Just use a standard K or J type welded junction type thermocouple (i.e. two
wires welded together in a small bead). I would be cautious of any other
type of sensor ... they may have too much mass and will introduce lag or
damping into the readings because of the time required to heat the mass of
the sensor housing.

Also don't bond the thermocouple to the carby housing. You want to measure
the air temperature, not the temperature of the metal inlet flange to the
carby.

Just stick the thermocouple wire into the inlet area - depending on the
engine you can loosen a cable clamp in the alternative air system and just
slide it in and retighten the clamp. I would slide in approx 1" of
thermocouple wire so that the thermocouple is somewhere near the middle of
the inlet hose.



Ray Toews wrote in message ...
Thanks for the insightful help, I planned to install some sensors to
check the rise. I think I will glue one rite to the outside of the
carb at the intake for as realistic a measurment as possible.
I use those little automotive outside air temp sensors I buy from
Canadian Tire, I noticed Wally wallmart has them as well but the ones
I bought from wally were celsius only, irritating but not
unsurmountable. They have about six feet of wire and a sticky back
wich seems to hold well.
God bless all the little borocrats who consented to give us the
homebuilt movement.

ray

On 19 Oct 2004 16:55:42 -0700, (Dan
Thomas) wrote:

Matt Whiting wrote in message
...
Steelgtr62 wrote:

Some British engines used an oil passage through the carb venturi, a
far more
elegant solution. However using fuel injection or mounting the
carburetor on
top of the engine instead of underneath would largely obviate the
problem.

Fuel injection will help a lot, but mounting the carb on top makes
almost no difference.


Matt

The Gipsy Major took its carb heat from up next to the
crankcase. As with using undercowl air, the time between startup and
useable heated air is too long and carb ice can form while warming up.
We see carb ice shortly after startup rather regularly here, and
we live in fairly dry country. Need to pull carb heat soon after
startup some mornings. It's a good thing the exhaust piping heats up
quickly.

Dan