On Fri, 28 May 2004 13:54:40 +0000, marbisiNsP wrote:

I have a 30' Sea Ray Weekender with straight, 260HP, 5.7L inboards. Currently,
the boat cruises at about 20kts at 3,100 RPM's. At this speed, I get reasonable
fuel economy, because it's not until about 3,200 RPM's that the secondaries join
the party and start tapping the keg, if you will.


Hi,
Just thought of something as I was going over the Coquihalla Hy and slipping
in and out of overdrive...

First, I hear you about the noise. I like running my Campion at around 3K
partly because of the noise. Sorry, can't help you there. But...

The secondaries really open because of THROTTLE setting, not RPM, correct? So
how about this: DECREASE your prop pitch. Then you're running at a higher rpm,
where the engine puts out more power at lower throttle setting. I suspect you'll
be able to get that few more knots to get fully on plane at a lower throttle
setting than with the "steeper" prop.

Worth a try...

Lloyd Sumpter
"Far Cove" Catalina 36