Need engine for Inboard drive - DIY?

[mgriffin]

Does anyone like the type of motor that is low RPM, crank start? (Like this: http://www.youtube.com/watch?v=CH912V79W18&feature=related). If not, then you must like the annoying noise of high rpm low CC motor. How could you? these low rpm high cc engines are more efficient and last longer. I am on budget of 300 dollars, and after I build my small boat, I will have 200 dollars left. I need an engine like the one in the video, but a little smaller, about half that size or less for my boat. Enjoy the video!

[mgriffin]

No matter what it takes, I NEED A MOTOR FOR MY BOAT. Even if I have to build it. This is my idea for building it.
The engine consists of a steel box 5.25 inches tall and 2.5 inches wide. The walls are .25 inches thick. Overall the engine is 5.5 inches tall WITH the base and the head cover, which are both 1/8 inches thick. If you are looking at the top of the engine, you will see a 2.5 inch square with a screw in each corner. If you turned it upside down, it would be a 2.5 inch steel square. The cylinder has 1/4 inch thick walls, and a 1 inch bore and a 1.5 inch stroke, overall it is 1.5 inches outer diameter. The CC is 19.3055. The connecting rod length is 2.75 inches. The flywheel has a diameter of 3.5 inches and a shaft hole of 1/2 an inch. The crankshaft/driveshaft has a diameter of 1/2 an inch. the cylinder is connected to the the metal box via a 2 inch metal square 1/4 inch thick with a 1 inch circle cut out of it to allow the connecting rod to pass through. The 2 inch square mentioned before is welded inside of the metal box 2.25 inches from the top after the cylinder is welded to the square. The exhaust port is .5 an inch. The space between the cylinder and the metal box will be filled with water AFTER the it is coated with a rustproofer. The top of the cylinder is level with the top of the metal box, and the head cover covers the water jacket and the head of the cylinder. That is all of the information that I am going to give you because if I told you EVERY single detail, such as the fact I am going to paint it green, then you would get bored and not read all of this. The links: Cylinder:http://www.discountsteel.com/index.cfm/go/main.itemDisplay/itemID/44.htm Piston:http://www.discountsteel.com/index.cfm/go/main.itemDisplay/itemID/113.htm Case:http://www.discountsteel.com/index.cfm/go/main.itemDisplay/itemID/30.htm Head and Base:http://www.discountsteel.com/index.cfm/go/main.itemDisplay/itemID/35.htm
These are the MATERIALS that I am going to use to build it. Please tell me if this motor will work

[mgriffin]

Even if none of you reply I'm going to build it still. It's going to be splash lubrication by the way. You will notice that each link has a part before it, so what is on that link is what I'm going to use for that part.

[hoytedow]

That Lister diesel was pretty nice. Are the Chinese building them?

[mgriffin]

Probably, knowing them...My dad is thinking of buying one for a generator set, a 6 horse http://cgi.ebay.com/Metro-Lister-CS-Clone-Diesel-Engine-6-HP-New-Biodiesel_W0QQitemZ120468519999QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item1c0c7bbc3f&_trksid=p3286.c0.m14

[marshmat]

Hi Michael,

Possible? Maybe. I have only two pieces of advice regarding this particular project:
1) Be careful,
2) Don't get too optimistic about efficiency or longevity.

[mgriffin]

Hahah ok. Thanks!!!!
You have helped me alot!!!

[mgriffin]

Inlet system: High Pressure check valve?
(One that lets fuel in when the piston
sucks on it?) Would that work? The check
valve would let fuel in, then after the piston
is through with it's downward stroke, and the
exhaust port lets air in, and the upward
stroke begins, compression should ignite
it. Would I need a glow plug to start it?

[mgriffin]

Oh yeah, I decided to make the piston out of brass and the case out of galvanized steel. Both of those are cheaper. It's still going to cost 70 dollars though!!! I would estimate it's weight to be around 30 pounds, even if it is 5.5 inches tall and 2.5 inches wide!! Oh yes, I'm going to paint it green :D

[marshmat]

Michael,

Do you have the machine shop equipment and skills necessary to turn these chunks of metal into a working engine?

If you do, then you probably already know just how tedious and complex a job this could be. And you probably also know that a skilled machinist ought to be making enough money to afford a small engine.

If you don't, then you're going to get very frustrated very quickly once you start trying to put things together. Example: Brass has a higher CTE than steel, thus a brass piston in a steel cylinder is likely to experience one of two conditions: if it fits properly when cold, it'll seize when hot; or if it fits when hot, it'll shrink when cold.

[srimes]

It's clear from your questions you do not currently have the skills to build a durable engine. Especially concerning the valve train. I'd suggest buying an engine, and maybe modifying it to suite. Many engines can be detuned to run at a lower RPM with a different cam (and maybe an intake). You might need a larger flywheel too.

[mgriffin]

OK, then I make the piston out of the same material. And "These chunks of metal" only need to be cut, drilled, and welded. Everything is pretty much ready to be drilled, cut, and welded. The biggest drill hole I need to drill is 1/2 an inch. The hardest cut is a 1" circle out of a steel plate. All the rest is straight cuts and easy welds and drill jobs. If it doesn't work as internal combustion, then all I need to do is convert it to Co2. I might have to do a little work, so what? I'm not afraid of work. My dad has a welder, a cordless drill, and a grinder to cut steel with. I don't have to do any precision machining, just drill it, cut it, then weld it together. The exhaust port in the cylinder might need to be smoothed down after it is drilled. How am I going to drill the holes for the crankshaft? Easy. A steady hand. I'm going to practice on some scrap before I start this. Why can't I build an engine with simple tools?

[mgriffin]

How am I going to cut a 1" circle with a grinder?! I'm not! I'm going to use a jigsaw.
I didn't mention the valve train. I'm sorry for the confusion, but I'm going to use a check valve for the "valve train". When the piston sucks on the check valve, fuel is let in. After the cylinder moves down to the exhaust port and sucks air in, then it moves back up and the compression ignites the fuel. If you don't believe that will work, then I'm going to use a glow plug to ignite the fuel during starting. After that, it just uses compression ignition.

[srimes]

I don't want to get in to a pointless argument. I DO think it CAN be done. From your posts I don't think you have the knowledge and skill, but if you're determined to learn it's possible. It would probably take years for you to actually build a working engine. If you do make it I'd love to see pics and read your report.

Sounds like you're describing a bastardized 2-stroke gas engine that will "diesel." That would run poorly if it all as far as I can tell.

How will the piston seal in the bore? What kind of bearings will you use and how will you line them up? What kind of check valve are you going to use? Will it stand up to the pressure and how many cycles is it expected to last? Do you have any idea how to answer these questions?

[Rick Willoughby]

Here is modern music:
http://www.youtube.com/watch?v=zg9-APfZ5Tw
Enjoy.

A little more power than the Lister. Full torque at zero rpm so no crank. Just brilliant. China are ditching the lumbering iron mongery in favour of this stuff. Requires a fraction of the energy to achieve the same result because there is no need to lumber all those heavy castings around the place.

Rick W

[mgriffin]

Either it works or it doesn't work! I understand what you are saying srimes, and I know the precision machining that has to be done to produce a "perfect engine". As for your your questions, I am not going to use ball bearings to help reduce friction or piston rings to seal the piston. An the check valve,this: http://www.inpressure.com/check-valves/6000_Low_Pressure_Check_Valves.html I would estimate this to last 100 million strokes, or 92.59 days at 750 rpm. That is the best I can do without spending thousands of dollars of machine tools like a lathe. Take the spudgun, made of pvc and wrapped in tape. It launches a potato 600 feet. You can make it for 15-20 dollars, or you can spend 200-300 dollars on an airgun that can kill a squirrel. Or you can just spend the 15-20 dollars it takes to make the spudgun, that does the same job. You get the point? I don't want to spend 120 dollars on a 2 horse motor if I can build one that sounds better for $70. To add to that, everyone would be asking, "Where did you get that motor?" and I could say, "I hand built it." I wouldn't try to build a motor if I didn't know crap about them! I can't afford to make a 70 dollar mistake on a 300 dollar budget when I still have to build my boat. Please say yes or no, it will work, or it won't work. I will buy the piston and the cylinder sleeve first, so if I make a mistake it will only cost me 12 dollars instead of a 70 dollar mistake. The steam engine I bought has no ball bearings, and it runs better without piston rings, and it runs at 1000 rpm. It is about half the size of the motor I want to build.

[PAR]

Michael, your still focused on this building your own engine thing . . .

Please by all means, build you motor, so you can learn about balanced reciprocal masses, thrust offsets and the many other things you just don't want to listen to when others mention them.

Failure is the best teacher, go for it dude . . .

[mgriffin]

Listening to that makes me have doubts, but at the beginning of the tread I mention that I might buy one also.
http://cgi.ebay.com/ebaymotors/2-hp-briggs-stratton-go-kart-mini-bike-gas-engine_W0QQcmdZViewItemQQ_trksidZp3286Q2ec0Q2em14QQhashZitem19b5e8efe9QQitemZ110426124265QQptZOtherQ5fVehicleQ5fParts
O.K or I could still make a bastardized 2 stroke diesel out of this and still get credit for building part of it :D.
http://cgi.ebay.com/NEW-TECUMSEH-ENGINE-SHORT-BLOCK-ASSEMBLY-750835A-SBV_W0QQitemZ250309355658QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item3a4799a88a&_trksid=p4634.c0.m14.l1262

[PAR]

Don't avoid the process, we all have gone through it, so will you. Build your engine, spend three times on it compared to a manufactured unit, just to have it "toss a rod" after a couple of hours of operation. Oops, maybe a real pressurized lubrication system and bearings would have been a good idea after all . . . live and learn or get more education and not attempt these primitive efforts, before you know what's required.

[mgriffin]

OK, I get it PAR. Reality has knocked on my door and slapped me in the face. I am just going to get a small 2 stroke off a weed whacker and de-tune it and tweak the fuel inlet and put a larger flywheel on it. I need a reliable engine in case I am going upstream against a strong current, and knowing the average 25cc 2 stroke, well I wouldn't call it too reliable. My dad has a weed whacker, and whenever he starts it, it keeps dying, but SOMETIMES it will keep going. When it dies, I hope it will die again so he'll get tired of it finally and buy a new one and I can have the motor off of that one. The first thing I would do is put a larger flywheel on it so it will keep going instead of keep dying. My dad said it would be O.K if I got a motor off a broken mower or a hedge trimmer, but I'm in the middle of Las Vegas for God's Sake! 80% of people out here don't even have a yard, and if they do it is usually desert or overgrown scrub! And I am pretty much going mad waiting for us to move to a bigger house in a place that actually has trees, wildlife and water so I can build my boat already. I'm sure you don't want to hear of my miseries, but it seems everything is going south lately. Ask Apex, his daughters died in a car accident a few days ago and he can hardly get it together enough to answer one of my PM's...Only thing I can do is pray that things get better soon. The economy still sucks, and Obama isn't really helping, but I'm sure all of you know that, don't even mention this great depression is worse than the last one, which lasted ten years.

[mgriffin]

You know what? My idea for a diesel 2 stroke with "dieseling" ignition is not the first one. Don't believe me? go to this link:
http://en.wikipedia.org/wiki/Bourke_Engine

[mgriffin]

Sorry folks, but I found an inboard. You can say what you want, but I am going to use this for my inboard: http://cgi.ebay.com/ebaymotors/2-hp-briggs-stratton-go-kart-mini-bike-gas-engine_W0QQcmdZViewItemQQ_trksidZp3286Q2ec0Q2em14QQhashZitem19b5e8efe9QQitemZ110426124265QQptZOtherQ5fVehicleQ5fParts

[marshmat]

The single-cylinder B&S are solid, reliable, simple engines that last for decades. Build some good mounts for it, give it plenty of ventilation, and it should serve you well.

[apex1]

Yeah, solid and durable. Not like the toys you found earlier.

[Marco1]

When I was 15 I built a kayak out of a corrugated iron sheet. Flattened it shaped it. riveted and soldered it, covered with Hessian bags painted with oil paint and a brush. Built a rudder with pedals and strings, the seat, yet I bought the paddle.
You build your boat first, then think of the motor.
You could do in reverse. Find a motor and build your boat around it.
Since you live in the good USA your prices for second hand engines are very affordable. I suggest something ex agricultural. A water pump, a generator, anything stationary...and I suggest petrol not diesel, not that I don't favour slow revving diesels like Lister. If you are on a shoestring budget, you can not go past an old stationary petrol engine. Dirt cheap to fix too and so easy.
Try to look for a hit and miss, now those are real fun.

http://www.youtube.com/watch?v=oEHGeg5WYYE

There are several post on you tube about Homemade hit and miss engines,
http://www.youtube.com/watch?v=j7amgDalq4E
http://www.youtube.com/watch?v=9rpgzQlrXIg&NR=1
but unless you have access to some serious turning and foundry equipment, you will have to buy parts and end up paying more for an inferior result. It can be done as an exercise in "mosquito coast syndrome"* but I think that your efforts are deserving of a better cause.
You could always do some odd jobs and keep the cash and buy a decent engine for half the effort.
*From the movie Mosquito Coast.

[TollyWally]

"mosquito coast syndrome"
Splendid book in it's own fashion. Reminds me of a saying of my old man's " Poor men have poor ways."

[apex1]

Since you live in the good USA your prices for second hand engines are very affordable. I suggest something ex agricultural. A water pump, a generator, anything stationary...and I suggest petrol not diesel, not that I don't favour slow revving diesels like Lister. If you are on a shoestring budget, you can not go past an old stationary petrol engine. Dirt cheap to fix too and so easy.


It took us the past ten month to talk Mike out of the crap. Now that he has found a cheap and reliable engine, you pop up and talk him into the crap again. I´m not amused.

Richard

[CDK]

I am on budget of 300 dollars, and after I build my small boat, I will have 200 dollars left.

If you really want to stick to the budget, consider this:

I got my first boat when I was about 7 years old. That was 60 years ago.
It was 14 inches long, all metal. There was a loop of thin copper tube soldered to the stern, both openings below the waterline.
At the turn the tube was bend upwards slightly so you could place a candle under it. The candle made the water boil and the expelled mixture of water and steam propelled the boat.
In fact it was the only mechanism I ever saw that could propel a vehicle without any moving parts at all.

[mgriffin]

Well folks, sorry again...I just now realized that the b&s is not fo sale anymore. NO MATTER! I have found a similar one, for about the same price!
http://www.smallenginewarehouse.com/product.asp?PN=21032-0139&desc=Briggs%20&%20Stratton%20Engine%20%20Weed%20Trimmer%20Engine,%20Four%20Stroke,%2034CC
And how stupid was I when I thought I should wait to buy the b&s on ebay?

[marshmat]

Careful there Michael. That's a 34 cc weed whacker engine- exactly what you said earlier you don't want. These are not the same animal as the 150 to 300 cc Briggs single-cylinder that you found earlier (and that, I think, would be a great engine for your projects- simple, reliable, easy to fix and tweak). Marco's point is well taken; good 1-cylinder engines are all over the place in water pumps, agricultural applications, etc. as well as go-karts and the like, so parts (or complete motors) are cheap and easy to find.

[Marco1]

Marshmat, don't tell me that you don't realize that the briggs and stratton on ebay IS NOT FOR SALE anymore. I CANNOT BUY IT. The bid has ended. Trust me, if I had a choice, I would buy the one on ebay, but life has it's cruel ways.

Life is only as cruel as you let it be. I got 150 hit on ebay US just by typing Briggs & Stratton, let alone numerous other equaly good engines.
Here is one.
http://cgi.ebay.com/BRIGGS-AND-STRATTON-8HP-ENGINE-MULTI-PURPOSE-INDUSTRIAL_W0QQitemZ270474707075QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item3ef98c8083

Honda
http://cgi.ebay.com/honda-13-hp-elc-start-gear-reduced-engine_W0QQitemZ260493210237QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item3ca69af27d

[hoytedow]

mgriffin,
Before I leave this thread forever, I just want to say the people just want to help you and some of them do not say things in a gentle way, ever. They mean you no harm. In fact they are trying to help you steer out of harm's way. So please take what they say in the spirit in which it was offered, not the way your mind's ear may have heard it. Be well and we may talk again on another thread where there will be less "heat of the moment".

[mgriffin]

Goodbye, for awhile anyway...
I am moving soon, and we won't have internet for awhile, so bye until then. When I get internet again, I will probably have my boat built and will be busy boating. Can't wait to build it and use it! This is the last time I will be able to use my computer for about 3-5 months.

[apex1]

Good luck Michael, do´nt forget us!

Richard

[apex1]

And please let me have your e mail adress by PM!

Regards
Richard