O-470 chilled cylinder (Skylane)

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CT583

Pre-takeoff checklist
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CT583
Ok, call me crazy for over analyzing this.. Cylinder No. 5(the forward right) is always incredibly slow to warm up to operating temps. move had a compression check performed, indiction leak test, new spark plugs, but no help here.

I have a JPI-830 and it fortunately shows CHT for all cylinders. For some reason this cylinder is always 40-50deg f cooler than the rest during warm-up and run-up.
Now if I take off it seems to catch up with the rest during climb and maintains a constant 10-15deg cooler temp during flight.
I’ve been told by my mechanic that this is fine and not to worry. I just thought I’d post it here and see if you Skylane pilots had any insight.

thank you
 
CT583 said:
Ok, call me crazy for over analyzing this.. Cylinder No. 5(the forward right) is always incredibly slow to warm up to operating temps. move had a compression check performed, indiction leak test, new spark plugs, but no help here.

I have a JPI-830 and it fortunately shows CHT for all cylinders. For some reason this cylinder is always 40-50deg f cooler than the rest during warm-up and run-up.
Now if I take off it seems to catch up with the rest during climb and maintains a constant 10-15deg cooler temp during flight.
I’ve been told by my mechanic that this is fine and not to worry. I just thought I’d post it here and see if you Skylane pilots had any insight.

thank you
Click to expand...
63 Cessna 182F 0470R #5 not firing at idle | Pilots of America
 
A 40-50° difference isn’t worth worrying about. In cool weather insulating the balance tube may help. Add a #5 cylinder shroud baffle from a 185 will help, too. Lots of Skywagon guys see #5 as the hot cylinder but in mine I have a shroud on 5 and a tall baffle blocking much of 6 to help warm those cylinders and improve cooling at 1 and 2.
 
Stewartb said:
A 40-50° difference isn’t worth worrying about. In cool weather insulating the balance tube may help. Add a #5 cylinder shroud baffle from a 185 will help, too. Lots of Skywagon guys see #5 as the hot cylinder but in mine I have a shroud on 5 and a tall baffle blocking much of 6 to help warm those cylinders and improve cooling at 1 and 2.
Click to expand...

You don’t by chance have a picture of this do you? I’m interested.
 
CT583 said:
I have a JPI-830 and it fortunately shows CHT for all cylinders.
Click to expand...
A common problem with folks that have too much information. Before all that fancy engine monitoring stuff, most airplanes had one CHT probe and often only one EGT probe, and pilots didn't worry because the normal temp differences weren't shown. Now they see it and get all worried. These aircooled engines, with their primitive induction systems, will always have those differences. GAMI injectors can correct some of it, but you'll still see CHTs off somewhat because the cooling is uneven.

I would suggest that if your car had temp sensors against every cylinder and in every exhaust port, you'd see some differences there too.
 
Dan Thomas said:
A common problem with folks that have too much information.
Click to expand...

I had the same feeling. However, it was my wife who pointed out it was running rough. So I cancelled the flight.
It was also the coldest day I’ve flown my (still new to me)aircraft so I went with the cautious route. Now I know
 
My balance tube has been wrapped with a silcone material since I bought my plane 25 years ago. In cool weather fuel condenses in the tube and the result is overly rich mixture to 5 and 6. I added the baffle on 5 to warm it up and cool 1. As a result my temps are very even.
 
Stewartb said:
My balance tube has been wrapped with a silcone material since I bought my plane 25 years ago.
Click to expand...

do you have a picture of this?

I’m enjoying seeing the mods to improve
 
I don't. My balance tube is larger diameter in the section below the prop. It's wrapped with what looks like an orange silicone heat pad material but without any heat elements in it. It may be the same material as the induction rubbers. Wrapping the balance tube is common in Alaska.
 
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Since it occurred on a cold day you may have morning sickness caused by a sticking exhaust valve. You can verify this by noting the EGT. It will be 200 or so degrees colder than the other EGT’s at idle. Fix could be as easy as running Avblend to lube the valve but might require the valve guide to be reamed.
 
Jeff767 said:
Since it occurred on a cold day you may have morning sickness caused by a sticking exhaust valve. You can verify this by noting the EGT. It will be 200 or so degrees colder than the other EGT’s at idle. Fix could be as easy as running Avblend to lube the valve but might require the valve guide to be reamed.
Click to expand...
I’m not familiar with avblend. However, I did try again and added carb heat with aggressive leaning. It began to run a lot smoother during my time in the ground. Once airborne at cruise everything smoothed out. I just suspect it’s a crummy induction system.
 
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