Have you ever experienced carb ice with an injector carb?

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: [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

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: [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