By way of comparison, my carb body temps (i.e. as measured on the
outside of the venturi, not on the heater block) have run at between 23C
and 53C between the hottest and coldest days of UK operation over a
period of 5 years; the latter temperature being untypical and during the
recent record July temperatures of 30C+.
But I don't have the Skydrive carb heater fitted.
Rather, I have the Classic style of rear exhaust header, where the
exhaust pipe passes quite close to the carb. Also, carburettor air is
taken from under the cowl, not from outside, which is undesirable on two
counts, but I have never experienced carb icing.
Temperatures go up during taxiing, down during flight. Hot starting can
be a problem with Mogas.
Next trick is to see what temps. are experienced with external air.
Duncan McF.
----- 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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