Does trimming lower cowl to increase exit area really lower CHT?

[Toobuilder]

The tape at the hinge line is a simple trick to try before you look for a more permanent fix. I did it on the RV some time ago and was not able to duplicate any positive result, but clearly some have.

[Mike H]

Originally Posted by erikpmort

I'm so glad it's getting cold.

Another year of high chts over. I'm to the point I don't even fly when it's over 80

I did louvers, cut exit, worked on baffles, it helped. But I still can't climb worth beans until oat goes around 70 or lower. 430 can be hit very easily at 125 climb speed with 19" and 2400 rpm. Yeah sucks so I pretty much nurse it up to altitude until it cools off

Anyway end rant. I almost drilled jet and read things that scared me out of it. Otherwise I love my plane. I would pay good money to take it to someone to fix it.

What is you're EGT spread between full rich and peak at say 60-65% power?

[erikpmort]

I did this above 8k full rich wot to lean and I'm trying to remember what the spread was. Say it was 200 what would you tell me to do ? I think I recall from my last experiment I was told to drill to more rich.

[Mike H]

You will need good data first. But if it is a too lean condition I would call Marvel Schebler and tell them what -10 number carb you have and see what carb setting they recommend. I recently "fixed" a 300 hour -9A that was built with a factory new lycoming and ran way too hot in all phases of flight. A new carb and some baffle work did the trick.