EGT or CHT in 912ULS?

[Ultralights]

Gday, i have found a MGL avionics 4 channel EGT/CHT digital engine monitoring instrument in my garage originally intended for my Vampire, anyway, it would be of greater use in my Savannah as the Vampire already has EGT and CHT fitted.

 

so my question is, which would be most benificial in a 912 ULS Powered Savannah?

 

4x EGT? or 4X CHT? bearing in mind it has water temperature monitoring for both Left and Right hand sides, and Oil temps and pressure indicators.

 

Would EGT be more useful in monitoring engine condition and onset of problems? again noteing that Mixture cant be changed in flight to influence EGTs? or would CHT be a better indicator of impending problems?

 

at present im thinking EGT would be a better indicator of engine health.

 

Thanks in advance

 

Rob.

 

 

[Guest burbles1]

I'd like to know this too just to improve my knowledge of engines. What gauges would give the most useful info, and that you'd be able to influence in flight.

 

 

[Powerin]

Just a thought, do the Rotax temp senders measure coolant temp or head temp? If they are only coolant will they show the heads getting hot if you lose your coolant?

 

I just recall in the last RAA mag incident reports there was something about a Subie EA81 engine failing from loss of coolant but the temps were still showing in the green.

 

Peter

 

EDIT: the Tecnam POH says its gauge shows CHT

 

 

[facthunter]

Heads or EGT's.

 

Rob, Seeing as the mixtures are not in-flight adjustable and the heads may not indicate a loss of coolant, I wouldn't be rushing to instal any of that stuff. Oil temp and pressure should cover it. When I have had an overheat in a 912, it's usually green stuff running along the cowl that alerts me and that is coolant going past the pressure cap. Nev

 

 

[jetboy]

4 x EGT because you have 2 carbs and float levels to keep out of balance, far more interesting than CHT

 

Ralph

 

 

[Ultralights]

thats the main reason i was thinking EGTs, to give warning of carby problems, such as leaning due to cracked or loose carby sockets, out of balance etc

 

Nev, recently we had a coolant cap failure, the only reason it was detected was the overflow bottle was filling well above the normal level, we never lost any coolant overboard, though if we did suffer a coolant loss, im sure a CHT sender would detect it happening whereas a EGT, or coolant temp sender might not.