Hi,
We have a mono-wheel XS with 912S and have had the Skydrive carb heat
since first flight, 5 years and 450 hours ago. At first we had the carb
heat on all the time, but after a year or so installed the supplied
water valve because of problems with hot starts in warm weather.
Installing the valve (and turning off carb heat during the taxi back)
cured our hot start problem.
Once we had the valve installed, we were able to carefully measure
time to climb as a check of any lost performance due to carb heat on vs
off. There was no measurable difference in climb performance.
Also, once we had the ability to fly with carb heat off, we found
that we could get carb icing, on the ground and in the air, even on what
seemed fairly moderate days. When the carb temp came down to a few
degrees (C) above zero, carb ice was a definite possibility. Turning on
the carb heat water cured the rough running in seconds.
As others have mentioned, we mounted our carb heat water valve on top
of the port side foot well, with relatively short water tubing runs to
the valve, and ran a stiff wire through the firewall for control from
the cockpit.
Regards,
Terry Seaver
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of Karl Heindl
Sent: Sunday, September 03, 2006 4:09 AM
Subject: Re: Europa-List: Skydrive on/off control
Tim,
That is what I thought, but it is actually not true.
When on the ground, and you have a long taxi run, especially on a grass
field and/or on a very hot day, the hot coolant will cause the fuel to
boil in the carburator bowls. You can easily verify this by looking at
the clear carb vent tube through the stbd cowling door, and you will see
the fuel bubbling up into the airbox. You will not be able to start your
engine at this stage as the carbs are flooded. I've proven it by putting
a clamp on the coolant hose to stop circulation. The local Rotax agent
educated me about the Skydrive. He also claims that because the added
collar moves the carburator further from the engine, it contributes to
vibration problems.
And lastly, I don't believe that hot air and hot fuel going into the
combustion, does not affect engine performance. You have a 914, so you
wouldn't know.
Best regards,
karl
>From: "Tim Ward" <ward.t@xtra.co.nz>
>Reply-To: europa-list@matronics.com
>To: <europa-list@matronics.com>
>Subject: Re: Europa-List: Skydrive on/off control
>Date: Sun, 3 Sep 2006 13:45:58 +1200
>
>
>Karl,
>Just keep the carb heat on all the time, no performance penalty. Having
>a switch is just another thing to go wrong and fix!
>Cheers,
>Tim
>Tim Ward
>12 Waiwetu Street,
>Fendalton,
>Christchurch, 8052
>New Zealand
>
>Ph +64 3 3515166
>Mobile 021 0640221
>ward.t@xtra.co.nz
>----- Original Message ----- From: "Karl Heindl" <kheindl@msn.com>
>To: <europa-list@matronics.com>
>Sent: Sunday, September 03, 2006 12:20 PM
>Subject: Europa-List: Skydrive on/off control
>
>
>>
>>
>>
>>Does anyone know of an inline valve, controlled electrically, for
>>controlling the coolant flow in the Skydrive carb heater ?
>>I know they exist for central heating systems, but are the wrong
voltage.
>>
>>thanks in advance,
>>
>>Karl
>>
>>
>>
>>
>>
>>
>>
>
>
|