dual 40s hp or single 90hp engine?
- Thread starter jcwiggins
- Start date
I've had both two 40s and currently one 90 with a kicker. I would make sure the kicker can be operated from the helm in Sterling and throttle. Sometimes you just want to putt and don't need the main. In addition, having the kicker could also work as a generator if set up properly.
Hello J C, welcome to the forum.
This is a much discussed and favorite topic of mine. Most of us in our area go with twins or a main + kicker motor for the safety afforded by reduncy.
Either system is the right answer.
I like twins because...well...our boat came with them. In my defense they look cooler and more important. :roll:
If you are buying new have you looked at Marinaut boats?
This is a much discussed and favorite topic of mine. Most of us in our area go with twins or a main + kicker motor for the safety afforded by reduncy.
Either system is the right answer.
I like twins because...well...our boat came with them. In my defense they look cooler and more important. :roll:
If you are buying new have you looked at Marinaut boats?
potter water
New member
Are you happy flying on an aircraft with one big engine on one wing and a little one on the other? Twins are the only way to go. 50's aren't going to cost much more than 40's. Fuel injected for sure.
But the person who commented "whatever the used boat has on it" is a good comment. If it comes with a good single and kicker, you are golden. If re-powering, think of the airplane engine analogy.
Good luck.
But the person who commented "whatever the used boat has on it" is a good comment. If it comes with a good single and kicker, you are golden. If re-powering, think of the airplane engine analogy.
Good luck.
potter water":30wlf6kl said:
I can see good points for both single/kicker and twins, and I don't really follow your argument here.
I'm not really happy flying on any aircraft, but if I am flying I like the idea of two engines in case of failure. If the plane were designed for one larger engine and one smaller one, I'd be fine with that. Likewise with two same-sized engines. Obviously if a plane were designed only for two same-sized engines, that is what I would want.
But from what I have read, the C-Dory design will happily support either two same-sized engines (twins) or one larger and one smaller one (single with kicker). Or even just one single if a person has no need or desire for a kicker. All three are within the boat's design parameters (albeit most modern two-engine combinations are a bit over the weight originally envisioned).
In short, I don't see any of the three choices as being inherently negative.
C-Hawk":2m8l4p0i said:
I'd be interested to hear what you find the handling differences to be (beyond the obvious difference of two throttles, etc). And were there any other differences that may have influenced the handling? Different trim tabs or Permatrim, etc.
Since you've had two 22's, one with each combination, that would be a really interesting comparison. Nice, relatively controlled experiment.
potter water":mhn98baj said:
I am far from an expert on general aviation, but I had an uncle who was. His thoughts, are substantiated by modern experience that a modern single engine aircraft in inherently safer than one with twins. Without going into all of the arguments, I submit this from one of several articles on the Internet:
"The same problems exist today in all twin engine propeller driven aircraft, thus the higher rate of fatal accidents in twins. Even those few with auto-feather and rudder boost are not immune to the laws of aerodynamics, and the incorporation of these features only serves to underscore the inherent danger.
To digress further on the perils of twins; remember, if the pilot is current, well trained, and does everything perfectly upon the failure of an engine after takeoff and succeeds in keeping the aircraft right-side up, many twins, especially at high gross weights, lack sufficient power to climb on one engine and are going in anyhow, under the marginal control and high Vmc of reduced power on one engine."
You cannot equate twins on air craft with boats--but the aircraft argument does not hold water...or even air.
I happen to choose a single and a small kicker which doubles as a dinghy motor. Modern engines are so reliable, that failure is very rare. Most of the time it is bad fuel, or similar issue, which will affect twins as well. Good maintenance will win the day . The single is slightly more efficient. (Prop and lower unit drag is less).
As for handling--My personal experience is that larger vessels with counter rotating inboard twins are definitely easier to handle in tight quarters, but a single can do all of the same things if the skipper is skilled. My only outboard boat with twins was the Tom Cat--and there was a very good reason for twins in that boat. I currently own a cat with a single, and can maneuver it just as well as the Tom Cat with twins. Using prop torque and walk in a single will allow you to dock in some difficult situations.
However, I have to agree; if the used boat has twins, then keep them. I personally would not go out of my way to buy a C Dory with twins, but that is just my opinion, and many owners prefer twins.
potter water
New member
I was just joking fellas! Obviously aircraft and boats are entirely different animals. My boat had twin Suzies on it when I bought it, so I like twins. If it'd had a single and a kicker I'd have bought it. Given identical boats with twins or single plus kicker, I'd take the twins for sure. More power when down to one engine is just better during those rare times when a modern outboard fails.
And yes, the probability of an engine failure doubles with two engines.
The point to take away for people looking at C-dorys and the use most are put to is you really need to consider a reasonably powered back up kicker. I'm less concerned about engine failure than I am about hitting something submerged and loosing a prop at a bad time...or worse a bottom end.
When shallow or with drifting crap, with my twins, I pull up one engine.
I certainly agree after having 3 boats with kickers that putting remote controls on, including start is a really good idea. Having to run back, drop the kicker, start it, and then get it in gear and then manage it from the back is no good at all. Oh, well, as long as you are putting in all of the remote stuff and starter etc. why not just get a much smaller big motor and a bigger kicker...like say...twin 50's.
And yes, the probability of an engine failure doubles with two engines.
The point to take away for people looking at C-dorys and the use most are put to is you really need to consider a reasonably powered back up kicker. I'm less concerned about engine failure than I am about hitting something submerged and loosing a prop at a bad time...or worse a bottom end.
When shallow or with drifting crap, with my twins, I pull up one engine.
I certainly agree after having 3 boats with kickers that putting remote controls on, including start is a really good idea. Having to run back, drop the kicker, start it, and then get it in gear and then manage it from the back is no good at all. Oh, well, as long as you are putting in all of the remote stuff and starter etc. why not just get a much smaller big motor and a bigger kicker...like say...twin 50's.
Chuckpacific
New member
I can get on plane with one engine up at 4500 RPM. I'm not sure that's possible with a kicker.
When I was learning to fly single engine, other students wanted to progress to twins quickly as commercial pilots. My instructor calmly pointed out after a few thousand hours as an instructor what his dream plane would be. It was the big Pilatus turbo single. He pointed out as Bob does the inherent challenge of a twin plane to keep airspeed up where it needs to be. My instructor used to say the second engine in a light twin just carried the bird to its ultimate crash site. Boats and planes are different. An engine out in an airplane is potentially an emergency. In the boat we have food, water, bunks, radios, phones etc. it usually is merely an inconvenience not life threatening. We see high time owners like Bob with a single with a press into service dinghy motor Bill and El with twins, lots of folks with singles and kickers. Young Sam is running Retriever to Alaska with a single and kicker. I bet the kicker won't be needed. I run a single no kicker. I don't fish. I think if you have a kicker you had best run it under load at least weekly to be sure it will go for you. I'm not offshore so if the engine goes its a call to a buddy boat or boat Us . I'll nap or have lunch meanwhile. I have been hove to at sea for several days at a time in gales so boats that stop don't automatically scare me We have guys fishing off Bamfield with triples and kicker! Boston Whalers and big Grady's. Some of those have come home on a line too. Bad fuel will kill off all of your engines. Most of the Inuit and Inupiat Alaskans have singles. They boat in harsh areas. So the discussion goes around and around with no best way. Use what's there don't go and repower right off the bat. If new, pick what you want, not what is "best". You could probably fit 4 at 25hp across there or at least 3 at 40. Although now you have weight issues. I like a single for simplicity and I can afford to do whatever is needed on one engine. Might have to cut corners with two. Les makes some good points with his Marinaut thinking on why they are going single. Wow. George :smilep
Just for kicks I looked at the Grady owners forum. Lots of triples there. The guys running triple 350's yamis are asking about prop pitch for best economy! The guys are saying should have gone triple 250's. With the 250's they get "almost" 1mpg. Every boat has issues! With our c dorys, we need little outboards thank god. Single or twin not many triples in c dory land. Enjoy your boats folks! George
We have twins on the tomcat. Just the way the boat is. We like the ability to maneuver in close quarters and I'm still too new to boating to be able to say that I could do the same with a single. But I will say that when it comes time to service the engines the cost adds up. Two lower units to service, two fuel water units, two oil changes, and so on. Money!
I have discovered a new way of time and weather forecasting !!!
Anyone else noticed that if we have a spell of cold wet/gray weather right at the start of what should be a new boating season, we always get the "Celestial Twins" versus "Sad Singles" discussion ???
How about if one of the twins is counter rotating ?? Doesn't that make them non-identical ?? Is this a legal union? Why can't one of them be a different power rating ?
Time to get "out and about" and spend our children's virtual inheritance before we have to worry about our electric powered wheelchairs with built-in porta-potties. (Come to think of it, maybe the composting head could be used as a power source)
M
Anyone else noticed that if we have a spell of cold wet/gray weather right at the start of what should be a new boating season, we always get the "Celestial Twins" versus "Sad Singles" discussion ???
How about if one of the twins is counter rotating ?? Doesn't that make them non-identical ?? Is this a legal union? Why can't one of them be a different power rating ?
Time to get "out and about" and spend our children's virtual inheritance before we have to worry about our electric powered wheelchairs with built-in porta-potties. (Come to think of it, maybe the composting head could be used as a power source)
M