GhostCMD6

Gday,

Last summer, I built a container ship from scratch. It just had a small electric motor and it ran fairly nice and smooth. This summer I'd like to build a new boat however I'd like to use an engine this time instead of a motor. What specific items do i need for the engine (from fuel lines to prop shafts) to make this work? Again, i'm not quite sure how everything is put together, but I have a pretty good idea. Also, if anyone has pictures of a COMPLETE engine and drive train system, that would be most helpful. The mechanics of the rudders and such I have down. Thanks!

Ghost.

wave waker

u might need starter equipment either pull starter or belt, glow plug , fuel tank, 2 servo for throttle and steering, flywheel, collet..

GhostCMD6

Thanks wave waker for some basics.

Also, if ANYONE just has any pictures of their drive trains or engine components for the boats, please post them! The more the better.

ryan_t888

If you go nitro, you're gonna need a fast hull design. Not sure what you have planned.

You will need:
-engine
-flywheel and coupler
-flex shaft with prop shaft
-stuffing tube
-drive dog
-lock nut
-a suitable prop
-strut with mounting hardware
- Thrust washer...very important

Sorry no photos, I'm sure if you searched around there are plenty.

If you pick up an outboard engine it makes things very easy and cuts costs to some extent. And if you mate the engine to a Home Built Tunnel you will have the coolest machine around! Outboard Deep Vees are much harder to setup IMO.

Nothing is better than the outstanding appearance of any Outboard Tunnel.
What do you have in mind for hull type?

Ryan

Raylon

Hopefully these will help a little. Tried to include several views.

Sean Bowf

I thought most folks don't use thrust washers any more...they just make sure there is a gap, equal to the width of the flex cable, between the front of the drive dog and the strut...???

Sean

ryan_t888

I always use a thrust washer, I don't want a metal drive dog tearing up my strut. The space is there as the flex cable tends to decrease in size as it is under load. If there were no space it would start to pull on your coupler as it decreases in size.

Ryan

GhostCMD6

Thanks ryan for the parts list, things are starting to come together slowly. Do you know if places like towerhobbies or something similar sells like an engine combo type thing? (where you get all that is needed like the engine, the prop shaft, fuel tanks,.....) that would be ideal. Not sure yet what I have in mind, i won't be building anything till summer anyway (i'm at school now) I was thinking something on a larger scale tho, so it may not necessarily be fast, but it will require a lot of force.

Thanks Zelatio too for the pictures! They were most helpful. On that 2nd and 4th picture, can you describe what tube is what? Also, for anyone, whats the trick for not getting water to come through the prop shaft?

Lastly, do you guys or anyone recommend a certain engine (WITH mounts)?? I really like how Zelatio's setup is.

Ghost.

piper_chuck

My Feedback: (12)

If you're using a square drive cable, a thrust washer is needed because the cable can float in the collet. When the cable is locked securely in the collet, it's very important to make sure there is enough space between the drive dog and strut to handle the shortening of the cable when the boat is running. Since you don't want the strut and drive dog to make contact, a thrust washer has no value.

The reason you don't want the drive dog and strut to make contact is that when this happens, it will pull the front bearing of the engine. If enough force is exerted, it can trash the bearing, AND the front of the crankcase.

ryan_t888

This is a very debatable topic. I do not like running the thrust through the flex cable up to the engine. I don't believe prop thrust exerted on the crank in an axial direction could be any good for it either.

If you leave a space between the drive dog/thrust washer and the strut, the flex cable has lots of room to tighten. ( similar to the photo above )When there is no load on the flex cable it doesn't take much torsional force to tighten the cable up, but as it begins to tighten, force needed increases exponetially. Once the thrust washer comes in contact with the strut there is only so much change in length that can occur.

Regardless of which route is taken, a thrust washer will not damage your boat.

Ryan

Grimracer

For sure you want to use the engine to control the thrust of the prop. The engine has a good size bearing up front and none of the force is placed on the crank pin. The tapered collet places all the force on the inner race of the front bearing…hence to the case through the balls then outer race.

Thrust washers are only necessary (like Chuck stated) when you are using a ferule or square drive setup. Both of those I like to avoid.

Grim

Raylon

Which tube do you mean? The red is the intake line for the carb. The green is the exhaust pressure for teh fuel tank. The clear running from the back to the engine head to out the side is the cooling line. The one with just a little blue showing is the stuffind tube. And in the 4th that one showing clear with black at the end is the antenna.

Grease is put in the tube to prevent any water from coming up, and to lubricate it.

GhostCMD6

Thanks Zelatio! Thats the level of clarification I need with the whole engine thing. Could you, or anyone explain a little bit about stuffind tube?????

ryan_t888

Ahh thanks guys, I get it.

Ryan

Raylon

Sorry that was a typo, the blue tube is a kind of plastic that goes inside of a brass(? Not sure if that is what it's made of) tube. It is called the stuffing tube. It is where the flex shaft, or drive shaft of a boat, goes from the inside to the outside of the boat. The blue is just a liner to provide softer and smother suface for the flex shaft to rub against. It is removable and replaceable, because the metal tube is not. The flex shaft has to be greased up so water does not get in and it is lubricated. Hopefully that helps a little more. Included some more pictures also. The front shows the liner pulled out of the tube. I beleive it is actually made from Teflon? Maybe not though. The second shows where the flex shaft exits teh boat. That white fiberglass there is flexible as to allow the strut height and angle to be adjusted.

GhostCMD6

Zelatio, thanks again for all your help. I really appreciate it! I hope that you are not taking your boat apart just for me!!

This might sound like a really ridiculous question... but what is: a drive dog, and the purpose of a flywheel. Please post after your done laughing.

Sean Bowf

The drive dog is the part that goes on the stub shaft that engages the prop. You can see one here: http://www2.towerhobbies.com/cgi-bin...?&I=LXMNT3&P=7

The flywheel...folks say that it is there to help the engine idle....I gotta believe that on top of that...it helps the engine from coming apart when the boat skips out of the water (keep it from revving too high too fast).

Sean

Grimracer

The flywheel is more for starting the engine then anything else. Having said that it does help stabilize the RPMs and if you have a boat that launches hard a heaver flywheel will help launch the boat. Yea got to remember our little nitro engines have no torque and so that flywheel helps carry what little torque they do make.

Grim