Outboard As A Saildrive

[SuperPiper]

This topic has been discussed before on this forum. But a quick search did not expose the thread.

My pocket cruiser has a fairly deep lazarette. If there is room, I may consider installing the outboard in the lazarette with just the lower unit protruding through the hull. The pull cord, choke, shifter and throttle would be extended through the aft cockpit bulkhead.

Here is where you can help:

Would you recommend rubber isolation between the lower unit and the hull? A diaphragm of sorts, like a pre-engineered saildrive. How severe would the vibration be?

Should the propellor shaft be parallel to the bottom of the hull or perfectly horizontal? I assume that the direction of water flow is parallel to the bottom of the boat (lots of rocker on this little tub).

Can I keep the anti-cavitation plate tight to the bottom or should it stand free below the hull? By how much?

[Buc]

Why bother trying to build a synthetic sail drive? Take a look at the outboard well used in the Henderson 30. It allows you to lift the engine out of the water when not in use, a definite plus.

[Raggi_Thor]

CRO - Contained Retractable Outboard,
http://www.socasailboats.com/CRO_System/body_cro_system.html

[JonathanCole]

Anyone else have any links to systems using hatch covered wells for mounting outboard motors? Seems like a good idea.

[Raggi_Thor]

www.saildrive.se
This company converts Hond 15 HP outboards to inboards with feathering propellers.
Some say it's expensive, but you save alot of weight compared to small diesels.

[Nobody]

Have a look at http://www.radford-yacht.com/dsn022/dsn02201.html. It has the outboard in a hatch. TH Eoutboard is able to pivot and is raised for sailing. Also consider the durabiliity. Most outboards are not designed to be contimously imersed.

Nobody.

[SuperPiper]

Ragnar, I have looked at the Saildrive 280. It is exactly what I want: 4-stroke Honda c/w base and thru-hull drive and all at 50kg. But it is just a little too large to fit in the space available.

I'm not interested in an outboard well.

So, what details should I consider for a poor-man's saildrive?

[Raggi_Thor]

Well, I Think Saildrive 280 uses the same drive as Volvo Penta..
You can try to find one of those and add your own small engine?
Or you can ask the saildrive folks in Sweden if they can use a smaller engine.
They where planning on a 10 (9.9) HP because in Norway we pay a tax per HP when we import engines.
But the folding propeller itself will cost quite alot.

[brian eiland]

....So, what details should I consider for a poor-man's saildrive?

Do you have a friend with a machine shop or such experience? How about making your own belt drive unit similar to PYI unit (http://www.pyiinc.com/?section=drive_leg&sn=1) (expensive from them) or utilize a kevlar belt as I suggest at http://www.runningtideyachts.com/power/

[yokebutt]

Yep, we've got them in stock, Saildrive 280 that is, exclusive dealers for the americas and the pacific rim. Contact us at saildrive280.com or call us at (US) 510-769-0602.

Yoke.

[SuperPiper]

The anti-cavitation plate of the outboard would make a good mounting flange against the bottom of the hull. But there is so much rocker (up to 17 degrees) that the prop would be tilted upward. This would be parallel to the bottom of the boat and possibly tangent to the water flow. But, I am also considering extending the lower unit down an additional couple of inches and keeping the axis of the propellor perfectly horizontal. Or, I could just trim the anti-cavitaion plate away. It would not be required under the hull of the boat.

Are folding propellors available for 5hp outboards?

[floridasailor]

hay man it will work just cut the hole and put a transom fiberglassed in the spot and put it at about a 20 degree angle back and then use the adjustment on the outboard to adjust the tilt use a rubber flap to stop all the splash from getting in the boat but you have to isolate the entire hole from the rest of the boat ive done the exact same thing to an old 25ft mia sloop long time ago either this or just put an engine mount on the back and save you all the work

[MarioCoccon]

Hi: Iam always doing inventions in my boats, I hate diesels always need service dropping diesel in the bilge, stinky, noisly, expensive in service and parts, corroded never end this list. At the same way I hate an outboard in the transom making cavitation, getting smoke into the the boat, people stealing it bl bla. Thats the reason iIam making that idea you have a couple of months ago. Months because Iam tring to finsih my Columbia 39 for selled. The inventions its in my proyect a Newpot 27 1970 that boat cross and imagine of nautical miles see my other postings in rudder problems and a capable boat. The way Iam doing it is like this, I cutted a hole of four inches by 8" in the place was the stuffing box was before. Only for balanced its not a big deal. Then Iam gone to cut the fins of the Mercury four stroke 25hp for maked more little the hole and easy to putted back without the propeller. Then cut a piece of teak 2 by 2 and molded with the hull in the inside of the boat but perfectly in angle on the top. Glassed with fiber glass to the hull including the hole. Before do that put four screws form the outside of the boat to hold the wood its not a big deal its the same work of a thru hull. Under the wood the part that its gone to be touching the hull put 6 screws serving like tread passing the wood from one side to another that you gone to use it for hold the mount plate of the motor. That plate of 2 by 2 its gone to be welded to the motor in a perfect angle no way to get back with 6 holes for attachment. The high of the plate can variety from boat to boat. You need to see from the outside and take the desision you nly need two or less feet of the shaft under the water not to much you dont want to much drag. Before and thats the part I dont know yeat its the seal you can use rubber like tires or somethin similar that old preasure and leaks. Its not matter if you put a good seal to leak because the plate cover everything. With that you have the reliance of a diesel in rought see, eliminate noise and somke if you use and a 4 stroke, the problem with shaft leaks, vibration and all the head pains of an inboard. Good luck I hope we learn people to use the inboards for mooring. And more important the half of money and less or cero maintaince. For the shaft if you covered with barrier coat and then put steel primer for shaft and then bottom paint believe me thats gone to be the same protection that the shaft deserve no worrys about that, barrier coat hold in metals I proved.