ranger58sb
Guru
Aside from the couch things, which sounds like it an issue in both configurations...
I'd have thought all that outboard work on the twins version would mean all-round engine access on the single is better...
-Chris
Mainship 40 general and 1 or 2 engines
- Thread starter charlesr
- Start date
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Aside from the couch things, which sounds like it an issue in both configurations...
I'd have thought all that outboard work on the twins version would mean all-round engine access on the single is better...
-Chris
Dougcole
Guru
I don't think I did a good job of explaining the layout.
There are three hatches in the main salon floor. A big one in the center and two much narrower hatches on each side of it. If you open the single large hatch in the center with twins you step down in between the engines, there is lots of space there. If you open the center hatch with a single, the engine is directly below you, and I don't think (I could be wrong) you can slide in around it without lifting the side hatches. The port side hatch is under the couch (or chairs in some boats).
I seldom open the side hatches, I just go through the main hatch and climb around either forward or aft of the engines. There is room to sit in front of either engine, and decent space behind them, though the shafts/trannys are in the way.
As far as the speed thing goes, as I said in my first post I don't want to rehash the old single vs. twins argument in general. But a 20 to 30 knot boat is an entirely different animal than a 15 knot boat. They come with different issues costs etc.
Coming from our old Gulfstar, we wanted a boat that could comfortably run at least 15 knots when needed. I wasn't remotely interested in sea rays or other Euro styled type boats. We looked at a few sportfish, but didn't like the layouts. I like to fish, but that is not the primary purpose of this boat.
The Mainship 400 with twins checked all of our boxes. Quite simply, the single did not.
Other than slightly higher costs I see no disadvantage in having a boat that is capable of running economically at 7 to 8 knots when desired but can also run close to twice that speed when needed.
Again, I'm not speaking of every boat. But in the Mainship 400, the twin is a better boat, there really isn't a logical argument otherwise.
There are three hatches in the main salon floor. A big one in the center and two much narrower hatches on each side of it. If you open the single large hatch in the center with twins you step down in between the engines, there is lots of space there. If you open the center hatch with a single, the engine is directly below you, and I don't think (I could be wrong) you can slide in around it without lifting the side hatches. The port side hatch is under the couch (or chairs in some boats).
I seldom open the side hatches, I just go through the main hatch and climb around either forward or aft of the engines. There is room to sit in front of either engine, and decent space behind them, though the shafts/trannys are in the way.
As far as the speed thing goes, as I said in my first post I don't want to rehash the old single vs. twins argument in general. But a 20 to 30 knot boat is an entirely different animal than a 15 knot boat. They come with different issues costs etc.
Coming from our old Gulfstar, we wanted a boat that could comfortably run at least 15 knots when needed. I wasn't remotely interested in sea rays or other Euro styled type boats. We looked at a few sportfish, but didn't like the layouts. I like to fish, but that is not the primary purpose of this boat.
The Mainship 400 with twins checked all of our boxes. Quite simply, the single did not.
Other than slightly higher costs I see no disadvantage in having a boat that is capable of running economically at 7 to 8 knots when desired but can also run close to twice that speed when needed.
Again, I'm not speaking of every boat. But in the Mainship 400, the twin is a better boat, there really isn't a logical argument otherwise.
Last edited:
ranger58sb
Guru
Mainship400
Veteran Member
I had the single engine 400T (just sold it). We opened the large center hatch and the starboard hatch to access the engine. You could get to the port side with a little bilge yoga. My next boat will probably have twin engines for all the reasons that Doug stated.
IntoTheBlue
Senior Member
- Joined
- Jan 10, 2016
- Messages
- 151
- Location
- USA
- Vessel Name
- Into The Blue
- Vessel Make
- Mainship Pilot 43
Mainship Twin / Single -Speed
We just met a couple in Yarmouth who traveled 5,000 miles on their Mainship 43 Aftcabin. The boat had twin Cummins 330 and cruised at about 12 knots, capable of 16 knot speeds. I have the same hull, pilot version and run cruising speeds of 15-16 knots, capable of 22 knots with twin Yanmar 440's. I bring this up because if your going with twins, but still want to cruise at 10 knots, make sure that the twins are lower HP engines. Diesels need to run at 75-80 % power at cruising speeds. Running all the time at 50 % is not good for the motors, especially if they have have turbos. (Always heard this, but had it confirmed at Mack Borings diesel 2 day seminar). So you have to power your boat accordingly or if buying used, make sure that the power meets your desired cruising speeds.
We just met a couple in Yarmouth who traveled 5,000 miles on their Mainship 43 Aftcabin. The boat had twin Cummins 330 and cruised at about 12 knots, capable of 16 knot speeds. I have the same hull, pilot version and run cruising speeds of 15-16 knots, capable of 22 knots with twin Yanmar 440's. I bring this up because if your going with twins, but still want to cruise at 10 knots, make sure that the twins are lower HP engines. Diesels need to run at 75-80 % power at cruising speeds. Running all the time at 50 % is not good for the motors, especially if they have have turbos. (Always heard this, but had it confirmed at Mack Borings diesel 2 day seminar). So you have to power your boat accordingly or if buying used, make sure that the power meets your desired cruising speeds.
"Diesels need to run at 75-80 % power at cruising speeds. Running all the time at 50 % is not good for the motors, especially if they have have turbos. (Always heard this, but had it confirmed at Mack Borings diesel 2 day seminar"
As long as the boat is propped correctly running most any turbo diesel at 50% will be fine and even preferred.
As long as the boat is propped correctly running most any turbo diesel at 50% will be fine and even preferred.
IntoTheBlue
Senior Member
- Joined
- Jan 10, 2016
- Messages
- 151
- Location
- USA
- Vessel Name
- Into The Blue
- Vessel Make
- Mainship Pilot 43
Like I said, I've heard it, read it and when attending a 2 day seminar at Mac Boring had it confirmed by Larry Berlin. To say it may be OK to run at 50% maybe one thing. To say it is preferred is against all accepted criteria regarding diesel cruising speed. I don't agree with smitty447. Maybe the 50% theory works with gas motors.
"To say it is preferred is against all accepted criteria regarding diesel cruising speed. I don't agree with smitty447."
If you would really like some good feedback go to boatdiesel(dot)com and ask this same question.
Or you can go to Tony Athens site or call him up and ask his real world experiences with engines of this type at sbmar(dot)com.
Or just go to the sbmar site and read "Tony's tips" for some good background.
Its been 25+ years that I have run similar sized 6 cyl 4stroke diesels with plenty of feedback from similar owners with all good results.
Cruised long Island waters for many years now likely have been out there on the water with you at some point.
If you would really like some good feedback go to boatdiesel(dot)com and ask this same question.
Or you can go to Tony Athens site or call him up and ask his real world experiences with engines of this type at sbmar(dot)com.
Or just go to the sbmar site and read "Tony's tips" for some good background.
Its been 25+ years that I have run similar sized 6 cyl 4stroke diesels with plenty of feedback from similar owners with all good results.
Cruised long Island waters for many years now likely have been out there on the water with you at some point.
I have a twin engine 34 mainship trawler. and I'm so glad I got a twin.
Three times in the last 2 years I needed the extra motor to get back home.
due to 1)crap trap line, 2)impeller down, 3)raw water line broke.
I really don't understand the single engine argument... to me it's a no brainer.
Three times in the last 2 years I needed the extra motor to get back home.
due to 1)crap trap line, 2)impeller down, 3)raw water line broke.
I really don't understand the single engine argument... to me it's a no brainer.
Mainship400
Veteran Member
Jann, curious about how good the engine access is in the 34 twin? The single looks pretty tight to me. Can you get at both the water pumps? All the Zincs?
Thanks
John
