Posted for "George Braly" <gwbraly@gami.com>:

Larry,

Something is "wrong".   Unexpectedly HOT induction air should not make the CHTS get hot enough to require a power reduction when one is in icing conditions.

If you are ROP,  hot induction air must makes the mixture RICHER and the CHTS would normally get cooler.

If you are LOP,  then  hot induction air would make the mixture get richer and, conceivably make the CHTS get warmer, but going to full rich climb power would solve that problem.

Regards,  George


 > > > Question... Scott, have you looked at the "automatic" alternate air system
specified in the IV construction manual and found it deficient?

Answer... YES, it's deficient.  The alternate air door does open if
operating correctly; however the hot cowl air causes hot CHT's even at full
rich in most installations.  So unless you want to toast your engine you
have to pull back on the power, not what you want when you're taking on ice
in the soup.  I've been there many times.

Larry Klaas
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