Inboard outboard air cooled engine

[wildmaninal]

Re: Inboard outboard air cooled engine

Has a friction drive been brought up already? A snapper riding mower is driven by a friction drive transmission/rear end, if you could adapt that type of transmission to the lower unit then it would give you several speeds along with reverse. I know it would take some adapting to do something like this but I just thought I would throw this idea at ya. A side shaft motor would be idea for a friction drive setup though.

Or an ATV engine with a shaft drive that of coarse has a built in transmission, just half to find one with reverse.

 

[Lone Duck]

Re: Inboard outboard air cooled engine

Sorry to be such a downer but I never saw a flex pipe that lasts very long at air cooled engine temps. also don't think it would be wise to use rubber mounts under engine. your lower end is mounted solid to the hull and you do not want movement between engine and lu. I beleive it will have a bad effect on what ever coupler you decide to use.:redface:

 

[maxum247]

Re: Inboard outboard air cooled engine

Took me awhile but I see what your saying! Will let the engine move around to much. Consider the engine mounted solid! Thanks!

 

[maxum247]

Re: Inboard outboard air cooled engine

Has a friction drive been brought up already? A snapper riding mower is driven by a friction drive transmission/rear end, if you could adapt that type of transmission to the lower unit then it would give you several speeds along with reverse. I know it would take some adapting to do something like this but I just thought I would throw this idea at ya. A side shaft motor would be idea for a friction drive setup though.

Or an ATV engine with a shaft drive that of coarse has a built in transmission, just half to find one with reverse.

Might be something to consider for a future project. Always looking for a project that's a little unusual and not often seen!

 

[maxum247]

Re: Inboard outboard air cooled engine

Ok, just throwing out some more idea's here, because I'm fascinated with this project (like my fast electric R/C boats). On the hose coupling idea, I suggest you try it with the PVC, or ABS, pipe collar over the rubber hose (minus the key in the motor shaft) for rigidity, if the PVC, or ABS breaks, be prepared to row home,,,lol,,, But, if need be in the future, if you can get a short piece of 1 1/4" stainless tubing (not pipe) and do the same thing as I suggested, slit it down the middle, and clamp it over the hose (by the way, use as many hose clamps, as will fit) that won't break! I would also think this design whatever material you decide use, will have a tendency to keep everything inline (to run, or spin, true in a coencentric circle) in fact, I'd suggest to put it all together tight (without the glue) then mark out, & drill out your bolt holes, & mount your motor (temporarily) for best alignment. One final thought on this, in the future, you might need to add round rubber vibration dampers under the motor, I suggest you try it as is first though.

Next, I could be wrong, but I think you'll need to block off the exhaust spout on the drive, if you don't use it, (basically it is a hole in the bottom), and water will come into the boat, and seek it's own level inside, (matching wherever the outside waterline ends up being with weight in the boat). Besides, I like the put, put, of a lawnmower engine thru a long piece of ordinary threaded black pipe out the back of the boat (I believe that's the matching thread on the exhaust port of the motor) standard pipe thread.

MikDee, that would be something wouldn't it? First trip out and I'd have one big livewell with that exhaust port left open! I'm big enough to admit it, you just saved me the embarasment of having that happen, I probably would have never have thought of it!
I thought about the rubber mounts under the engine, been advised it's a bad idea. Lets the engine move to much I guess!
I could go and buy a coupling I guess as has been suggested a couple of times but I think I'll hold off, I'm having to much fun chit chatting about how to do things!
The exhuast well that's another story, if only I could weld! Might be better that I can't!

 

[Lone Duck]

Re: Inboard outboard air cooled engine

Where do the exhaust ports exit the L U ?

 

[maxum247]

Re: Inboard outboard air cooled engine

Where do the exhaust ports exit the L U ?

Straight out the back!

 

[maxum247]

Re: Inboard outboard air cooled engine

Thought it might be fun to let you guys suggest a rudder for the "SHAKER"! Anyone have any idea's what would be a good style? If you can keep it simple as my skills are limited when it comes to wood work.
Here are a few pictures of the hull, there not real good but will give you a general idea of the style of boat! Thanks!

 

[MikDee]

Re: Inboard outboard air cooled engine

No rubber motor mounts it is then. Isn't the exhaust port threaded on the motor? normally they are 1/2" iron pipe size, or 3/4" iron pipe size, a short 4"-6" long galvanized piece of threaded pipe going out (known as a pipe nipple), then a 90 degree elbow (bend) then another nipple to suit, keep piping till you have what you need. I've seen this done on a construction job, to keep the exhaust gases, & noise, from a gas powered welding machine, they piped it right out the window. Would a tiller off the transom work for you? you could use this same material maybe 1/2" galvanized iron pipe, using maybe a bolt on "oar lock assembly" top, & bottom, to slip it through, and use as hinges, with about an 8" X 10" metal plate attached on the bottom for the rudder.

oar lock sockets something like these: http://www.iboats.com/Oarlock_Socke...03583171--list_time.1198899321--view_id.56136

 

[maxum247]

Re: Inboard outboard air cooled engine

It's got a big muffler on it with two bolts holding it on either side of the face of the muffler. My bet is that when removed it will be a pipe thread as you mention if so got her made, if not then I'm in for some work!

 

[MikDee]

Re: Inboard outboard air cooled engine

Here's a rough proposed sketch of my ideas:

 

[Lone Duck]

Re: Inboard outboard air cooled engine

It's got a big muffler on it with two bolts holding it on either side of the face of the muffler. My bet is that when removed it will be a pipe thread as you mention if so got her made, if not then I'm in for some work!

Yup! you got her made, run your pipe however you want and then attach muffler to end. You may have to clean threads in block or even run a pipe tap in it. Mower shops carry all kinds of screw in muffs. face your engine to use shortest exhaust possible. Or build brackets to hold pipeing. We are talking vibration again. For rudder, can you use the same type of removable hinges that they use on stake side farm trucks ? Then just for the hell of it use a joy stick with throttle attached. Set it up in front of where you want to sit. Heh heh!

 

[maxum247]

Re: Inboard outboard air cooled engine

That's a pretty basic and simple way of doing things, I appreciate the time and effort that you put into sketching out the diagram! I've seen that design done before but let me say that it was so long ago that I didn't remember it!
Brings back good memories of a time gone by!
The exhaust is pretty straight forword also. Thought about doing the exhaust that way and probably will but my concern was that it might restrict the air flow a bit too much! But you say you've seen it done before, so I guess if it worked for them it should work for me!

 

[MikDee]

Re: Inboard outboard air cooled engine

Exhaust piping, rough sketch aftermarket screw on muffler optional for the future:

 

[Lone Duck]

Re: Inboard outboard air cooled engine

Oh! I forgot. The exhaust ports. I learned a trick from an older fellow when I was a kid. take some sand paper and sand to bare metal around exhaust ports. spread on a good amount of sealall take some flannel cloth and put over it, more seal all , more cloth, more seal all. yup! you have a water tight seal and cheap. course your wife might miss one of her bed sheets. Patched a fuel tank like this once, 5 years later when I sold it it was still there.

 

[MikDee]

Re: Inboard outboard air cooled engine

That's a pretty basic and simple way of doing things, I appreciate the time and effort that you put into sketching out the diagram! I've seen that design done before but let me say that it was so long ago that I didn't remember it!
Brings back good memories of a time gone by!
The exhaust is pretty straight forword also. Thought about doing the exhaust that way and probably will but my concern was that it might restrict the air flow a bit too much! But you say you've seen it done before, so I guess if it worked for them it should work for me!

Nah, not much restriction, on the jobsite I mentioned they used a 10' piece of black pipe, I think it was 3/4" I.P.S. (iron pipe size) and it was no problem. It lost most of the roar, and had a cool, mellow, puta,, puta,, echo type sound.

 

[maxum247]

Re: Inboard outboard air cooled engine

Oh! I forgot. The exhaust ports. I learned a trick from an older fellow when I was a kid. take some sand paper and sand to bare metal around exhaust ports. spread on a good amount of sealall take some flannel cloth and put over it, more seal all , more cloth, more seal all. yup! you have a water tight seal and cheap. course your wife might miss one of her bed sheets. Patched a fuel tank like this once, 5 years later when I sold it it was still there.

What if I were to 90 the exhaust down and under the engine to the lower unit make the entrance hole larger than the pipe so it wouldn't hit and viberate the lower unit or the snout and let it exhaust over board? Would that be to much restriction on the engine? Sort of look like a square "S" of sorts. I know it would be tight if not impossible, just wondering about back pressure?

 

[MikDee]

Re: Inboard outboard air cooled engine

Are you talking about using the spout? it would help scavenge the exhaust out, once under way. I had thought about that, but you would need to make it sealed watertight, (or water will come in the boat as I said before) and definitely needs to be flexible here!

Also remember this exhaust is gonna be hotter then an I/O exhaust that they use rubber bellows on in the outdrive, because it's air cooled, not water cooled.

I would say block the exhaust spout on the L.U. and keep it simple with an exhaust pipe off the motor to the rear. Remember if you had it going thru the spout, it would have to push the standing water out of the exhaust pipe that is at waterline level at rest, when starting.

 

[maxum247]

Re: Inboard outboard air cooled engine

Too much on my mind, forgetting the simple stuff, Will pick it up again tommorow!

 

[MikDee]

Re: Inboard outboard air cooled engine

Some fresh suggestions, I suggest that your rudder should be a plate, maybe metal, maybe plexiglas, and the size (height anyway) should be determined to be the measurement between the bottom of the prop, and the bottom of the boat, minus enough room to clear so it doesn't hit the bottom of the boat when turning, if you know what I mean. Front to back measurement of the rudder should be equal to that, or could be a bit narrower, I would think. If using pipe for the tiller, I would put a slice lengthwise in the middle of the pipe with a grinder, then slip the proposed rudder (plate) into that, and put a coupla bolts, thru the pipe & rudder, to hold it, or weld it in, sorta "sandwich" it in.