EGT vs CHT

[justin.schoeman]

Just remember, CHT and EGT show completely different things.

CHT measures the actual temperature of the combustion chanmber, and is effected by a number of things, primarily:
-cooling (air and water)
-lubrication
-combustion temperature (weak dependancy, and slow to react)

EGT measures combustion temperature, and is primarily effected by:
-mixture

EGT barely responds at all to CHT changes (i.e. cooling and lubrication).

So, personally, I would ALWAYS use a CHT, and add the EGT as the optional extra. CHT needs to be monitored and controlled during a climbout on a hot day (in most installations). With only an EGT you could heat sieze the motor without even realising there was a problem.

-justin

[Morph]

Something I learned from Lamercyfly. If you are on a long decent, or during normal straight and level flight you notice your EGT's going through the roof and moving the throttle to a different setting doesn't help then open the choke. This will richen the mixture and cool the engine. Obviously the engine performance is going to drop and you should start looking at doing a precautionary landing ASAP, but at least you hopefully will not damage the motor. Bring the temps down and close it again. Continue to do so until you can land safely and find out what the problem is.

This would be cracks in rubbers, cracks in fuel hose, blocked fuel filters, anything resulting in less fuel and more air getting into the system

[wingnut]

Thanks Morph, now it makes sense to me again.

[Duck Rogers]

Something I learned from Lamercyfly. If you are on a long decent, or during normal straight and level flight you notice your EGT's going through the roof and moving the throttle to a different setting doesn't help then open the choke. This will richen the mixture and cool the engine. Obviously the engine performance is going to drop and you should start looking at doing a precautionary landing ASAP, but at least you hopefully will not damage the motor. Bring the temps down and close it again. Continue to do so until you can land safely and find out what the problem is.

Good grief! Did you get a sneak preview of my story in the forthcoming Afskies mag?

[Morph]

Nope, but definately looking forward to it

[German]

Thanks Morph