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Thomas,
I had a similar problem when I first bought my IV-P - #2 ran hot during
climb, and I could alleviate it a bit by partially closing the oil cooler
door.
The back side of the #2 cylinder is right up against the forward side of the
oil cooler. It doesn't leave much room for airflow. I had a modification
installed (don't know what it is called, but any shop knowledgeable on
IV-P's should know what it is) that added some concavity to the front side
of the oil cooler, providing more room for airflow around the back of the #2
cylinder.
In my case, at the same time we discovered I had a burned exhaust valve on
the #2 cylinder. Whether that was related or not I'll leave to the engine
experts. We also changed the baffling around the prop hub to better control
the airflow. After all was said and done (including an engine overhaul -
different problem) my #2 CHT now behaves and #'s 1,2, 5, and 6 are pretty
close in CHT. #'s 3 and 4 are now my warmest. I still don't have it where I
want it but it is a lot better.
I think your IAS during climb is too low. Try using 165 or 175 IAS for climb
speed and see how that affects things. Using 165 I used to have to level off
at about 13,000' to allow the airspeed to climb and provide cooling air and
time to bring my CHT back down. Once it was trending downwards I would
continue the climb.
You don't mention your MP during climb. I used to (and still do sometimes)
used 31.5" during climb. One suggestion I received was to continue climbing
at WOT. That helped a lot although it uses a lot of fuel. I've also tried
lowering power to somewhere between 27.5" - 29.5" - that also helps.
If you haven't already you should check compression and put a borescope into
#2 to make sure something else isn't going on.
Jay Phillips
-----Original Message-----
From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of
Thomas Whalen
Sent: Wednesday, August 06, 2014 1:20 PM
To: Lancair Mailing List
Subject: [LML] High CHTs on #2, TSIO 550
I have been fighting for over a year to try to keep the #2 CHT below 400 dg
on the climb. It has hit as high as 430. I leave it full rich and climb at
140kts. When I level off, I then LOP and then #1 cools off. I have the
Lancair baffles and RTV the gaps with the engine and have a good baffle
seal. I even covered my 3rd intercooler and that only helped a little.
Behind the prop the baffle seals up to the top cowl but not down to the
bottom. I have seen it the reverse of that as well. If close the oil cooler
door the CHT will drop 5dg at times. This was a factory new engine. Any suggestions?
Thomas Whalen
N444TW
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