On Apr 2, 2005, at 7:31 AM, Mark Ravinski wrote:

Consider the stress when you cob in full power on a cold engine.  There is little or no airflow yet and the flow of cooling oil is minimal.  The rapid heating will distort cylinders and change tolerances.
The Lycoming book says that if the engine responds to advancing throttle smoothly it's warm enough to go.
Like other engine limits - this one borders on abuse.


Mark:

If you have any data to support that contention, I would really appreciate seeing it. I know of no such data and do not share your concern. As a matter of fact, waiting until the cylinders are a higher temperature before takeoff, only serves to end up with a hotter CHT during initial climb. I'd rather keep the cylinders cool. TCM, Lycoming, Pratt & Whitney, and Wright all seem to agree with that. I think they're right.

Walter