[C320-list] Low speed under Load

[Jeff Hare]

Brian,

I think the numbers look ok.  Interesting that you can get over 4000RPM.  I
wouldn't think it should go quite that high but maybe your cable is adjusted
to allow that.
The real test is when you are full throttle, calm conditions, can you get up
to or over 3100 RPM? If you can, then I'd say you're in great shape.  
If you can just barely get to 3k, then you're a little over pitched, but
really, being able to get over 3k RPM should be good enough even if Yanmar
says they want 3.4k under load.

I think our boat sees similar numbers in calm conditions.  With our Gori
3-blade, we can get as high as 3.2k under load in Normal, and only 2.7k
under load in Overdrive.
(Overdrive on the Gori is when you start the engine after you've been
sailing and shift to reverse first, then shift to forward.  It is slightly
overpitched for going forward in that case so you get extra bite that's
useful when motor-sailing in light air and want to get to hull speed at a
lower (quieter) RPM.)  A little hard to explain because the gori 3 blade
gearing opens differently than all the other folding props.

-Jeff


-----Original Message-----
From: C320-list [mailto:c320-list-bounces at lists.catalina320.com] On Behalf
Of Amiraults Family
Sent: Friday, July 17, 2015 4:03 PM
To: c320-list at lists.catalina320.com
Subject: Re: [C320-list] Low speed under Load

Jeff:

 

Based on this thread I checked my own performance after last night's no-race
floater. I saw 6.4 knots at 2700 RPM no wind and calm water at less than
full throttle. At the dock under no load I can get over 4000 RPM at full
throttle. The prop is a Kiwi feathering allegedly set for my
engine/transmission at the factory. Assuming that the boats speed and RMP
instruments are accurate, are these acceptable numbers?

 

Brian Amirault

797 Waltzing Bear, too



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