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

[RONALD HODEL]

Yes, indeed. I NEVER would have gotten the two apart
Ron

Sent from my iPad

> On Jul 5, 2021, at 8:16 AM, Joe Luciano <jnluciano at comcast.net> wrote:
> 
> If you choose to carry a spare mixing elbow, better carry the entire assembly from the exhaust manifold that bolts up to the engine on one side and clamps to the hose on the other side.  Otherwise, you will never get the pieces apart on your boat, unless you carry a large vise and a big cheater pipe / hammer.  I just changed mine for the second time, needs to be done in a shop environment.
> 
> Joe Luciano 
> #1024
> 
> Sent from my iPhone
> 
>> On Jul 5, 2021, at 7:51 AM, RONALD HODEL <ronandgail2 at me.com> wrote:
>> 
>> Happy (now 5th) of July,
>> 
>> In answer to concerns about running at lower RPMs, the only thing I might add to the discussion is carbon buildup in the exhaust mixing elbow. We bought our boat used and I don’t know if it had ever been changed, but on our trip to Mexico I ran at 2000-2200 RPM ostensibly to save on fuel as fuel wasn’t available everywhere we went. (I knew that was too low an RPM but even with 20 extra gallons of fuel on deck, our motoring range is still quite limited.) About 1/2 way through the trip I had to replace the mixing elbow as it was restricting exhaust flow. If/when we head south again to where the butter melts I’ll add a spare elbow to my spare parts on board. It is considered a consumable. 
>> 
>> Ron Hodel
>> #1070 Lokomaikai 
>> 
>> Sent from my iPhone
>> 
>>>> On Jul 5, 2021, at 7:25 AM, Dick Walker <dickwalker at att.net> wrote:
>>> 
>>> 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
>>>>> 
>>>> 
>>> 
>