ground testing and awaiting CAA inspection, I
have time to contemplate on one observation made:
The temp. indicator that came with Skydrive's carb. heater blocks for
912S shows block temp increasing as the CHT readings increase. When
reaching 50 degr. C, the indicator flashes HHH (as it is supposed to do
at this temp.).
According to Skydrive's notes, the carb. heater block temp normally is
between 20 and 50 degr. C. This is, I take it, in flight.
Here are my questions to those already flying with this equipment:
- Do the blocks cool down when airborne and operating the engine at
normal flying loads, i.e. when the higher fuel volume evaporation cools
the carburetors from the inside? Or does your temperature reading
always stay below 50 degr. C even when taxiing on the ground?
- Have you fitted any permanent restrictor in the branch-off tube to
the carb. heater blocks, or fitted the flow control valve that Skydrive
provides as an option, in order to keep the carb. heater block temp. in
the range mentioned by Skydrive?
Best regards,
Svein
A225 - now in Norway
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