New Trawler Build: Introduction and First Question

[healhustler]

Yanmar had a 27 and a 36 that sometimes could be found in the Caribbean, but neither of them passed emissions here and weren't sold in the US. The few actual reviews from users while we were living in Germany reported reliability but a bit more weight and vibration were compromises. Pricing was high compared to equal HP gassers. There was another thread a couple of weeks ago that spoke about higher HP Oxe diesel outboards being spec'd by the military. It could bring something to the public, but higher HP and the weight to go with it. Here's the link:

http://www.trawlerforum.com/forums/s...rds-29555.html

Here's some spec's on the Yanmar 27 sold on E-bay a couple of years ago.

Specifications

Model = Yanmar D27 Diesel Outboard
Type = Vertical crankshaft, 4 cycle
Cooling = water cooled diesel engine
Maximum output/RPM = 27hp (19.9KW) at 4,500 rpm
Dry weight = 181 pounds
Fuel = Diesel, kerosene + oil, or biodiesel
Bore and stroke = 3 - 70x70mm (808cc)
Combustion system = Direct injection (by unit)
Number of cylinders = 3
Valve Driving = Timing-belt driven/OHC system
Cooling = Direct seawater cooling
Starting = Electric or emergency recoil rope
Steering system = Tiller (bar handle)
Speed control system = Tiller (bar handle)
Tilt up system = Manual with spring assist
Gear reduction ration = 1.846 (both forward and reverse)
Clutch = Dog type, by clutch lever operation
Propeller = 3-blade, spline coupling
Engine lubrication = Forced lubrication pump
Lower unit lubrication = oil bath

[Fish Catcher Jim]

What is the reason in setting the outboards set apart like on a cat or pontoon?
What benefits does this gain over traditional centered?

Thank Jim

[BandB]

Originally Posted by Bruce B

I am curious, are there any diesel outboards available in the US?
I know that they are ubiquitous in the South Pacific but I am not aware of any here in the US.
That would be a very interesting possibility wouldn't it?
Bruce

The weight to hp ratio is the killer.

[sean9c]

Looks like something Phil Bolger would have designed. That's a compliment.

Originally Posted by cardude01

In water test data on GH35.

https://www.facebook.com/greatharbou...99795920068741

[cardude01]

Video of TT35 underway. I think this boat will be a cool cruiser. Those Suzukis are quiet!

https://youtu.be/9Q7oxIbD3MY

[FlyWright]

Miz Trom, you must be overflowing with excitement now that your hull #1 has been floated and tested. Very impressive speed and efficiency numbers so far! I've been getting email updates from GH on its progress. Looking forward to the interior pics as they become available.

Congrats!

[Miz Trom]

Thank you kindly, FlyWright.

[BandB]

I think it's a very cool undertaking and anxious to see you in it and enjoying it. I like some of the Rosborough boats and even their 30' trawler RIB's. But this boat takes it all a stage further, a size bigger. I would hope that this is just the start, that Great Harbour takes outboards on up to larger boats. It makes sense in the same way outboard center console have taken that size range over from inboard SF's.

[SlowGypsy]

Originally Posted by Fish Catcher Jim

What is the reason in setting the outboards set apart like on a cat or pontoon?
What benefits does this gain over traditional centered?

Thank Jim

The further apart, the more manoeuverable, especially at low speeds/docking. Takes the advantage of twins, and enhances it. Imagine the differential thrust you will get, putting one in forward, and the other in reverse.

[Fish Catcher Jim]

Originally Posted by SlowGypsy

The further apart, the more manoeuverable, especially at low speeds/docking. Takes the advantage of twins, and enhances it. Imagine the differential thrust you will get, putting one in forward, and the other in reverse.

Putting one in reverse and one forward can be done as long as you have separate throttle controls.
Now if you had something like the new I dock setup (joystick control) you could turn both engines in opposite directions.

My concern was more along the line of single engine control in heavier current or wind and waves.
Further out tends to hinder control on some boats.

That is why you see the bigger fishing boats with them centered either on the transom or sea drive platform.

I saw the results running one engine and it was impressive and I would like to see the performance in harsher conditions. Saw a guy about take out a bridge pylon in heavy curent with only one engine running.
Set apart engines.

Another concern is the suzkies. Parts can be hard to get and take much time. This is coming from some guys who run them. They really like them other then the parts thing.

Sure do like the TT but then again I am partial to the mirage great Harbours big time.
Jim

[cardude01]

I ran a Suzuki for years and had no trouble getting parts. Either got them from the dealer or off the Internet.

[Fish Catcher Jim]

Originally Posted by cardude01

I ran a Suzuki for years and had no trouble getting parts. Either got them from the dealer or off the Internet.

That's always good!
I was coming from what I have been told by those who are on the road state to state. Tournament and guide.
Time is their issue. Said not all that deal with suzkies had parts available and online ordering is not an option.
Lol they could get mercury parts everywhere and lots had newer evinrude parts on hand.

I really don't know other then that. Never ran a Suzuki other then bike and quad.
Jim

[Art]

I'm impressed with your 35' outboard pleasure cruiser! IMO outboards offer many, many good points. There are also holdbacks/troublesome instances that can occur in certain conditions and under certain circumstances.


All in all I'd say outboard[s] feature bonuses that in many ways outweigh holdbacks of inboards with straight drives or out drives or pods. That is till the conditions and circumstances (alluded to above) that my mind's eye foresees come into play.

I also doubt that outboard power will become very prolific in boats much over 40'.

That said: I believe as best bang for the buck... single screw, straight drive inboard with full keel and full skeg as well as protective cage around propeller - can't be beat. But, in many instances, that power train layout can't begin to compete with your twins screw outboard, shallow draft, lightweight pleasure cruiser as a trailerable, live aboard party boat.

[BandB]

Originally Posted by Art

I also doubt that outboard power will become very prolific in boats much over 40'.

:

I know it's not the same but center consoles have hit the 40'+ range now with very prolific outboards, typically three or four, anywhere from 1000 hp to 2000 hp.

[Art]

Originally Posted by BandB

I know it's not the same but center consoles have hit the 40'+ range now with very prolific outboards, typically three or four, anywhere from 1000 hp to 2000 hp.

That is true. And, outboards have been and could be put onto nearly any size or weight boat as new or replacement power source. However, I don't feel outboards will to a great extent replace inboards in heavy weight pleasure cruiser boats or commercial craft for much above the 40' range

[Miz Trom]

Art, if you are referring to the scenario that in a heavy following sea inboards are more desirable than outboards, then I agree. Been there with both. Planning to avoid that situation as much as possible in the future with this boat. It will be great fun learning about the wind and tides in other parts of the country that are new to us.

Searching through threads now, concerned with taking our beloved dog to the Bahamas and Canada.

[Art]

Originally Posted by Miz Trom

Art, if you are referring to the scenario that in a heavy following sea inboards are more desirable than outboards, then I agree. Been there with both. Planning to avoid that situation as much as possible in the future with this boat. It will be great fun learning about the wind and tides in other parts of the country that are new to us.

Searching through threads now, concerned with taking our beloved dog to the Bahamas and Canada.

Miz - I don't mean to down play the greatness of your design boat. For the stance it holds and what it is intended to accomplish I believe it rates 9.5+ on scale of 1 - 10!

Regarding potential bothersome or maybe even dangerous circumstances with outboards on a fairly large boat... following seas is just one of many.

IMO, outboards have many attractions and detractions on fairly large cabin cruiser boats.

Looking forward to reading of your adventures!

[ssobol]

I think that outboards are under rated on medium sized boats. Yes, inboards or I/Os give you some style points. But you give up a lot of onboard space for that. With O/B you can trade the space that would be used for the I/O or inboard engine for less draft or more space for systems or storage.

The most obvious disadvantage of O/Bs is you usually can't have a full width swim platform or "beach" across the back of your boat. Some boats also carry a dinghy or wave runner on the platform.

With an O/B there is no failure of the system that will sink your boat that in and of itself. The 4 bolt repower is also a plus.

In the SE there are plenty of boats in the 30-50' range that carry O/B engines.

With 2 or more O/Bs you can have joystick control that lets you move your boat in any direction with a single control.

Working on an O/B is also much easier (IMO) than an inboard or I/O from an ergonomics stand point.

[Cliff Meima]

I have been following this build and the Sea Piper build both from the concept to the execution. Both are terrific. I will ask for a Great Harbor visit as soon as it is done.

[BandB]

Adding to the outboard trend, a lot of Center Console builders have added Express models in the 35 to 45' size range and they are selling extremely well. The Cabin leaves a lot to be desired but it's a move upward and if they sell, you know you'll see larger. Up to 1600 hp and 60 mph.