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View Full Version : Have you ever experienced carb ice with an injector carb?


flybynightkarmarepair
January 30th 05, 10:35 PM
This is a cross-post from the AeroVee and AirVW Yahoo groups.

Injector carbs of interest:

AeroCarb
POSA
HAPI SuperCarb
Lake
RevFlow
Ellison

I have found one builder who describes a case of a Sonerai with a POSA
that liked to ice up in Texas.

http://groups.yahoo.com/group/aerovee/message/622

http://escribe.com/aviation/vw/m4920.html

Several others have responded with considerable experience and NO ice.

Anybody else out there?


--- In , jl <jeff@s...> wrote:
Lets do it this way.

Anyone who has had a complete engine failure due to carb or intake ice
with a THROTTLE BODY CARB, say so now.

Jeff

On Wednesday, January 26, 2005, at 05:32 AM, Tony Spicer wrote:

>
>
> ----- Original Message -----
> From: "robert lord" <robertnelsonlord@h...>
> To: >
> Sent: Tuesday, January 25, 2005 10:43 PM
> Subject: Re: [aerovee] No carb heat?
>
>> as someone just wrote their sonex with the cowl offuaing an aeroV
>> carb had
>> ice forming on the outside of the intake tube . What would make you
>> think
>> that a great deal more ice was not forming on the inside where it
is
>> much
>> colder with much more air and humidity being squeezed from the air.
>
> Robert,
>
> And did that "ice" disappear when carb heat was applied? Should you
> choose
> to install carb heat, be sure to do some testing so as to not be
> lulled into
> a false sense of security. Get a remote-reading digital thermometer.
> Mine
> was $12 at Lowes. Comes with a wire that is long enough to easily
> reach from
> engine compartment to cockpit. The thermocouple bead on the business
> end is
> glued into a plastic fitting with a dab of RTV. Use an Exacto knife
to
> carefully pry it out. Now it will fit thru a 3/32" hole. Route it
from
> cockpit to engine compartment. Just upstream of where the scat hose
> connects
> to the carb, cut a small slit and insert the thermocouple wire about
> 1/2"
> into the airflow. Clamp the wire to the duct with a tiewrap or piece
> of duct
> tape. Go fly. Run the engine at 75% power and note inlet temp. Apply
> carb
> heat and note temp. In a certificated aircraft, the FAA requires a
90
> deg F
> temp rise, but in an experimental, there's no requirement. Just
makes
> for a
> good comparison. Next, remove carb heat, pull throttle to idle, slow
to
> pattern airspeed, let things stabilize, and note temp. Pull carb
heat
> and
> note temp rise. Next, and most important, convince yourself that
> whatever
> you saw for a rise is sufficient to prevent ice from forming.
>
> When I moved into the neighborhood, I noticed my neighbors mailbox
was
> painted purple with large white polkadots. Asked him why, and he
said
> it was
> to keep the elephants out of his yard. Been here nine years, and
> haven't
> seen one yet. Must be working.
>
> And to maintain my consistency, I say for the third time "Make your
> decision
> on whether or not to use carb heat based on how you see the facts."
>
> Tony

Ron Webb
January 31st 05, 01:48 AM
I've got an Ellison throttle body on a modified O-360 lyc that is really
touchy. It will cut out suddenly on take off, about 90 seconds after full
power is applied if the weather is right.

A bad feeling to be left with the noise generator not generating. Nice and
quiet though. Cycle the throttle to scrape the ice off the bar and it comes
right back.

I'm re-working the carb heat box this winter.



"flybynightkarmarepair" > wrote in message
oups.com...
> This is a cross-post from the AeroVee and AirVW Yahoo groups.
>
> Injector carbs of interest:
>
> AeroCarb
> POSA
> HAPI SuperCarb
> Lake
> RevFlow
> Ellison
>
> I have found one builder who describes a case of a Sonerai with a POSA
> that liked to ice up in Texas.
>
> http://groups.yahoo.com/group/aerovee/message/622
>
> http://escribe.com/aviation/vw/m4920.html
>
> Several others have responded with considerable experience and NO ice.
>
> Anybody else out there?
>
>
> --- In , jl <jeff@s...> wrote:
> Lets do it this way.
>
> Anyone who has had a complete engine failure due to carb or intake ice
> with a THROTTLE BODY CARB, say so now.
>
> Jeff
>
> On Wednesday, January 26, 2005, at 05:32 AM, Tony Spicer wrote:
>
> >
> >
> > ----- Original Message -----
> > From: "robert lord" <robertnelsonlord@h...>
> > To: >
> > Sent: Tuesday, January 25, 2005 10:43 PM
> > Subject: Re: [aerovee] No carb heat?
> >
> >> as someone just wrote their sonex with the cowl offuaing an aeroV
> >> carb had
> >> ice forming on the outside of the intake tube . What would make you
> >> think
> >> that a great deal more ice was not forming on the inside where it
> is
> >> much
> >> colder with much more air and humidity being squeezed from the air.
> >
> > Robert,
> >
> > And did that "ice" disappear when carb heat was applied? Should you
> > choose
> > to install carb heat, be sure to do some testing so as to not be
> > lulled into
> > a false sense of security. Get a remote-reading digital thermometer.
> > Mine
> > was $12 at Lowes. Comes with a wire that is long enough to easily
> > reach from
> > engine compartment to cockpit. The thermocouple bead on the business
> > end is
> > glued into a plastic fitting with a dab of RTV. Use an Exacto knife
> to
> > carefully pry it out. Now it will fit thru a 3/32" hole. Route it
> from
> > cockpit to engine compartment. Just upstream of where the scat hose
> > connects
> > to the carb, cut a small slit and insert the thermocouple wire about
> > 1/2"
> > into the airflow. Clamp the wire to the duct with a tiewrap or piece
> > of duct
> > tape. Go fly. Run the engine at 75% power and note inlet temp. Apply
> > carb
> > heat and note temp. In a certificated aircraft, the FAA requires a
> 90
> > deg F
> > temp rise, but in an experimental, there's no requirement. Just
> makes
> > for a
> > good comparison. Next, remove carb heat, pull throttle to idle, slow
> to
> > pattern airspeed, let things stabilize, and note temp. Pull carb
> heat
> > and
> > note temp rise. Next, and most important, convince yourself that
> > whatever
> > you saw for a rise is sufficient to prevent ice from forming.
> >
> > When I moved into the neighborhood, I noticed my neighbors mailbox
> was
> > painted purple with large white polkadots. Asked him why, and he
> said
> > it was
> > to keep the elephants out of his yard. Been here nine years, and
> > haven't
> > seen one yet. Must be working.
> >
> > And to maintain my consistency, I say for the third time "Make your
> > decision
> > on whether or not to use carb heat based on how you see the facts."
> >
> > Tony
>

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