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You can have it all.....
- Thread starter dotnmarty
- Start date
Marty,
Yes and No :? but not as a usual practice. I have on a few occasions, first to see if I could, and then a few times in very shallow areas where we were at crawl speed, and to avoid the chance of grounding 2 props, I have shut one down and raised it out of the water and run that way for a short distance.
I tend to believe Dr Bobs theory that to run the single would over the long haul, be detrimental to that engine, when it is really designed to be only half of the propulsion system of the vessel.
Harvey
SleepyC :moon
Yes and No :? but not as a usual practice. I have on a few occasions, first to see if I could, and then a few times in very shallow areas where we were at crawl speed, and to avoid the chance of grounding 2 props, I have shut one down and raised it out of the water and run that way for a short distance.
I tend to believe Dr Bobs theory that to run the single would over the long haul, be detrimental to that engine, when it is really designed to be only half of the propulsion system of the vessel.
Harvey
SleepyC :moon
When i bought the Duck cd-22 cruiser it had a 50 hp honda when I took the boat out for its sea trial I knew it was just barely enough . top speed was 16mph it would just about get on plane with 3 people and gear 12mph The engine was at its top( rpm5000) limits for me .
An alternative for those wanting to save on fuel get the suzuki 60 or 70 that would be a good alternative. Ive been there done that when I upgraded I did so witha 90 Suzuki Great motor the best Ive ever had and Ive had them all from Johnson90, merc 175, force 85, yamaha 115 both 2stroke and 4 stroke In closing get at least a 60 or 75 for single s or for twins get twin 40s and run on one eng
An alternative for those wanting to save on fuel get the suzuki 60 or 70 that would be a good alternative. Ive been there done that when I upgraded I did so witha 90 Suzuki Great motor the best Ive ever had and Ive had them all from Johnson90, merc 175, force 85, yamaha 115 both 2stroke and 4 stroke In closing get at least a 60 or 75 for single s or for twins get twin 40s and run on one eng
Ok, and thanks. But if you take "fast" out of the equation, and, consideriing that twins are "propped to run as twins", what about this--most of the time we just toodle along, just enjoying a day on the water at displacement speed, maybe 8-10 mph, which would be more efficient on a 22footer during those times?
1. twin 40's, both running
2. twin 40's, one down and running, one up and off
3. one 70
4. one 90
5. no appreciable difference
1. twin 40's, both running
2. twin 40's, one down and running, one up and off
3. one 70
4. one 90
5. no appreciable difference
Have twin Honda 40's and have run alot on the single other up. 8-10 mph is not displacement speed instead is just between displacement and plane and would net very poor mileage on either single 40 or twin 40's.
Just returned from cruising 250 miles on Yellowstone Lake fairly lightly loaded and averaged 6.5 mpg. Spent approximately half the time on one moter at 5 mph engine running 2000 rpm. Takes dramatically more rpm for every one mph increase in speed maxing out at just under 9 mph with the moter severely lugged. The Lake is at about 8000 feet altitude so approximately 25% of power is lost. Properly propped with a single 40 I have little doubt the 10 mpg is attainable. Normally we will cruise at between 5 and 6 mph on single and 13 to 16 mph with the twins.
Set up to run at displacement speed only is just not practical in any area where the water can roughen up due to it being just to uncomfortable to run the 22 at displacement speeds in choppy seas. This last week we would have spent our entire time at displacement speed if this wasn't the case.
Jay
Just returned from cruising 250 miles on Yellowstone Lake fairly lightly loaded and averaged 6.5 mpg. Spent approximately half the time on one moter at 5 mph engine running 2000 rpm. Takes dramatically more rpm for every one mph increase in speed maxing out at just under 9 mph with the moter severely lugged. The Lake is at about 8000 feet altitude so approximately 25% of power is lost. Properly propped with a single 40 I have little doubt the 10 mpg is attainable. Normally we will cruise at between 5 and 6 mph on single and 13 to 16 mph with the twins.
Set up to run at displacement speed only is just not practical in any area where the water can roughen up due to it being just to uncomfortable to run the 22 at displacement speeds in choppy seas. This last week we would have spent our entire time at displacement speed if this wasn't the case.
Jay
Marty,
I believe hull speed for the 22 is 5-6mph and that would be the max displacement speed, which is where I would run with one single down and one up unless there were considerable extenuating circumstances. I agree with Jay --
Another issue that will come into play here is where is the documentation for the speed coming from. If it is coming off the GPS input it is "speed over ground (or SOG) and may be dramatically different from the actual boat speed on the water (considering the direction of travel, current speed and direction.
That is a nice feature of the Raymarine setup we have (to be able to see both numbers.) Makes it easy top see if we are going up or down hill.
Harvey
SleepyC :moon
I believe hull speed for the 22 is 5-6mph and that would be the max displacement speed, which is where I would run with one single down and one up unless there were considerable extenuating circumstances. I agree with Jay --
....8-10 mph is not displacement speed instead is just between displacement and plane and would net very poor mileage on either single 40 or twin 40's.
Another issue that will come into play here is where is the documentation for the speed coming from. If it is coming off the GPS input it is "speed over ground (or SOG) and may be dramatically different from the actual boat speed on the water (considering the direction of travel, current speed and direction.
That is a nice feature of the Raymarine setup we have (to be able to see both numbers.) Makes it easy top see if we are going up or down hill.
Harvey
SleepyC :moon
Thanks for the replies guys. I should have stated it better. It is a given that my assumption includes engine(s) to really power the 22 at higher speeds when necessary or desired. It's just that most of our time on the lake or the sound is spent on calm water. I know what you mean about 9mph not being displacement speeds. When we first went out on our 22 footer I was surprised to learn that it was actually on plane. It certainly didn't have the distinct difference we were used to in a deep vee. We love our 16 with one 40, but a friend of mine is looking for 22 and I'm sort of inquiring for him. We do appreciate the useful information.
MartyP
MartyP