Blackbird Sims / Milviz Forum Archive

Hi,

I have a question regarding the cylinder head temperature readout. I use FSX:SE, Win 7 64.

When moving the carburettor heat lever down to HOT, the carburettor mixture temperature gauge shows a rising temperature as expected, since warm air from a heat exchanger surrounding the engine exhaust collector is fed into the carburettor. What appears very strange to me is that the cylinder head temperature (the gauge to the right of the carburettor mixture temperature gauge) at the same time shows a decreasing temperature. This seems rather strange. Heat is used from the exhaust section and delivered into the carburettor. I really would expect that this would cause the cylinder head temperature to rise as well. Or could an increased carburettor inlet temperature have an effect on the combustion, such that the cylinder head indeed becomes less hot? My guess is that there is a sign error somewhere in the algorithm determining the gauge readout, but would like to hear from the experts.

Best regards,

Henry

Warmer air to the carb is going to cause some power loss. Power = heat

HenryW wrote: ↑

Sun Jul 29, 2018 10:24 pm

My guess is that there is a sign error somewhere in the algorithm determining the gauge readout, but would like to hear from the experts.

Hi,

Gauge readout is Ok. Carburetor heat actually makes the mixture richer, therefore reducing Cylinder Head Temperature.
It is a common practice by Beaver pilots, in warm summer days, to use a bit of Carburetor Heat in order to cool engine CHT.

Tomas

Thanks for the feedback, guys. Learned something new again.

Regards,.
Henry