nitro newbie

[laxmasta2039]

hey guys,
after talking w/ propjockey about some stuff on his boat, ive decided to try to stack my 25" XS cat with a nitro engine. i was thinking of either the OS xm .15 or the Traxxas TRX pro .15 [probably the traxxas b/c it cheaper] i've never run nitro before, so im not really sure of everything i'll need. the following is a list of what i think i'll need. please tell me if its wrong or there's something missing:
-engine mount
-after-run oil
-glow plugs
-fuel filter
-fuel tank
-fuel line
-some way to transfer fuel from carton to tank
-flywheel
-exaust system
also, what size is the diameter of a standard .15 engine shaft?
is it 3/16"?? if so, can i use a standard 3/16 coupler and flexshaft setup??
please help me out,
joe

[Ron Olson]

You can go with either or find a used engine from an R/C truck or car. Air-cooled motors work fine in the little boats, they get plenty of air, especially the 'riggers and cats where the motors seem to sit higher in the hulls. Air-cooled is also easier because you don't have to run plumbing to them. You can also swap out the water-cooled head for a heat sink on those motors.

[laxmasta2039]

ok. thanks ron. b.t.w., could you please tell me if the standard .15 shaft diameter is 3/16" ?

joe

[Ron Olson]

Usually the 3/16" flex cables aren't needed until you get to the .21 size engines. Most of the props that you will run are made with the 1/8" holes in them. I'm not saying that you can't use the 3/16", but you don't need it yet. I'll have to find my Octura catalog to see if they make a collet to fit the 5mm shaft with a 3/16" cable.

[laxmasta2039]

please excuse my newbieness, but does that mean i can hook the 1/8" flexshaft i have to a .15 engine and run it without risk of breaking the drive system? [if so, u just saved me the price of a high-quality drive system!!!]

[Ron Olson]

Yup, but the downside is that the smallest Octura made for the 3/16" shaft is a X437/3 prop which is about the most that you would want to run on a good .15 motor. This is in a non-lifting prop of course.

[laxmasta2039]

hhmm... i think you and i are thinking on different frequencies.
what i was trying to ask was would it be o.k. if i used the 1/8" flexshaft setup that i have instead of buying a new [and expensive] 3/16" setup. from what u said about the 3/16" shaft being on the large side [or at least the 3/16" props being too big for the most part] im guessing you mean that a 1/8" shaft would not only be possible but actually preferable for a nitro engine. .... also, from ur comment about "catalogue consulting" [something i do extraordinarily often] to see if octura makes a 3/16 collet for the 5mm shaft, im guessing that the normal .15 engine has a 5mm shaft and i am going to need a 1/8" collet to connect the engine shaft to the 1/8" flexshaft. please correct me if im wrong.
thanks a ton for your help ron, you've corrected my faulty assumptions that would have cost me alot of $$.

joe

[Ron Olson]

Sorry, it's been a looong day for me and my brain is kinda fried from a round trip to the Windy City today. Yes, use the 1/8" flex cable! Save the money and blow it on props instead. Try an X435 by the way.

[laxmasta2039]

sweeeeeeeeet!
i'll take ur advice and get some nice props [x435 included] for my boat instead. this is really great, i thought i would have to completely change my boat, instead all im doing is strengthening up some places and [duh] taking out the elec. and putting in a nitro and tank. thanx for everything ron, this means im gonna have a nice prop selection!![lol]

[laxmasta2039]

hey Ron, one more thing:
i talked to the guys at mecoa engines, and they said the K&B .18
inboard marine uses most standard .15 parts. if i added that extra layer of fiberglass and made sure the boat could handle it, would there be anything wrong with using this engine? it seems like a great bargain, since it looks to be high-quality and comes with a flywheel [i think] and can be bought factory direct for less than 90 bucks.

[Ron Olson]

You could use the K&B .18 but this is kinda pushing the limits of the boat and hardware. I hope that a flywhell does come with it or that they do have one as it looks like the carb would be in the way of a conventional one.
Boy, this site needs a boat chat room so that we can talk easier!

[laxmasta2039]

okay, i think i'll probably go for it, and maybe just stick to some 20% fuel and try not to run the boat for too long. also, that'll give me something to work on with my boat while im waiting for the engine to come. [i'll put a couple layers of fiberglass on and reinforce the sponson tips w/ maybe some balsa stock on the inside instead of foam or something like that.] i see what u mean about the carb being placed funny..... i'll ask the mecoa guy about that.

[Ron Olson]

If any of you people would like to have a chat session some time, there are 2 boating sites that have given permission for us to use anytime that we want to.

[laxmasta2039]

oh. ok. that sounds helpfull for some of those times when u get a good discussion going with several people and u have to keep on clicking the darn refresh button to keep up w/ the post. b.t.w., i got an email from the os service department guy 'cuz i asked him about a collet, and the flywheel [which i dont think will go on the K$B engine, so im hoping i dont HAVE to have it] and the coller together would cost me about 45 bucks!! jeez, and i thought b/c i was able to use the same drive setup that the only things in needed were the engine, a few inexpensive exessories, and the fuel!! oh well, maybe my prop collection will have to wait till get over 1 or 2 props.

joe