That's odd. I've never seen my carb temp go below 18C (+6C gauge correction
= 24C); the probe is bonded in to the side of the carb. But I don't have the
carb heater. Rather, the proximity of the (Classic style) exhaust header and
under-cowl air intake.
I'd like to take air from outside, (which results in +400rpm on staticengine
speed!) but haven't had the confidence that this would not result in icing.
I seem to recall others reporting icing at much higher carb body temps.
Your data is useful. Thanks.
Duncan McF.
----- Original Message -----
From: "Terry Seaver (terrys)" <terrys@cisco.com>
Sent: Tuesday, September 05, 2006 8:50 PM
Subject: *** SPAM *** RE: Europa-List: Skydrive on/off control
> <terrys@cisco.com>
>
> Hi Duncan,
>
> We did not have carb ice very often, and as I recall, the carb temp was
> always just a few degrees above 0 degC. I am not an expert in this
> area, but I believe you are referring to air temp when you say 20C. The
> carb temp (at certain throttle settings) associated with icing would be
> close to zero due to the venturi effect. We can see the carb temp
> change considerably (5+ degC delta, as I recall) as we go from cruise
> power to idle, for example. The carb temp gauge we are using is the one
> that came with our Skydrive kit, and plugs into the supplied heating
> block.
>
> Regards,
> Terry Seaver
>
>
> -----Original Message-----
> From: owner-europa-list-server@matronics.com
> [mailto:owner-europa-list-server@matronics.com] On Behalf Of Duncan
> McFadyean
> Sent: Tuesday, September 05, 2006 12:16 PM
> To: europa-list@matronics.com
> Subject: Re: *** SPAM *** RE: Europa-List: Skydrive on/off control
>
> --> <ami@mcfadyean.freeserve.co.uk>
>
> <<When the carb temp came down to a few
> degrees (C) above zero, carb ice was a definite possibility.>>
>
> I thought ice was a possibility at any carb temp below 20C?
> Have you experienced carb ice at carb body temps much above 0C too?
>
> Duncan McF.
> ----- Original Message -----
> From: "Terry Seaver (terrys)" <terrys@cisco.com>
> To: <europa-list@matronics.com>
> Sent: Tuesday, September 05, 2006 5:32 PM
> Subject: *** SPAM *** RE: Europa-List: Skydrive on/off control
>
>
>> <terrys@cisco.com>
>>
>> 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
>> To: europa-list@matronics.com
>> 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
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>
>
>
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