912 uls EGT differential

by Stephen Pattinson in General Tech Discussion 12 years ago

Appreciate your thoughts on temps on P&M trike and 912uls. Currently have quite a significant differential in cruise between EGT's. 2 are running at about 670c/1240f and the other 2 at 760c/1400f. I am not sure whether the 2 running cooler are closest to prop or closest to air intake. My oil temps with thermostat rarely gets above 90c and CHT's are low at about 80c. My pitch has been too coarse as I only got 5000rpm on takeoff and climb out and I typically cruise at 80mph at 4400rpm. I have just changed the pitch and will now get 5250 to 5300 in the climb but still only cruise at 4550rpm straight and level. So I know I need to get oil temps up to at least 100c in flight and will use a oil cover to do so. Anything to worry about with the EGT differentials. I am hoping they will now be closer due to higher cruise but there will still be a difference.
Engine new with only 35 hours and all plugs show perfect color.

Re: 912 uls EGT differential

by bill martin » 12 years ago

bill martin

10 757 0

Steve,

That difference in EGTs is not bad but it could be better. Two things that might help bring the EGTs closer would be (a) make sure the carbs are balanced pneumatically and (b) take out a little prop pitch and get your WOT up to around 5500RPM. Your engine will love you if you get the cruise RPM up a little higher.

Bill.

Thank you said by: Stephen Pattinson

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Re: 912 uls EGT differential

by Stephen Pattinson » 12 years ago

Stephen Pattinson

3 6 2

Just thought I would follow up with changes and results. I re pitched prop to enable 5300 on climb out at WOT. Now get 5500 at WOT straight and level. Cruise rpm now at about 4900 to 5000 and EGT s now a lot more balanced around 740 to 780. Engine happier and smoother. CHT s still quite low at 84/78 and oil temp at 90.
My climb out now much stronger and although I burn a bit more in cruise, far better to have balanced EGT s and happier engine.

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