CHTs - What is acceptable?

Dan Thomas wrote:
: http://www.airweb.faa.gov/Regulatory...e?OpenFrameSet

: These are the Type Certificate Data Sheets (TCDS) for US made
: airplanes, engines, propellers and appliances (equipment such as
: Carbs, seat belts and so on).
: Engine TCDS give CHTs and a lot of other stuff. The statement by
: the engine guys that the airframe manufacturer sets CHTs is
: misleading.

: Dan

While the TCDS might contain the max CHTs and such, many people believe that
they are insane. The metalurgical changes that occur when you run a cylinder up to
the "approved" TCDS limit of 500 degrees are significant. Remember that once a TCDS
is approved, it's basically gospel and can never be changed.... in other words, it's
guaranteed to be wrong forever.

Different airframes' engine limits shouldn't be compared directly, but I know
I would try to take the lowest of all of them as a recommendation. The guys who know
engines say that running over 400 in cruise is bad.

-Cory

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************************************************** ***********************
* Cory Papenfuss *
* Electrical Engineering Ph.D. Graduate Student *
* Virginia Polytechnic Institute and State University *
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