TRX 2.5 in a boat

[zakerid]

What would be a good hull for a TRX 2.5 engine? I have one sitting around and want to put together a nitro boat. I have plans for the "Electrified", but I'm not sure if that boat can handle a nitro motor. Any suggestions would be appreciated. Dan

[Chris LaPanse]

Will you watercool it, or leave it aircooled?

[zakerid]

I would like to watercool it, but thats if i can get my hands on a watercooling head.

[Ron Olson]

Traxxas has an updated TRX .15 for boats now using a pull-starter and interchangable shafts with a water-cooled head. The slide carb could be a problem.

[zakerid]

I think I can figure out a way to hook up the throttle. The other thing is that I have an engine with the IPS.

[Chris LaPanse]

If you aircool it, then that limits you to hulls with a really big scoop or an open top. Otherwise, it is basically unlimited (between about 20 & 30")

[zakerid]

I'll get a watercooled head, but still wondering if I cut the shaft will it work for a boat.

[Ron Olson]

Nope. You need all the threads that you can get to mount a spacer, flywheel and flex cable coupler.

[fs454]

Hmm...will the TRX 2.5 watercooled work in the Nitro Hammer with noticeable increase in performance?

[Ron Olson]

I'd like to know that myself. Traxxas has a habit (like other manufacturers haven't done this!) of fudging the HP and RPM numbers. I get RCCA once in a while to keep up on what's happening with the small block motors and if you've noticed, you don't see any outrageous claims in there any more.
(Stepping up on the soapbox) I'm glad to see that RCCA and other mags are doing this. If you want to advertise some hot numbers, tell us how you got them! Air temp, humidity, altitude, what fuel you used, etc. to get those numbers. Either put up or shut up as they say! The same thing with boat speeds. I'm sure a radar gun could be in a R&D budget.(Stepping down)

[BurnZ]

Look half way down this page. :cool:
http://www.traxxas.com/products/nitro/trx25/trx_trx25_engines.htm
You may be able to order the head.
Tower sells this marine engine.(#5208: Engine, Multi-Shaft Marine w/ recoil pull starter) :D

What is the difference in the pro .15 and the 2.5? :confused:

[Ron Olson]

They must think that the 2.5 sounds cooler or bigger than just saying .15 .

[BurnZ]

Would the 2.5 engine be better than the OS .15 CV-M?
(#5208: Engine, Multi-Shaft Marine w/ recoil pull starter $165) vs.(O.S. .15 CV-M Marine $100)
http://www.towerhobbies.com/listings/cat-cat-g.html
Just curious. Never run either engine in a car or boat.

What is better rpm or hp for a boat?

[BurnZ]

Here is a list of interesting engines I've found.

Traxxas TRX Pro .15 w/Pull Start Marine $100
Traxxas TRX 2.5 Multi-Shaft Marine w/ recoil pull starter $165
O.S. .15 CV-MX Marine w/ recoil pull starter $130
CEN NX-16 Marine w/ recoil pull starter $ 85
CEN NX-18 Marine w/ recoil pull starter $ 90

What about Dynamite? Can't find it on a website.
Does Thunder Tiger make a inboard marine?

Would any of these not be as good as the Aquacraft?

[Hydro Junkie]

Actually, both RPM and HP are important. A higher RPM engine gives you a higher possible top end. High top ends are useless without the HP and TORQUE to spin a prop that will let you transfer the high RPM's to the water via said prop. When you buy an engine, it works best to weigh the engine RPM and HP ratings against what you plan to put it in and how you intend to drive it.

[fs454]

Difference between Pro .15 and 2.5?

Well, I think of the Pro .15 as a beginner's engine, not too powerful ...didn't like it much in the original Maxx. The 2.5, which I use now in my T-maxx and soon to be Revo, is very powerful, and, with a THS tuned pipe, is catching up easily to a Hyper .21 8-Port maxx when I race against it.

I think it would be a good engine to stick in a Hammer, but i don't know for sure if it will fit well, it has rear exhaut and a slide carb.

[BurnZ]

If you get the marine version of the 2.5 I think it has a rotary carb. You may be able to get the carb and head and be set zakerid.

[Chris LaPanse]

Also get rid of the air filter-there's not much dust on the water

[zakerid]

so I can't use the enginge with the IPS?

[BurnZ]

What is IPS?

[Chris LaPanse]

Integrated Pilot Shaft (or something like that). It is the combination threaded/smooth driveshaft (coming off the crankshaft)

[zakerid]

so...what do you think chris? Can I use the engine with the ips?

[Watercadet]

The IPS will not work with the stock parts.
Adam

[Chris LaPanse]

I think the IPS is nice for cars, but would only be a pain in the A$$ for boats.

[Ron Olson]

Yes, you can use the IPS setup if the engine comes with the spacer, the type that looks like you could mount an airplane prop on. I use this spacer between my block and flywheel because you're going to need it to mount the flywheel properly.

[water dog]

Difference between Pro .15 and 2.5?

Well, I think of the Pro .15 as a beginner's engine, not too powerful ...didn't like it much in the original Maxx. The 2.5, which I use now in my T-maxx and soon to be Revo, is very powerful, and, with a THS tuned pipe, is catching up easily to a Hyper .21 8-Port maxx when I race against it.

I think it would be a good engine to stick in a Hammer, but i don't know for sure if it will fit well, it has rear exhaut and a slide carb.I have the pro 15 and I ported it and it is no slouch .This thing comes alive when you open up the ports and polish up the sleeve.I put race bearings in mine and it screams .I have put a megatech 16 and a fantom 15 in my truck and I like the pro 15 the best.

[4PlayRacing]

I've build two boats with the Traxxas 2.5 engine. The first was an original 1.5 Nitro Vee. I put in a 2.5 with the marine head and purchased a tuned pipe for it. I could not keep the boat in the water! The speed and torque were more than the boat could handle. Also, I even set it up using the return to shore system, however at some point the composite gear that is mounted on the motor and driven by the RTS electric motor completely disintegrated! There was nothing left but a pile of black chips and a melted blob! The second setup was in a 30" fiberglass hull where I custom built the mounts, etc. This one is air cooled and much easier to manage than the water cooled setup. These engines run at 250+ degrees anyway. You just need to make sure they get enough air going past the head.

[water dog]

Wow !.Sounds cool.I have an old pro 15 sitting around .How much would it be to trade it in for a marine 2.5 to put in my boat?.

[CFRACR]

Here is a list of interesting engines I've found.

Traxxas TRX Pro .15 w/Pull Start Marine $100
Traxxas TRX 2.5 Multi-Shaft Marine w/ recoil pull starter $165
O.S. .15 CV-MX Marine w/ recoil pull starter $130
CEN NX-16 Marine w/ recoil pull starter $ 85
CEN NX-18 Marine w/ recoil pull starter $ 90

What about Dynamite? Can't find it on a website.
Does Thunder Tiger make a inboard marine?

Would any of these not be as good as the Aquacraft?


I HAVE FOUND THE DYNAMITE 15S TO BE A GREAT ENGINE. FAR SUPERIOR TO THE AQUACRAFT. HORIZON HOBBY CARRIES THEM.

[BurnZ]

Hey 4Play. How did you rig up the header and the pipe? Is it exiting the transom or is it angled up and out?

[BurnZ]

Soes anyone make a small marine 4-stroke? Like the OS .26?

[BurnZ]

I just seen in the new Tower Talk, an OS .18 CV-RX. Maybe it won't be too long till a marine version is out.

[BurnZ]

The thing with OS is the price though!
http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXGGP8&P=7

[Hydro Junkie]

The only thing I see keeping it from being used in a boat right now is the length of the output shaft. At only 1/2" from crankcase to shaft tip, it's not long enough to put on both a flywheel and driveshaft coupler. My preferance would be a water cooled head as well. Unless you want the engine to be visible on the water, water cooling is a must for a cowled or hatched boat

[4PlayRacing]

I was able to hook up the 2.5's using stock Traxxas hardware. You need to remove the flywheel from the 2.5, since it comes stock with a Tmaxx flywheel. Replace with a 1.5 flywheel, add your clutch bell and so on. Just take a look at the parts schematic that comes with the Nitro Vee. See which parts you need and which ones you have. It all bolts right up. Very sweet.

As far as the throttle, you need the throttle linkage and post from a Tmaxx. Drill a hole in the aluminum mount plate that the engine sits on and mount the post. On top sits a bellcrank that connects on one side to the throttle arm on the carb, and to the servo on the other side. Works great. If I can dig out some pictures of this, I'll post them. I actually built and sold 2 of these setups, complete with the engine mount plate, RTS....the works.

The 2.5 also has a rear exhaust, so you get an exhaust header from a Tmaxxx which wraps around to what would become the back of the hull. Attach a tuned pipe with a coupling and your ready to go.

If anyone has an interest in a new 2.5 with all the hardware to set it up, including the throttle linkages and header, I have one available. Brand new, never seen fuel. I also have a 30" fiberglass hull that would be perfect for a 2.5 setup. Could make an pretty sweet little boat! Let me know if interested.

[Ron Olson]

Pricy especially from Tower! One of my LHS's has the standard length shaft version for less than that one.

[zakerid]

Do you have any pics of the boat that would work with the 2.5
?

[4PlayRacing]

I can take a few if you are interested.

[4PlayRacing]

Some pictures of the 2.5 assembly I made. This was a drop in solution for anyone wanting to upgrade to a 2.5. The marine cooling head is not installed yet on this one.

[4PlayRacing]

Another view

[zakerid]

what about the boat you mentioned above
?

[Hydro Junkie]

A word of advise, 4Play, loose the air cleaner

[4PlayRacing]

Never used the air cleaner....just came with the motor so I sold it with the motor.

I'll take some pictures of the hull and post....

[4PlayRacing]

This is the hull I've used for a TRX 2.5.

[Hydro Junkie]

Looks Good, though a different color background would make the bottom half easier to see

[Watercadet]

I know of one of those for sale with a OS .46 :O

[zakerid]

i've seen that hull on ebay, but I think it's from china or somewhere over the pond

[Ron Olson]

Hong Kong to be exact. I've heard that he has great service and fast shipping on his boats. There were 2 of them on eBay last night.

[BurnZ]

2.5 marine head.
http://64.4.26.250/cgi-bin/linkrd?_lang=EN&lah=0969eca52453555883b498b9c1e7dd2f&lat=1098816218&hm___action=http%3a%2f%2fwww%2ebuytraxxas%2ecom%2f product_info%2ephp%3fproducts_id%3d2335

[4PlayRacing]

For anyone interested in building a boat around the TRX 2.5, I just put all my stuff up for sale on ebay...take a look....I'll be happy to assist in seting your boat up, if interested.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=5931048025&ssPageName=STRK:MESE:IT

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=5931057580&ssPageName=STRK:MESE:IT