[C320-list] Optimal Speed and Lower RPM concerns- Yanmar 3GM30F and Autoprop

[Dick Walker]

Thanks for the quote. I had the auto prop for 20 years it has been very good.

Cheers



Dick Walker
740 Olive Ave.
Coronado ,CA 92118
619.985.8105



> On Jul 5, 2021, at 06:40, John Morrison <sail-ability at sympatico.ca> wrote:
> 
> I have a Campbell Sailor fixed 3 blade prop. Hull speed is reached at 2000rpm and the Yanmar diesel seems very happy at that speed, very smooth! I tried a Flex-O-Fold prop on the boat and it was a disaster, vibrated like hell at cruising speed!
> Regards
> JohnM 
> 1999#574
> 
> Sent from my iPhone
> 
>> On Jul 4, 2021, at 8:42 PM, David Cushman <ittips99 at comcast.net> wrote:
>> 
>> I recently installed an Autoprop of the size recommended by King Propulsion. We just completed an 8 day trip with some days that had significant motoring and  I am extremely happy with the performance over the three blade fixed that came with the boat. My boat speed and the engine RPM closely match the data furnished by Dick Walker, previously posted on this discussion forum. I notice that my fuel consumption seems to be higher at each RPM setting than when using the Catalina standard factory wheel. This makes sense to me. It is still much better economy than before. What have users found to be the optimal cruising speed for fuel economy on longer trips? Are there any concerns running the Yanmar 3GM30F at the lower RPMs since hull speed is met and the much higher RPM is no longer needed? I know that diesels are supposed to run under adequate load and I have read several blogs with slightly mixed messages. To me it seems that the feathering of the prop assures that the self pitching keeps the engine properly loaded at the lower RPM. Opinions and observations are welcome.
>> 
>> Dave Cushman
>> 
>> It Tips
>> 
>> #628
>> 
>