Engine longevity and % power

[skelrad]

Forgive the ignorance (I'm just getting ready to get my PPL), but for the typical lycomings used in RV's, what's the general consensus on a max cruise power setting to use. By that I mean, for engine longevity, what should the max continuous power setting be? Is cruising at 75% power typical, 65%, etc? Most cruise performance numbers seem to be listed at 75% - is that setting hard on the engine, or is that what they're made to take in the long-term?

Just curious.

Brandon

[cjensen]

They're made to take max power for 2000 hours. I know a guy that ran his O-360 with the throttle firewalled (except for pattern and landing, of course) for 3,000 hours with no problems whatsoever.

[f1rocket]

Chad's correct. They are made to run full bore all the time. However, one tends to run where the fuel economy makes sense. On longer hauls at higher altitudes, more power doesn't translate into more speed, just more fuel burn.

[Walter Atkinson]

To quote George Braly:

"It's not how hard tyou run the engine; rather, it's how you run the engine hard."

It's not the HP being produced that affects longevity, it's the mixture used to produce that HP that matters.

Walter