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Have noticed that upon the first flight of the day and climb-out my CHT's can be as high as 410. I watch them pretty closely and do not let them get much above that especially 420. Upon cruise evrything settles down nicely. I will land maybe fuel or have breakfast. On my next leg with the same climb-out parameters my CHT's do not go above 380-390. That's great but curious as to why. Has anyone else had the same experience?

I find that factors such as outside air temperature, humidity, climb airspeed, duration of climb, how hot the cylinders were before you took off, how quickly you dial back your RPM after take off — all those affect how easy it is to manage temps during climbing. For my airplane, I try to keep my cylinders below 400 — if they start going above by even a couple of degrees, I'll change something to drop the temperature. Practically speaking, airspeed and power (MP and RPM) are the only things you can change but some of these compete with each other so which you use might depend on the other factors that you can't change...

The weather seems to be the biggest factor — once I took a consistently-heavily-loaded airplane on a multi-day cross-country trip from LA to Toronto, and as I went further north and east my CHTs became easier and easier to manage.

dwurfel wrote: ↑Sun Nov 21, 2021 11:44 pm Have noticed that upon the first flight of the day and climb-out my CHT's can be as high as 410. I watch them pretty closely and do not let them get much above that especially 420. Upon cruise evrything settles down nicely. I will land maybe fuel or have breakfast. On my next leg with the same climb-out parameters my CHT's do not go above 380-390. That's great but curious as to why. Has anyone else had the same experience?

I have similar issues with my 2003 DA40-180 - I've found best practice has been to transition to a cruise climb at 100-110 knots as soon as practicable after takeoff. That usually gets the temps back below 400 pretty quickly.

In my early days on the forum, I found these threads on CHT management helpful. I'm sure there are others.

viewtopic.php?t=4356
viewtopic.php?t=6926

best,
dan

Thanks Dan and all. I will check those threads out. Mike Busch published a great article and webinar on the subject.

Maximizing fuel flow and carefully eliminating *all* baffle leaks are crucial steps to controlling CHT.
Enabling faster climb rates at relatively low IAS while keeping the cylinders attached.

See: https://www.diamondaviators.net/forum/viewtopic.php?f=24&t=7409

Chris

Don't forget that Arizona kit will change a lot for the old planes.
Mine was with the very first front top left baffle (small inlet hole), I changed to the actual one with the "Arizona kit", and it was really a huge change in CHT.

Arnaud.

Arnaud, where can I get info on the Arizona kit. Google did not give me anything. Thanks

Hi,

Did you try the search engine of this Forum.
I can sent you part number and drawing yes.

Let me try that. Thanks Arnaud

David,

There is this post with the part number and more information about the Arizona baffle in the rest of the thread.