Will the right person read this?

[donald branscom]

A 9HP outboard engine is about $1,400.00
A 9HP inboard diesel is about $7,000
A 9 HP air cooled (4 stroke) gas engine is about $500.00

Something is really wrong.
Why won't SOME company make a kit for all of the small boat builders to use in their boats?

Briggs and stratton used to make such a kit.
I am building my own but not everyone has the skills i have.
From what i have read a 2:1 reduction is necessary.

[pipefitter]

Because the economy of a 1400.00 outboard that is self contained is really a bargain and with the advent of the 4 strokes,economical to run. Take a 500.00 briggs and add the running gear and what do you have? Something that probably rivals the cost of the self contained unit. The wooden boat and self build crowd is really a very small market comparatively. Who is going to put all the R&D into such a venture that covers such a small market and then have the profit margin to cover things such as warranty return etc. If there was a market for it,it would be done.Too many viable alternatives and places that are geared to service them internationally.

[donald branscom]

Really:eek:, I always thought marine stuff are expensive to began with..
Yup, I am a scrounger myself when it get too damn expensive to have fun... Shop on e-bay, local ads, or even when someone give it away.. There's always a good usable stuffs lying around..

Now if I could manufactures reliable outboards, I would find a way to cut the cost.. There is no way those new outboards should be that costly..
It almost $800 for Briggs & Stratton's 5HP outboards... It ain't worth it... I can make one cheaper, by attaching 8HP Briggs to a old lower units that have blown engine... But, the noise from air cooled engine is another story..... Huh, I can't hear you....

I just ran a 11HP Robins-Subaru generator the other day and it was VERY quiet. I stood next to it for 10 minutes and it was not a problem. I have been on full size powerboats that required a headset.

I plan on using a 6.5HP Honda with belt drive or chain and 2:1 gear reduction with wet clutch. the engine is 17X17X17 inches.

I have been out in the ocean and had to deal with outboards and i did not like it. I would rather have the engine inside the boat.

By the way...that Briggs and Stratton outboard is NOT designed for saltwater use and the retail price is $745.00 approximately.

[Hesp]

"Why won't SOME company make a kit for all of the small boat builders to use in their boats?".......Donald

Here in the UK Watermota used to make and sell a small petrol inboard with shaft, tube and feathering prop. Is that the kind of thing you mean?

Demand must have been to low because they closed that part of their business down.

http://www.sheridanmarine.com/watermota.shtml

[andrewe]

My set up goes like this: Tecumse 10 hp. ex. defunct garden tractor (gift) puts out 8 hp at 2,600 rpm. The Yamaha outboard leg expects power at 5,000. rpm to reduce it at the gearbox by 13:27 to turn the prop. So I am using a 1:2 gear UP from the engine to the leg by toothed belt. This gives me 8 hp at about 2,500. rpm. at the prop.Not too bad. The only costly bit might be a sail-drive prop for my hull speed of approx. 6knots. As for the noise, this is a sailing boat, if I need the engine I am prepared to put up with it. Even then, if it is really too much, I can go for a Honda OHC replacement which I know will be much quieter.
Andrew

The market is too small for anybody to build kits, too many variables boat to boat.-A

[Jim Ledger]

Regarding the 10 HP diesel, there are a few considerations not being factored in here.

The first is longevity. Admittedly, the initial cost is three or four times that of an outboard but the useful lifespan of the motor will more than equalize this if figured on an annual basis. My 10HP Sabb with fresh water cooling will easily last 20 years and 30 would not be unheard of. Plus, the rebuildability, while still in the boat, cannot be matched or even approached by an outboard or air-cooled diesel.

Second: Power. 10 HP at 1800 RPM with a 2/1 reduction turning a 19" wheel delivers the kind of push needed by a medium sized displacement hull. The outboard would be churning up a froth while providing little push on a similar sized boat.

Third: simplicity and reliability. Change the oil and filter regularly and keep it greased and theres not much else to do. If your batteries are flat the diesel can be hand started.The diesel will still be working in a semi-submerged condition.

Unfortunately, Sabb stopped making them, probably due to a small market and the high cost. However, the occasional second hand one pops up now and again and might be worth a look considering the ease of rebuilding and the availability of parts.
http://i104.photobucket.com/albums/m193/searover1916/P1010047-2.jpg

[Andrew Craig-Bennett]

British Seagull outboard secondhand - say US$150?

I don't know how common they are in the States, of course.

[Oscarvan]

Has anyone used the bottom end of an outboard as a "saildrive" with an electric motor inside?

[Steve Paskey]

Is this what you have in mind? From Glen-L:
https://www.boatdesigns.com/products.asp?dept=474

[Oscarvan]

Yes.....excellent! Thanks.

[andrewe]

Goodbasil, an Italian co. used to build a 10 or 15 hp, I´ve never seen one except at the London show many years ago. More recently a magazine tested one-noisy and expensive. They thought the market would be commercial only. Not sure who made it, but feel it was also Italian.
The Yanmar 1GM comes as an air cooled hand start industrial unit. Much cheaper than the marine version but you still need a g/box and sterngear.
The reason for my set up (above) is the boat is designed with an outboard well,centered at the rear of the cockpit. Fitting a conventional engine would mean a big box at the front (useful) end of the c/pit. The weight is not much different to an outboard of similar power.
Andrew

[Varna]

Donald,
I went through the mental gymnastics of this a few years back and arrived at what the inboard marine diesel folks already know. I looked seriously at the Honda twin to drive a chain or belt shaft. Then I designed in an alternator since the power was there. Then the exhaust needed cooling with water so the little Jabsco pump and plumbing bits went into the crowded space on the 21' dream ship. I reasoned that because I was saving so much money that no reverse gear was fine. Or I could get a rebuilt marine gear box and adapt that. Oops! the price just went up $1000+buy the time that is done properly. Then of course to you have to recon with the gasoline danger in confined space-venting, IG protected devices(marine Alternator etc) and the fact also that diesel gives roughly twice the range of gasoline-maybe an issue, maybe not. The driveline MUST be well done- roller thrust bearing, mounts, pulley/chain sheaves/cogs.belts etc, to live well in corrosive enviro....etc etc...Hmmm maybe a good rebuilt deisel is better. Also I think the coast guard will check very close any home spun gas installation for the venting, labeling, ignition proofing etc for good reason and you owe that to yourself and passenger guests. When taht is all accomplished competently there is no way it will be cheaper when you consider all the hours needed to bring it off. And will you be able to insure the boat in 2008? We tend to think of our home brewed solutions through a 1950's view but it is different now than when I watched my dad do his boats, and he did them well with marinized gas v-8s in power boats.
Is your 19er really large enough to take a inboard install? It appears to be a 2000# or so disp. A big sweep for sculling or an outboard seems best for casual sailing and cruising. But if your heading out the Gate for Hawaii or something the Sabb/Yanmar would be worth the $'s. Forget the Briggs- junk engines OK on the lawn- Honda maybe-but the building hours involved....

Edit to add- Not sure where you plan to sail your boat, but it appears to be a inshore type design. I agree with on not wanting to muck with the outboard in the ocean situation. And north cal, oregon, wash coasts must be considered as lee shore situtions when pondering boating any small vessel. That I assume is your reasoning for wanting the inboard ?. Another factor that lead me full circle back to a real diesel install is that WHEN you would REALLY need that auxilary power is not the time to wondering IF the home made set-up will function well. That is why it is best to invest in the true machinery if your going down that path. But I'm not sure the boat you have is one up to any conditions where an outboard would be a hassle or not perform properly(such as in large swells close in and needing offing) anyway, or you wouldn't want to put yourself in that situation ideally.

Just wondering if all the trouble of the inboard is worth it on your particular vessle. But it is convenient to have for sure.

[donald branscom]

British Seagull outboard secondhand - say US$150?

I don't know how common they are in the States, of course.

The seagull still uses ignition contact/breaker points. They get rusted. In the ocean (not a protected harbor) the engine would get swamped. I like the Seagull in a dingy, in a harbor.

[donald branscom]

Donald,
I went through the mental gymnastics of this a few years back and arrived at what the inboard marine diesel folks already know. I looked seriously at the Honda twin to drive a chain or belt shaft. Then I designed in an alternator since the power was there. Then the exhaust needed cooling with water so the little Jabsco pump and plumbing bits went into the crowded space on the 21' dream ship. I reasoned that because I was saving so much money that no reverse gear was fine. Or I could get a rebuilt marine gear box and adapt that. Oops! the price just went up $1000+buy the time that is done properly. Then of course to you have to recon with the gasoline danger in confined space-venting, IG protected devices(marine Alternator etc) and the fact also that diesel gives roughly twice the range of gasoline-maybe an issue, maybe not. The driveline MUST be well done- roller thrust bearing, mounts, pulley/chain sheaves/cogs.belts etc, to live well in corrosive enviro....etc etc...Hmmm maybe a good rebuilt deisel is better. Also I think the coast guard will check very close any home spun gas installation for the venting, labeling, ignition proofing etc for good reason and you owe that to yourself and passenger guests. When taht is all accomplished competently there is no way it will be cheaper when you consider all the hours needed to bring it off. And will you be able to insure the boat in 2008? We tend to think of our home brewed solutions through a 1950's view but it is different now than when I watched my dad do his boats, and he did them well with marinized gas v-8s in power boats.
Is your 19er really large enough to take a inboard install? It appears to be a 2000# or so disp. A big sweep for sculling or an outboard seems best for casual sailing and cruising. But if your heading out the Gate for Hawaii or something the Sabb/Yanmar would be worth the $'s. Forget the Briggs- junk engines OK on the lawn- Honda maybe-but the building hours involved....

Edit to add- Not sure where you plan to sail your boat, but it appears to be a inshore type design. I agree with on not wanting to muck with the outboard in the ocean situation. And north cal, oregon, wash coasts must be considered as lee shore situtions when pondering boating any small vessel. That I assume is your reasoning for wanting the inboard ?. Another factor that lead me full circle back to a real diesel install is that WHEN you would REALLY need that auxilary power is not the time to wondering IF the home made set-up will function well. That is why it is best to invest in the true machinery if your going down that path. But I'm not sure the boat you have is one up to any conditions where an outboard would be a hassle or not perform properly(such as in large swells close in and needing offing) anyway, or you wouldn't want to put yourself in that situation ideally.

Just wondering if all the trouble of the inboard is worth it on your particular vessle. But it is convenient to have for sure.

I see that we both have simular concerns.
The alternator thing is not a problem. Most alternators and generators are brushless nowdays.
The aircooled small engines have electronic ignition and do not need an alternator.
The reason motorcycle engines won't work is that they are aircooled but when installed in a boat would over heat.

I would NEVER go out in the ocean and be wondering if my stuff will work. NEVER!. I put the stuff together aircraft quality and test it.
As far as bearings,gears etc.,. all machines use them.

As far as gas fumes well think about how many sailboats still have ATOMIC 4"s running gas. And Millions of powerboats.
They have those gas fume sniffer detectors with alarms.
I have one in my house that coat $116.00 smells anything.

The single cylinder diesels do not need to cost $7,000.00
You can buy air cooled 8HP and up, diesels now for $500-$1000

[andrewe]

Well thought out Varna and very valide. I don´t know about you, but, in the past, I have met people who think one is nuts if one builds ones own car, but have no problem in sailing on a home made boat. Logic anybody?
Same with drive train in the boat. As long as finance does´t make you cut corners the result can be as good as store bought.
Andrew

[donald branscom]

Who, praytell, makes a 9hp diesl outboard?

Yamaha. But it is not sold in the USA.
But i did not say outboard diesel. I said inboard diesel.
I went backed and checked my original post. And i did not edit it either.

[Jim Ledger]

Donald, why are you griping about the cost of an engine that isn't suitable for your boat?

[donald branscom]

Because the economy of a 1400.00 outboard that is self contained is really a bargain and with the advent of the 4 strokes,economical to run. Take a 500.00 briggs and add the running gear and what do you have? Something that probably rivals the cost of the self contained unit. The wooden boat and self build crowd is really a very small market comparatively. Who is going to put all the R&D into such a venture that covers such a small market and then have the profit margin to cover things such as warranty return etc. If there was a market for it,it would be done.Too many viable alternatives and places that are geared to service them internationally.

Other countries are VERY interested in small inboard gas engines (8-13HP) for fishing boats. Meanwhile some Americans are using V-8 car engines in a 18 foot boat.

One of the reasons other countries are interested is they want to make less pollution.
Right now some countries use two stroke outboards and diesel outboards that put out a lot of emmisions.

A gas operated Robins-Subaru generator like you see at rental yards
meets tier3 USA emisions standards for 500 hours of use.

The HONDA generators are probably just as good.

[Jim Ledger]

Honda juuuust can't quite get the right SOUND.:D

http://allfishingvideos.blogspot.com/2007/08/sabb-marine-diesel-engine-part-2.html

http://www.youtube.com/watch?v=pQkCDLMHCiQ

[donald branscom]

Yes, I would run a inboard too... since there is many possibles for inboard set-up.. Why, couldn't a person use a lawn and garden equipment engines? As long exhaust is plumb right without contacting any combustable materials..
Ya, know.. If you could find a used small lawn tractor with diesel engine, like John Deere, Kubota, etc, for real cheap deals.. "Imagine getting a 20HP diesel for price of new 9HP diesel"
Getting a engine would be more reasonable that way, than buying a new engine alone.. But, who wants to destroy a useable tractor for the engine?

As for engines from generator, some have tapered shaft..

For that Honda 6.5 HP with a belt drive or chain drive.. Can't you get a drive reduction via it drive drive or chain? Like running a 2" pulley on the engine,(some wet clutch would have a reduction already) and 4" or 6" pulley on the prop shaft, maybe?
Some of them garden roto-tiller engine have a provision for tiller reverse.. It can used as reverse in the boat..
Just suggesting an idea:)

I have read a report by a foriegn goverment that had engineers work on this very project.
They used an 18 ft. boat for thier tests.
10HP gas engine with no gear reduction,10 inch diameter prop,
pitch 7, running at 2000 rpm. Result ok but then....

Then they did a test with same prop ,same pitch ,same boat,but the engine had 2:1 gear reduction and they said it was much better.
These were engineers.
So that is why i would start by having the engine with gear reduction
and fine tune with altering the ratios of the sprockets or a toothed belt system.

I went online to a NISSAN website that had a chart that said 5-6HP engine with small boat would require a 7.7 inch diameter prop,pitch 8, with their 3 blade prop. That is where i plan to start.

6.5 Honda, 2:1 gear reduction-wet clutch included. Quiet and oilless nylon tooth belt drive.

[pipefitter]

In the initial post,it was asked why nobody makes a kit. Surely a self builder can meet or exceed mass produced parts but it helps add credibility to the design when the designer builder is on board. Is kind of like my old ford falcon. The freeze plug gave out and in a pinch,I stuck a clorox bleach bottle top with a rag wrapped around it and loosened the radiator cap and drove that car reliably for 2 years like that. It was good for about 60 continuous miles before needing more water and the temp guage was a good indicator being I knew to keep my eye on it periodically and the only aside to my design was that I kept a couple jugs of water with me as parts for the rig were plentiful.There was an uneasy feeling though when a buddy would ask to use the car.

I think it's great when someone makes a functional alternative for mass produced items. It's interesting and gives ideas for other thoughts that may not even be relative. I have always been adverse to mass production hype and claims but these little 4 stroke outboards are in my opinion,a great step in the right direction and much closer to what has been claimed in the past.

Nothing wrong with diesels. I really like the motors. I would have one for myself. I could also see me designing a rig for a boat of my own just for the hell of it when I have nothing else to do. And I wouldn't have a v-8 in a boat,even when gas was cheap unless it was a 283 chevy. I worked on commercial fishing boats and the best part was the sound of a well tuned Cat running continuously and without issue. If I had an offshore boat,that's what I would have. Back then,in the size boats I worked on,there was a single screw,twins were for larger boats and nowadays,I see folks running twins for redundancy. In the case of the cat diesel,it wasn't really a thought the engine would be what failed.

[donald branscom]

This is a photo of the Briggs & Stratton KIT that used to be sold in the US.
It had 2:1 gear reduction as you can see.
http://i13.tinypic.com/53sed8p.jpg
<a href="http://tinypic.com" target="_blank"><img src="http://i13.tinypic.com/53sed8p.jpg" border="0" alt="Image and video hosting by TinyPic"></a>

[Jim Ledger]

That looks easy to make.

[donald branscom]

Regarding the 10 HP diesel, there are a few considerations not being factored in here.

The first is longevity. Admittedly, the initial cost is three or four times that of an outboard but the useful lifespan of the motor will more than equalize this if figured on an annual basis. My 10HP Sabb with fresh water cooling will easily last 20 years and 30 would not be unheard of. Plus, the rebuildability, while still in the boat, cannot be matched or even approached by an outboard or air-cooled diesel.

Second: Power. 10 HP at 1800 RPM with a 2/1 reduction turning a 19" wheel delivers the kind of push needed by a medium sized displacement hull. The outboard would be churning up a froth while providing little push on a similar sized boat.

Third: simplicity and reliability. Change the oil and filter regularly and keep it greased and theres not much else to do. If your batteries are flat the diesel can be hand started.The diesel will still be working in a semi-submerged condition.

Unfortunately, Sabb stopped making them, probably due to a small market and the high cost. However, the occasional second hand one pops up now and again and might be worth a look considering the ease of rebuilding and the availability of parts.
http://i104.photobucket.com/albums/m193/searover1916/P1010047-2.jpg

JIM ! You keep torturing me with that photo of that beautiful SIMPLE rugged SAAB. Now I go to sleep at night thinking Ponk...ponk......ponk.....ponk ........zzzzzzzzzzz

[pipefitter]

That looks easy to make.

What about the motor set up on those Asian boats with pretty much the same thing but hung on top of the stern. It's really kind of the same thing except stationary. I don't see it as difficult. Kids build go-karts with more complexity from raw materials.

[Jim Ledger]

Ain't she purty? Did you check out the utoob links?:D

Seriously, though, Donald, When you talk about $7000 for a 10 HP inboard, thats what you get, an engine suitable for a small cruising sailboat. And, as such, the price is not so far out of line considering the total cost of such a boat.

[Paul Pless]

oh for the want of the infamous china diesel thread

[Jim Ledger]

Donald, you've got to check this one out.:D


http://www.youtube.com/watch?v=uwJEltD9ehc

[JimConlin]

I've recently bought a 6HP Tohatsu 4-stroke outboard for my new boat. Cost was $1350+. I am very impressed with its quietness. It's going onto an able sailboat, so at 20 hrs./year, it'll probably outlive me. Wat's not to like?

[donald branscom]

Donald, why are you griping about the cost of an engine that isn't suitable for your boat?

Jim,

They make small engines now to fit just about every concievable purpose. I am Griping because i would love to see HONDA or BRIGGS & Stratton offer a kit to small boat builders. Not just for the USA but world wide. i hace read a lot on the internet that indicates to me a need for such a product.

The plans for my boat show an inboard engine as will as outboard engine.

[Jim Ledger]

From what I've seen of your boat, Donald, I think an inboard will really cut down on the available space and the prop drag might affect the sailing qualities.

[donald branscom]

Donald, you've got to check this one out.:D


http://www.youtube.com/watch?v=uwJEltD9ehc

Thanks Jim ! a nice little treat.

[mcdenny]

Kawasaki makes a series of V Twin water cooled gas engines of about 15 to 20 hp. I saw one in a hardware store recently for $1350 including radiator. It would take some doing but that would make a great inboard with a water to water heat exchanger and a toothed belt drive. I haven't figured out the water cooled exhaust or neutral and reverse. Maybe hook it to a jet ski pump?

Water cooling would make it a lot quieter than the air cooled Hondas or Briggs.

Onan uses it in a marine gen set and some high end lawn tractors use it.

[kengrome]

If there was a market for it, it would be done. Markets change (Thank God) and this makes room for new players where there were none before.

Take a look at the boating market today, under the influence of escalating gas prices over the past couple of years. Today you can (from what I hear) buy used gas guzzling power boats for a fraction of what they would have cost just a few years ago. Apparently their owners want more economical boats because the fuel costs are killing them.

This creates an interesting new market for fuel efficient boats ... so maybe cheap inboard engines WOULD be attractive if someone would put together a package that builders could buy and install relatively easily with a minimum of hassle. There are certainly plenty of old inboard designs that specify small engines like this from the likes of Weston Farmer, William Atkin and others.

I'm designing new boats for cheap inboard power too, and I have to create this type of inexpensive drive system if I want them to be used in my boats. Maybe I can come up with a "generic" power kit that anyone can buy and use in their own boats -- after I work out the details for my own boats first of course.

[Pericles]

Narrow boats have been using diesels for years. Here is a website that lists suppliers all over the UK and India and Poland. A few emails will get you started.

http://www.canaljunction.com/boat/engines.htm

http://www.hmiengines.co.uk/isuzuengines/applications/thenewboat.htm

http://www.hmiengines.co.uk/farymann.htm

http://www.hmiengines.co.uk/docs/sole/sole17.htm

Pericles

[Jim Ledger]

Here's some old make n' breaks for sale

http://www.catboats.org/cats4sale/archive/cats142.htm

[Ron Carter]

Have not taken time to read the whole thread but when one factors in the cost of a propeller, shafting, packing glands and shaft logs the outboard again begins to look like a bargain. One problem is even finding traditional designs today without fabricating them your self. That doesn't include the rudder assembly if it is a pure power boat.

[MarkC]

And Farymann will sell you a brand-new, modern(ised) "Sabb-like" - small, single cylinder, diesel, able to be hand-started, with suitable drive-shaft-prop etc. in the USA. www.farymann.de (http://www.farymann.de)


but,

if you want to manufacture and sell a kit for those B&S (like above) they look good.


(Edited to add - B&S own Farymann)

[donald branscom]

And Farymann will sell you a brand-new, modern(ised) "Sabb-like" - small, single cylinder, diesel, able to be hand-started, with suitable drive-shaft-prop etc. in the USA. www.farymann.de (http://www.farymann.de)


but,

if you want to manufacture and sell a kit for those B&S (like above) they look good.


(Edited to add - B&S own Farymann)

Thanks for the link.
I liked what i saw. Their smallest engine is 15 D (?HP)
NO PRICE and dimentions not given. The weight of the 15D is 39.9 kilograms or 87lbs.

I sent them an email to get a price. The shipping from overseas might be high.

[MarkC]

around 7hp.


INDUSTRIAL & MARINE APPLICATION
(EAST COAST)

Farymann America
1000 Grey Street
Evanston, IL 60202
Toll free: 1-800-208-7050

ENTEC WEST
16710, SW 72nd Portland
Oregon 97224
United States of America
Phone: +1 503 6392764
Fax: +1 503 6392764
Email: info@entecwest.com (info@entecwest.com)
Internet: http://www.entecwest.com (http://www.entecwest.com/)

[donald branscom]

Have not taken time to read the whole thread but when one factors in the cost of a propeller, shafting, packing glands and shaft logs the outboard again begins to look like a bargain. One problem is even finding traditional designs today without fabricating them your self. That doesn't include the rudder assembly if it is a pure power boat.

Shafting?
cutlass bearing $26.00, shaft is scrap price. the scrapyards are full of them. Lets say $100. for machining. and packing gland $55.00

Sprocket or toothed belt drive $25.00
Engine $470.00 plus shipping.

[donald branscom]

Just talked to a briggs/lawnmower small engine guy and here was his take on B&S and like engines for the marine environment. He claims that the exhaust port is too close to the valve train with such short muffler/spark arrestor and that salt air and condensation plays hell on the valves. As a portable,possibly, where it can be removed and allowed to cool in a drier environment such as a shed would possibly be ok. Adding a modified exhaust system changes the back pressures and can cause things like overheating and excess carbon build up as well.

That does not make any sense to me.
Exhaust valves are always close to exhaust ports on any engine.
Portable generator exhaust mufflers are about 12 inches in length and
are like a rat maze inside.
This boat i am building is a trailer boat and will not be left out on the ocean.
I would not use a Briggs and Stratton . I will use a Honda engine.
I like the technology and the way they build things.

[donald branscom]

around 7hp.
(clipped)


Thanks for the info MARK.

[pipefitter]

I was looking at the engine in the kit you posted above with the short arrestor. Thats why I deleted the post upon further review. Also he said the pull start recoil thing would require servicing frequently exposed as it is. That was the picture I sent to him.

[donald branscom]

Markets change (Thank God) and this makes room for new players where there were none before.

Take a look at the boating market today, under the influence of escalating gas prices over the past couple of years. Today you can (from what I hear) buy used gas guzzling power boats for a fraction of what they would have cost just a few years ago. Apparently their owners want more economical boats because the fuel costs are killing them.

This creates an interesting new market for fuel efficient boats ... so maybe cheap inboard engines WOULD be attractive if someone would put together a package that builders could buy and install relatively easily with a minimum of hassle. There are certainly plenty of old inboard designs that specify small engines like this from the likes of Weston Farmer, William Atkin and others.

I'm designing new boats for cheap inboard power too, and I have to create this type of inexpensive drive system if I want them to be used in my boats. Maybe I can come up with a "generic" power kit that anyone can buy and use in their own boats -- after I work out the details for my own boats first of course.

Thanks Kengrome,
I will share the information and photos of my installation with all the forum members and maybe some of these vendors will start to sit up and take notice. The propeller shaft part is not really a problem.
But i will use a steel tube with fiberglass cutlass bearing and Off the shelf parts that are easy for anyone to get.
I am going to use a NISSAN propeller because their website makes it easy to select a prop with their charts online. I will post a drawing of what the propeller shaft will be like on the prop end.

[Paul Pless]

Nice engines I would say, but that damn metric system have me confused about kW over HP...1 hp equals ~745 watts

[Dave Hadfield]

You could attack the problem from an entirely different direction altogether, and work on designing a better "well" for an outboard engine.

I haven't seen this done yet. A good well should have a simple way of raising and lowering the motor, closing and opening the power leg opening, ventilating and cooling the engine, and providing safe fuel transfer to the engine.

If successful you've got 1) the "power egg" concept -- great for maintenance, 2) a clean, no drag bottom for when you're under sail, 3) the propellor is where you need it to be when the boat is rocking and rolling, 4) a motor for which it is easy to get parts and maintenance, 5) a motor that's less likely to be stolen than an outboard, 6) a quiet, soundproofed installation, 7) no smells leaking into the cabin.

On the downside, you've got a well, which is a hole in the boat, and you lose cockpit locker space.

But really, only ingenuity is required.

[donald branscom]

1 hp equals ~745 watts

Or the ability to lift 500lbs. 1 foot in one minute.

It is all kind of strange right?

[Craic]

I just found a link to an old brochure from the seventies where two boats, the Drascombe 'Launch' and the 'Driver' both had such simple small aircooled inboarders.

Take a look: http://www.drascombe.nl/download/drascombe_folder.pdf

C.

[donald branscom]

I just found a link to an old brochure from the seventies where two boats, the Drascombe 'Launch' and the 'Driver' both had such simple small aircooled inboarders.

Take a look: http://www.drascombe.nl/download/drascombe_folder.pdf

C.

Thanks for digging that up Craic.
I am starting to think that the reason people just started buying outboards is that the number of people that can build things ,like installing a shaft or motor as dwindled to the point that no one knows how to do ANYTHING anymore.

[kengrome]

Thanks for digging that up Craic.
I am starting to think that the reason people just started buying outboards is that the number of people that can build things ,like installing a shaft or motor as dwindled to the point that no one knows how to do ANYTHING anymore.

The Drascombe uses a Watermota Shrimp reversing controllable pitch prop with an integrated 4:1 gearbox -- so in this respect it is a very simple one-component solution to the problem of gearing and reverse. Unfortunately it is no longer in production, so a much more complicated solution would have to be devised today if inboard power were required.

I suspect that this is why outboards have become the norm since they are a very simple one-component solution just like the Watermota Shrimp was many years ago.

[Peter Malcolm Jardine]

I would never use a briggs engine for anything too tough if I could avoid it... unless it was an old cast iron one. I would look for a Kohler, or an Onan engine... perhaps an engine from a defunct generator.. and as far as outboards go, there are numerous models in two stroke from the fifties and sixties that are indestructible... I have two 3 hp evinrudes (3016) that will never die, and the expensive one was 125 bucks.

[pipefitter]

Thanks for digging that up Craic.
I am starting to think that the reason people just started buying outboards is that the number of people that can build things ,like installing a shaft or motor as dwindled to the point that no one knows how to do ANYTHING anymore.

Maybe out there but down here in gator country they still do. Just take a look at air boats and swamp buggies. Necessity is the mother of invention and being there is a common solution to most propulsion problems nowadays that can be had relatively easily and affordable,it's no wonder most people don't.
Most people with mechanical inclination can do it if they want to. I adapted a big block transmission to fit a small block and built the adapter that couples it to the transfer case. I don't see what you propose as difficult. I was more or less just wondering why and for conversation sake.

[Craic]

Er, I am actually owning a 'Drascombe Driver' with that old 'Watermota Shrimp' system. It is a lovely boat, and the inboarder system still works fine, only I now have a 2002 Kubota 9HP engine in it, with electric starter. An engine that is otherwise destined to drive a generator. Fitting it in was simple, flanging directly to the camshaft PTO which automatically brings a 2:1 revs reduction.
A fast boat too under engine and under sail, as long as the wind direction is not too sharp pointed. Been around Fastnet Rock in it and won the Drascombe class overall of Sail Caledonia Raid in 2005.
Hard to find anything similar today. Except maybe the Swallowboats Raiders, which do have an outboarder well, but also a clever flap to close it. That system does come near to an inboarder, and is even cheaper, because the engine required for such a boat is very light, 2.5 HP suffices fully.
C.

[chergui]

That's what I put in my boat a few years ago. With shipping from the east coast it rang in at $6000 for 7HP though. Great little engine but if only I could have found a small gas inboard I'd have gone with that in a second. Diesels take up more space also, which is a big deal in small boats.

Start your own little company Donald and sell them as kits. I'm sure people would buy them. I would. The only small inboard marine gas engine is the Dolphin, that I know of. So it's not like there's a lot to choose from.

And Farymann will sell you a brand-new, modern(ised) "Sabb-like" - small, single cylinder, diesel, able to be hand-started, with suitable drive-shaft-prop etc. in the USA. www.farymann.de (http://www.farymann.de)


but,

if you want to manufacture and sell a kit for those B&S (like above) they look good.


(Edited to add - B&S own Farymann)

[chergui]

How about this one? http://www.youtube.com/watch?v=7zIM2PeFVkc&mode=related&search=

Does it make anyone else besides me laugh? :)

[Paul G.]

Don,

You get what you pay for, Briggs & Stratton engines are poorly made compared to a real marine diesel or petrol motor. It all comes down to weight. Light weight may be fine on a speedster, but it means usually thin castings and small bearing surfaces on pump engines like the Briggs. Excess heat is a major cause of short life spans in marine engines. Will your Briggs run continuously for a a few days or even a week ???

Another factor is rpm, most single cylinder marine diesels operate at much lower speeds than your briggs, they develop their power at lower speeds and have a great deal more torque. If you are building a daysailor with a motor that may be run for an hour or two in sheltered water, then fine. But if you want ultimate dependability in heavy weather there is only one choice, a heavy marine diesel.

[Paul G.]

If you insist on a petrol solution what we have here is an inboard option (http://jwboatdesigns.co.nz/projects/kane/RK-Houdini-6.jpg) which is an outboard that had been shortened and bolted through the hull. Sort of a homemade saildrive.

Cheap, marine quality, all controls etc at hand and parts are easy to get.

[few3]

When are they going to start making small Wankels again?

[The549]

I know I'll get flamed for this, but what about an engine like if one rigged up a water cooling system to keep it cool? Ditch the gas tank, gear it way down...

http://cgi.ebay.com/ebaymotors/10-HP-Construction-Diesel-Engine-L-V-Series-NEW_W0QQitemZ180158318160QQihZ008QQcategoryZ33615Q QssPageNameZWDVWQQrdZ1QQcmdZViewItem

[The549]

Or something like this: http://www.smallenginesuppliers.com/shop/html/pages/products/kohler_vertical_engines1322.html

Longevity due to air cooling and rusting would seem to be the problems to me...ones that might be remedied at least in part. Why am I wrong? :)

[kengrome]

What about an engine like if one rigged up a water cooling system to keep it cool? Ditch the gas tank, gear it way down...Nothing wrong with the engine, I think the hassle comes in water cooling it. What would be the best way?

An easier way to liquid cool these 10 HP China diesels might be to design an add-on 'radiator' that cools the oil externally ... like an add-on transmission oil cooler for a car.

These engines use a trochoid pump for forced lubrication. Can this type of pump be used to pump the oil through an external oil cooler, or would a separate oil pump be required?

One good thing about cooling the oil externally is that it increases the engine oil capacity for longer life and fewer oil changes. Another is that it may be possible to enclose the engine in a sound deadening box with relatively small ventilation ports without having the engine overheat -- since (presumably) most of the cooling would come from the oil instead of the air.

[moTthediesel]

Why not a water cooled China diesel?

http://www.carrollstream.net/10.0Hp%20WATER-COOLED%20DIESEL%20ENGINE.htm

I've had one of these on my cordwood saw for 20 years. They are powering thousands (millions?) of boats all over Asia. Not bad for $600.

moT

[kengrome]

Why not a water cooled China diesel?The only two reasons I can think of might be their weight and size. They are probably ideal for boats in which weight and internal space are not much of an issue (most of William Atkin's boats fall into this category) ... but for a lightweight boat or a boat in which interior space is at a premium, a smaller and lighter weight engine seems to be in order.

I've had one of these on my cordwood saw for 20 years. They are powering thousands (millions?) of boats all over Asia. Not bad for $600.They certainly are very inexpensive, and the way they are built with all that heavy cast iron, they will last practically forever. This feature alone should be enough for most Americans to consider using them. After all, we want our boats to last forever, so why not the engines?

[Oscarvan]

boats in which weight and internal space are not much of an issue

Not going to argue with the space part, but as far as weight, it's listed at less than 100KG, that's a little over 200lbs, a 9.9 Honda outboard weighs more than half that....pretty close, and closer to the center of the boat=better motion.