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High EGT on right side

mike newall

Well Known Member
Sponsor
First hours on a new RV12.

Right hand EGT is around 40 degrees higher than left. As you throttle back, the EGT rises.

At idle, around 60 degrees higher.

Any ideas ?

CHT is within 4 degrees between sides.
 
There is nothing magical about matched EGT's from one cylinder to another. You are only concerned about that EGT compared to how that EGT normally reads. Minute variations in probe placement lead to relatively huge variations in EGT between cylinders, even if the CHTs read close to the same. Thus, only pay attention to it if that EGT is reading something significantly different than what it normally reads. Mike Busch has written a lot about EGT, in Sport Aviation and elsewhere. Good luck.
 
Mike,

Just a few thoughts.

I suppose before digging in and troubleshooting in earnest, it would be an easy matter to swap the temperature probes and determine if the right probe itself is really reading high or not.

Next would be verifying the wiring back to the engine monitor has no issues.

If the temp probe/wiring is proven to be good, the carbs would be next. Your symptom would be the right carb is running leaner than the left ... (or the left carb is running richer than the right). Assuming a lean carb, that could be caused by an intake air leak on the right side ... or the right carb is actually running leaner than the one on the left.

You would want to verify the clips attached to the needle jets are at the same location on both carbs. Also make sure there is no dirt or debris in the carb that may be partially blocking the main jet. Re-verify the carbs are balanced .... perhaps use a higher RPM say 3800 to check the high speed carb balance.
 
also check that both of the carb pistons slide without friction. I have cleaned and lubricated mine which has eliminated the type of difference in EGTs that you are seeing (ie one of them was sticking creating out of balance conditions)
 
Flew again today, all well at high power.

Testing the autopilot reversions, ended up at 15,000'.....as you do.

EGT's all OK, high on the descent on partial power so may be related to balancing and low power mixture.

Was a tad chilly at -13c but the heater was excellent !
 
Induction leak on that side? Bad balance of carby?

Intake leak is always my first call especially when you say it gets worse as you reduce throttle.
 
Mike, was the 15,000? DA? I?ve Clawed my way to about 13,500? DA with 12,500? indicated on a cold winter day.
 
It was 15000' !

Was doing autopilot speed reversions and wanted to see what happened as it got higher. It stopped at around 12,500, so the rest was manually flown. Re installed autopilot when level and it was fine. Then did the high speed reversion tests on the way down. Interesting to see that the speed scale reverts to TAS at altitude wrt Vne - very clever !

2019092011001944-7443208731856292419-IMG_6938-M.jpg
 
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