Piper Arrow 180 Climb CHT

Tan

Tan

Pre-takeoff checklist
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TheCapTan
Been noticing an increase in my Climb chts. Anyone hitting 400 during the climb with OAT of 70? My number 2 gets in the 400s until cruise.
 
Seems a bit high for a front cylinder. Do you climb at full rich or do you lean?
 
Cherokee derivatives usually have #3 as the hot cylinder on climb. What are the rest of them doing?
 
Either shallow up your climb or step climb.
 
There’s nothing wrong with temps to 425° or a little higher in climb. Lycoming recommends 400° or less for 65% power in cruise to maximize engine longevity.
 
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In my Decathlon, the rear cylinders (3 and 4) are about 30 deg hotter than the front cylinders. Same engine and similar cowling/baffle setup to an Arrow. Front cylinders get more and cooler airflow, so should run cooler. I would investigate further to understand why. Start by decowling and looking closely at the baffles.

FWIW I get 390-400 on the rear cylinders in climb, and 360-370 on the fronts. But a Decathlon has much lower power loading so the engine is not working as hard to climb.
 
Power loading is a flight thing. Engine loading is controlled by the pilot. At 2700rpm the engine is making max power regardless of aircraft weight.

Read the Lycoming operating manuals and bulletins. The OP’s temps are normal. If this temp is a new development? My response would be to run some isopropyl fuel dryer and see if it changes the temps. Or drain the carb bowl and capture the fuel to look for even a tiny bit of water. A few drops of water in the carb bowl will interfere with fuel flow. The first thing you’ll notice is a slight change in engine temps.
 
Hang 4 said:
Cherokee derivatives usually have #3 as the hot cylinder on climb. What are the rest of them doing?
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Ive heard of a few other Arrow owners with #2 being the hottest.
 
It’s a pressure cowl. The air flow from top to bottom is what does the work.
 
Tan said:
Ive heard of a few other Arrow owners with #2 being the hottest.
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I would make sure the temperatures shown on your engine monitor correspond to the correct cylinders before just accepting that. The first step to fixing a problem is determining that you have one, and making sure you’re working with quality data is part of that process.

As was mentioned, the #3 cylinder is often the hottest on a 4 cylinder Lycoming. I’m not suggesting that your information is wrong, but information that doesn’t align with that is common enough I would be even more motivated to check the setup than normal.
 
Personally, in my Warrior, I avoid cylinder temps above 400F. It's not difficult.
At 380F I shallow the climb or level off until cylinder temps drop, then resume climb.

In the past few years, Lycoming has revised its engine operating CHT recommendations to a 400F limit.

Leaning Lycoming Engines

Revision “D” to Service Instruction No. 1094 supersedes all previous recommendations and should be used for engine leaning during normal flight operations. All leaning recommendations are based on calibrated instrumentation. Lycoming strongly recommends that all engine instrumentation be...
www.lycoming.com www.lycoming.com
americanflyers.com

Cylinder Head Temperature (CHT) vs Exhaust Gas Temperature (EGT) | American Flyers

Discover the secrets behind cylinder head temperature (CHT) and exhaust gas temperature (EGT) gauges, and how they help pilots manage engine efficiency.
americanflyers.com americanflyers.com
 
mondtster said:
I would make sure the temperatures shown on your engine monitor correspond to the correct cylinders before just accepting that. The first step to fixing a problem is determining that you have one, and making sure you’re working with quality data is part of that process.
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Yup, make sure the EM installer did not use Continental numbering, which is backwards from Lycoming. On Lycoming the #2 cylinder is in the front. On a Conti it is in the rear. Rear cylinders are normally cooler hotter on 4 bangers.
 
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Tan said:
I climb full rich. My number 2 is always the hottest cylinder.
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I have the same issue in my Warrior with number 2 hitting 450 degrees. I level off until temp drops and then resume climb. Some pilots have reported some temp drop with new baffling from a company in Alaska. Other owners have put a spacer on shielding to number 2 cylinder (legality of this is unknown) and shaved a few more degrees.
 
kshaw said:
I have the same issue in my Warrior with number 2 hitting 450 degrees. I level off until temp drops and then resume climb. Some pilots have reported some temp drop with new baffling from a company in Alaska. Other owners have put a spacer on shielding to number 2 cylinder (legality of this is unknown) and shaved a few more degrees.
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Is this only when it’s hot outside. How about during cooler weather?
 
kshaw said:
I have the same issue in my Warrior with number 2 hitting 450 degrees. I level off until temp drops and then resume climb. Some pilots have reported some temp drop with new baffling from a company in Alaska. Other owners have put a spacer on shielding to number 2 cylinder (legality of this is unknown) and shaved a few more degrees.
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Do it.
 
kshaw said:
Other owners have put a spacer on shielding to number 2 cylinder (legality of this is unknown)
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That would fall under definition of minor alteration, IMO, and thus be legal with logbook entry by A&P. Though I suspect it would also fall in the category of a tree falling in the forest.
 
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