RE POWERING THE BOAT

[alex]

Hi Folks!!!!

after a short research on this website I don't found the answers I am looking for...

I have 2 x 9,9 HP Yamaha's in our Tiki 38 which I consider are awesome motors. I spend less than 3 liters/mile when just motoring  , at a speed of 4,5 kn with one motor or 6 to 7 with both. and much less when motor sailing..

the purchase cost I researched recently was $ 3090 us dollars each, including the newly hydraulic tilting .possibility (so the reseller)

In my cruising style, the downsides of those motors are mainly the combustible they use: gasoline. there are 2 or 3 main problems with  it: quality, price and gasoline motors are much harder to maintain than diesels.

I am seriously considering re power the boat as part of a general refitting, and i am thinking either in buying new ones (mine are made in 1998, so almost 15 years now) or change for one 2 two Nanni inboard diesels, (if one 25 HP, if 2 .. 2x 14 hp or even  2 x 10 hp which run with lower RPM).

I think Nanni diesels are reliable and less noisier and also have a great mileage burning diesel. downside: the cost of upgrading and maybe noisier than the Yamaha's

In my cruising life i spend 90% or more of the time at the anchor and rarely I get into a dock, even for refueling. most of times refueling is made with the dinghy... so one single motor placed in the center, would work as well. I will miss the fine maneuvering that I have in present times though.

I would love to start a serious discussion about the pros and cons about the different options and horse power... I have even considered the diesel electric option, but I think its not for me and not for my budget. after a brief research I think the technology is still too under developed and not energy efficient for the kind of boating I do, which involves many hours of motor sailing sometimes.

I am not happy in having large amounts of gasoline on board as we had on the passage from Tobago to Brazil (gasoline in Tobago cost around 47 US cents a liter, so we got over 600 liters, which resulted in a very good deal as we found out later)

As Luis posted earlier in another discussion, my motors were shacked and really wet from all sides, with all the pressure water coming from the heavy seas. Salt was a real pain not only for the crew, but for the motors. An inboard would be less exposed and with diesels , you don't have the carburetor problems we had to suffer.

there is another consideration to do before taking a decision..its about the maintenance and the cruising noise when motoring. the yamahas are pretty quiet when the seas are fine, but turn really noisy when there is some choppy seas and all the vibration starts... i have mine mounted on silent blocks, but this seems not help too much to stop all the noise.

As you can see now, I have a love-hate relationship with the Yamahas... the worst of it is that I am not happy carrying gasoline on board and all the preventive maintenance they need . will be a Nanni diesel solve all or part of that?

a further question that i am thinking about is that at present the propellers are situated at the very gravity center of the boat. with an inboard diesel (one or two) having a long shaft the propeller/s will act more aft, and i have no idea what the results will be, specially in heavy weather situations where cavitation is more likely to appear...  I don't have that problem in present.

Please when giving advise, take in account our cruising stile. I am not a Purist, and we are not too much into inland motoring ( we plan to cruise some rivers in future though), we are sometimes passage sailors/cruisers, and more often island hoppers... we are on a budget and we like to take advantage from cheap (????) combustible prices. we are also not into excessive carbon footprint, but also not into extreme savings.. we just try to keep a balance. we also have large solar panels and a big wind generator that fill 100% of our energy needs , fridge and freezer included. we just run the 2000 i Honda generator to run power tools, milkshakes and equalize our battery bank (4 x 230 VA/ 6 volt, deep circle golf cart ) once a month or so.

waiting for your input guys....

cheers

[Dave Vinnicombe]

I have two 15hp Yamaha Enduros. They are simple engines and tolerant to bad fuel. They are nearly 10 years old and start easily and have proven to be very reliable. I really like the maneuverability of 2 engines. You never know when your going to need it and when you do, its invaluable. From Durban to NZ I had two 24 litre tanks and two spares so carried just under a 100 litres. We didnt need more.

Dave 

[Demi & Dirk]

Thanks to all for sharing your experiences. Think that we choose 2 off Honda 20 HP in pods, as per plan.

All the best

Dirk

[alex]

It seems that this discussion attracted lots of attention and interest... the reasons are that the type of engines we chose for our boats will determine the future quality of our travels.... but I would like to go further and see if I can let personal experiences and passions , to make a serious research based in previous experiences from Wharram boat owner specially those heavier ones over 30 ft long that are able to chose either and outboard or an inboard or even go electric.

I repeat here that there is a big difference between extensive world cruising/sailing , coastal cruising in the US, day sailing or weekend cruising. In my case I want a reliable motor that drives the boat around the world with a balanced ratio between investment and performance / maintenance and so on... In the ideal situation I would make a comparison spreadsheet to take a more scientific decision...

As a first approach I tend to take Mr. J.Wharram experience as the most valuable one, by experience and by specific knowledge. We all know that James is a purist, which I am not, and I think  there are other options that proved to work fine , maybe even more adapted to present 'world' conditions. 

In my personal experience so far , I had no one problems with the motors along Canada, the east coast from the States and the caribbean, but soon as I went out from that area where all the system is adapted to serve/service all kind of motor yachts, things turned very bad:

1. I must make a "mea culpa" due the lack of specific experience.. we went out against the trade winds and swell for 19 days with untied motors which were banging each time a big wave hit the boat.

2. the pods where the motors are attached are too exposed to the seas, water came in to the motors, and salt was covering all the interior, specially next to the spark plugs.

3. we had water inlets in out system , I think through the vents on the tank caps (a covered them with plastic bags and rubber bands and the problem seem to be solved)

4. oil exchange is a complicated task without make any spill... i hate to spill even a drop...

5. we tried different type of propellers and seems to have a big effect on the performance.

6. the Yamaha's will perform poorly or even not work with low quality gasoline, even if you buy the high octane option. this is specially remarkable in Brazil where the alcohol content is more than 25% and there is a poor or no control of the gasoline made by authorities, i have a sample on the boat with 2 liquids that separate in the bottle same color but different density- I never saw that before-. On the other hand diesel seems to have a more uniform quality in 3rd world countries...

7. The motors were absolutely flooded while sailing offshore in bad conditions, many of the internal electrical connector are subjected to galvanic corrosion due the electricity running on them. I can take a pictures of the starter  that was replaced just one year before. we changed some electrical stuff that induces the spark on the spinning wheel, due corrosion as well. All this electrical corrosion was because galvanic electricity. I changed brand new first quality connectors , soldered proper way and protected the best way i could (painted with liquid electrical rubber and then covered with thick electrical grease), only after 2 days of intense salt water spaying. I need to relocate all the batteries to a dry and safe place. same problems with the outboard engines.. 

7. despite what i wrote above , what we saw outside the States, Bahamas and the European colonies from the caribbean, is that Yamaha is the absolute market leader and almost all are 2 stroke motors (noisy and smokey though) , not the 4 stroke ones ... Those air cooled noisy and very cheap mower motors with a shaft are very popular with the fishermen community as well, and Honda seems to lead that specific market...

Cruising around the world has specific challenges regarding our today's topic of what type of motor you chose and is very different as the experience we will get in developed areas....

QUESTIONS

 Dave: whats your ready to cruise boat weight? and the mileage of the Enduros? are they noisy? what about vibrations? where are they situated?

Charlie: what brand  and type of diesels do you have? you bought them new? what kind of service they have/had? and what kind of exhaust system they have?. seems that a proper exhaust system is critical in diesel engines to avoid over heating...

Dirk: whats your research till now? you considered that the motors will be likely flooded when motor sailing in blue rough waters? how you plan to protect them? where will be your cruising areas?

[Demi & Dirk]

Hi Alex,

we are also no purists and want to have a minimun of comfort. Primarily we where looking for a Tiki 38 and so we visited some. One we visited in Cuba, named TouchWood. They had 2 off Nanni Diesel in fixed pods with a long tiltable shaft. They sailed from the Med over the Atlantic to Cuba and had no problems so far. See fotos at the end of my reply. On a Tiki 38 I think, there is not enough space to fit inboard diesel in the hulls. On the other side the pods on a 38 are a little bit exposed, on a 46 the pods are more backward and so (hopefully) not so exposed. Driving systems on a Wharram are always a compromise. The big advantage of a diesel engine are the generators with 70A for loading the batteries and the production of hot water for shower. We where also thinking about sonic legs, but for now we plan Honda outboards and will see what happens in the next years on the engine-market...... 

We are planning a building time of appr. 5 years, then we want to sail 1 or 2 saisons in the Med and then arround the world. But it is a long time till then, so we will see what happens..........

Dirk

[alex]

I copied this information from the german site of Touch wood, a Tiki 38 heavy cruising load (about 5 tons in total )

2 x Nanni Diesel and 14PS

cruising Speed 5 – 5,5 Kn at 2300 U/min with 2 engines

Speed under 1 engine 5 Kn at 2800 U/min

Mileage 1,8 Liter / h per Motor at 2300 U/min

Comment: this is almost half consumption of my Yamaha's ( 3 liters an our each )

[Dave Vinnicombe]

Hi Alex

I have found the T38 and easy boat to sail so my motors are primarily for getting in and out of anchorages.

Dragon's cruise weight is about 4.5tons.

I only motored when becalmed and would run one motor at a time giving me about 3 knots, a 24 litre tank would give me about 10 hours and by then the wind was usually back. I hate motoring and would rather sail at 2 kts than motor at 3! The real pain in the a... when motoring for me is that it usually happened at nite and I would have to hand steer as the solar panels werent charging the batteries for the autopilot (I hadnt wired up the charging coil from the motors and that was a mistake). And that is a very good reason to simply enjoy the peace and quiet of a calm nite - rather than motoring and hand steering!!

Two strokes are noisy and is one of the reasons I dont like motoring.

The vibration is not bad.

The motors are placed per the plans in pods between the hulls.

I was surprised that the cowlings of the motors sealed so well as we had a very bumpy upwind trip from Brazil to Grenada and the motors were wet all the time. No water got in thru the cowlings tho.

The simplicity of this set up and its efficiency for what I need it to do makes it ideal for me. Plus it seems to me to be the lightest option and most cost effective.

Cheers,

Dave

[Marc Tipper]

I have a 46 foot ORO built in 1993 which has a 30hp Lombardini Diesel motor mid mounted in an engine box which hangs between beams 2 and 3. At the rear of the engine box is a hinge bracket with a bearing tube to take the shaft. The power is transmitted from the rear of the transmission to the shaft via a PTO shaft and universal joint. The Shaft is 12 feet long and of 2 inch diameter tube. the forward end of the shaft has a solid shaft section welded to the tube. this solid shaft takes the bearings (same as a car stub axle). The rear of the shaft also has a solid section which goes through a water cooled bearing on the thrust plate. The 17 inch dia prop is then fitted at the end. The thrust plate has a bearing tube below it which holds a melamine wet bearing. the thrust plate has 2 stainless cables connected to the rear corners of the thrust plate which attach to the 4th beam near the hulls, this prevents lateral movement. There is a riser tube which comes off the top of the thrust plate and rises to deck level. There is a small u shaped notch in the rear ramp which holds the riser tube in the down position. the shaft is raised by hand and a spring shackle clip attaches to the riser about 18 inches above the thrust plate to keep the prop out of the water when not in use.

The lombardini propels the ORO through the water at 5 knots at 1950 rpm and uses 2.1 litres of diesel per hour to achieve this.

 

[alex]

Hello Marc

I am very grateful that so many members took part of this discussion, it will help me very much and others to decide in future the way they want to go. Your system looks different and I would love that you add some technical information and pictures explaining the entire installation.

1950 rev looks great and low noise emission.

QUESTIONS

1.  weight of the Lombardini motor. ( included the cocoon if there is one)

2. weight of your boat under real cruising conditions.(to find out the horsepower to consumption rate)

3. if you service the motor since new.

4. noise under way.

5 maximal speed at max rev.

6. vibrations... please describe the type of mounting and levels of noise.

7.cruising areas and the type of motoring you make.

8. type of battery charger. and if there are other machines attached to the motor. like air compressor)

9 reliability and satisfaction level (or if you would make some changes if you buy new)

10. maneuverability in tight spaces. forward , backward and turns.

11. hours meter in the motor and since when you have it.

thank you!!

cheers

alex

[reg]

Hope you don't mind if I put in an oddball suggestion, but I keep thinking about the issues of dink storage, dink power and boat power. 

Why not combine all 3 by making a dink that could be fixed under the beams much like a pod for a central engine configuration, obviously the mountings would need some thought but it isn't rocket science.

This would also help in the maintenance side as well i.e easy to bring the engine ashore.

There are obviously issues with this, but as this thread has highlighted, there are issues with any installation.

[alex]

sorry for my ignorance... but would you describe better what is your idea about the 3 combined dink storage/power ??

[reg]

I don't have any details as I don't even have a boat at the moment.

But I was thinking along the lines of a dink that would clip under the beams and the motor would be positioned so that it could also power the main boat.

Think of an enlarged engine pod that some Wharrams use when powered with a single inboard diesel.

This would need careful design with regard to the height of the prop and the the hull/pod clearance.

Also if you want to use the engine for charging electrics then a waterproof plug and socket would be required.

For the docking side of things, some sort of guide rail for the front end to follow under the boat, with some sort of clamp to fix the back end.

All hypothetical of course, and how this would work in any sort of sea I don't know.

[alex]

Ok , I understood now...

One hypothesis I am working with is re powering the boat with a single  ( and parallel Hybrid perhaps???)  Nanni diesel engine ,30 HP or even 40 hp since they have almost same weight, so I am figuring out the kind of "machine room"  it will need to fit in it.  I would lose the redundancy of 2 machines, and the easy service of the removable outboards... on the other hand I would solve some other problems that brought me to start this discussion: i don't like to have large amounts of gasoline on board, and the diesels have better mileage, specially important in long motoring times (tank capacity) and the other issues I wrote at the beginning of this discussion.

a single engine would force me to redesign the whole deck and cockpit , that I am rebuilding anyway to fit our cruising lifestyle.

another solution, maybe more common sense would be to sell the boat like it is and start to build a 46'er... I am very tempted to do so, specially after looking the great Youtube videos of the ARIKI building  posted by Boatsmith .. but this is another topic.. :-)