Engine for Hammerhead .12

[Shannon SC]

I have thought about using the Traxxas Pro .15 from my NitroVee in the Hammerhead .12 when I get one in my hands. Problem is that it's not much on RPM but seems pretty good on torque, at least in the hull that it came in. I am continuing to test props, nitro%, tuned pipe, and even the hull to try to get the RPM above 20-22K. Any suggestions or comments are welcome.

I like the water cooled engines and am considering buying a new one for the new rigger. Anyone want to offer any suggestions or comments ?

 

[TimD]

20 -22k? how did you get that figure? If it is correct you are way overpropped or the pipe is all wrong. I don't know what the rod is like in the Traxxas, but if it can't pull 30k it's not going to get along very fast. Small motors need to rev!

 

[waterbug]

Hey,

How does one go about determining R.P.M.???

Is there a tack like for the air planes???? Do you use a mechanical tack???

What's the procedure guy's???

Shannon is the NitroVee a surface drive or a subsurface drive?? If it is subsurface, changing it to surface drive would make it alot faster and rev more.

 

[Ian Inverarity]

waterbug,

You can make an estimate based on tuned pipe length and exhaust timing, but that is not an exact science as particularly tuned pipe length is hard to accurately measure.

I use one of the tachos that Dave Marles sells. Can be a little difficult to incorporate tho, you really need to build the boat with the tacho in mind. But you can adapt one to fit.

Bottom of the page: http://www.prestwich.ndirect.co.uk/fsrv/tr...mtabsfloats.htm

Ian.

 

[waterbug]

Nitro,

Could you attach the magnet to the flex shaft between the stuffing tube and hex flex or what ever engine attachment u use? And will any of these attachments cause a imbalance??

Vibration Kills !!!

 

[Ron Olson]

The Traxxas might work OK as a starter engine. One problem with some of the older models (I don't know about the newer ones) was that they had an open cage bearing in the front that messed with the carb settings letting air in. I myself will be looking for another engine down the road after running my Trinity/Picco/NR. I'm thinking of cutting a few fins off of the heat sink, my feeling is that the engines are running in a cooler environment than if they were inside of a car or truck body. Any other opinions on this?

 

[_laxmasta2039]

shannon,

i wouldnt advise using a watercooled head in a lil' rigger, it is just additional weight and plumbing that you have to worry about leaking. a heat-sink finned car head will be fine as long as you expose it to lots of air.

Ron,

i think it's gonna depend on how your setup is and also how big the fins are, some of those car fins are huge and will just create drag, but i would wait untill you've got it set up and running to make any head adjustments, unless the engine wont fit because of the fins, in which case i'd get out the hacksaw!! lol

Jeez, i noticed the .12 hammer recommended to that guy on rczone asking if a .15 wouold fit in the hammerhead, and it costs 199 green men!

Joe

Joe

 

[waterbug]

IF YOU WON'T TO PLAY YOU GOT TO PAY !!!!!!!

:'(

OR brakeout the Dremel and ggggooo at it!!!!

A 80.00 to 100.00 engine worked right can hang with some of the best out there!!!!

If you are going to spend $199.95 then why

not spend 30 to 50 more and get the record holding engine? The Black Pixie or Black Pixie Outlaw .12 !!!!!

If you buy the O.S..12 tr turbo@ $199.99 why not get the best !!! If you just want to cruise why spend the big $$$$$????

Just my $.02

 

[Ian Inverarity]

Waterbug,

The supplied magnet is in a collet that is held on to a 5mm shaft with a grub screw. The European boats use 5mm solid shafts, so this is fine.

For my boat I glued a magnet into the face of the flywheel and mounted the pickup of the engine mounts. I did balance the flywheel using my prop balancer.

Ian.

 

[EatMyShortsRacing]

Ian,

Anything on your boat you havent balanced??? LOL

EMS Racing

 

[Ian Inverarity]

Craig

The driver is pretty unbalanced! 8)

Is anything on your boats balanced?

Ian.

 

[EatMyShortsRacing]

Ian,

Yes!! My fuel tanks are balanced!!! ;D

Actually I balanced up 2 X665 s for the Seaducer. Plus a few other props... just need to heat treat them all now.

Hey what is this Black Pixie engine BTW??? I spose we better research what is hot etc... 8)

EMS Racing

 

[Shannon SC]

Actually, I am only guessing at 20-22K RPM. Compared to the 1/10 oval cars that I have heard at the local track, I am estimating that it has about 2/3 of the exhaust freq/tone. Those guys told me that they were running at 35+K RPM.

For aircraft , we used to use a Vibratach, problem is that you have to hold it against the head to read it. Not easy to do with a boat in the water.

Thanks for the comments, I had a deep down feeling that a toy boat motor wasn't really a good choice. The Traxxas NitroVee has been good for learning and is a blast to play with. I still want to get the most out of it that I can, 50% nitro wakes it up and I have some props to work with.

I am guessing that I have a couple of months before I need to have the new one in hand. Now to make choices between manufacturers and marine or car, hmmmm!

 

[Eric Perez]

The new Traxxas 2.5 Motor developed 1.33 HP with 20% fuel. I think that is the new benchmark for a small-block .15 . I have to run my .12 with the .21 Hydros at my club, so a .15 would not be considered illegal unless you had a bonafided .12 class. They say that the engine will be available new in the $150-160 range.

 

[waterbug]

Craig,

The Black Pixie is a Rossi 12 with 1.8 hp befor mods. { claimed } The engine is black with silver head.

For $220.00 US!

Nitro,

Do you think i could make a split brass tube bushing and thighten the grub screw down on it to clamp it on the flex shaft just long "'enof"' to get a baseline reading?? That way i could use it on other future boats and not have it permanent to an exstint???

BOY MY SPELLING SUCKS

 

[Hammerhead]

I saw that someplace before. I think it was Don Templeton's post. He said it really only had 1.4 hp before mods.

I would go with the sirio if you are going to get a hot .12. It is cheaper, and you can't go wrong with the AAC sleeve.

(If you don't know what AAC is, It is AluminumAluminumChrome. The typical type is ABC Aluminum Brass and Chrome.

It is not recommended for beginners. If you break them in right. You will never break them. The AAC stuff has supposedly better heat transfer, so everything expands at the same pace. This basically eliminates frozen pistons that will cause other damage to the engine. The only thing is, they are really tight when they are new. I wonder if the sirio has been pre-lapped. I know that Nelson AAC stuff isn't .

Hammer

 

[waterbug]

Hammer,

That's the conclusion I came up with when you and Tom said the O.S.. Even though the OS is good and there is a 7 port sirio sleeve out there, that would make the OS in the $280.00 u.s. range {199.95+79.95 kit} It's hard to beat the Sirio 12 bang for your buck!!! $149.95 1.5 hp {claimed }

DO you think my plan for the OS 21 xm will work ??

 

[Hammerhead]

Sorry Waterbug! No reply on the Q's you asked of me. Do you want me to re write the mail saying that I want to put a VZ sleeve in an XM?

I think that would be an easier question for him to answer. Not many people I know run Outboards. The only kind I have ever owned were K&B. Wouldn't know off the top of my head. I bet a VZ sleeve and piston would fit in an RZ, though. If you have an RZ laying around, try it's sleeve out in your XM.

Hammer

 

[waterbug]

Hammer,

That would be a better question!! The only differance I see in the RZ and VZ is sleeve lenth 28mm vs 32.5 mm and the 4 vs 7 ports and16.7 bore vs 16.4 !! Stock bore being 16mm. Don't k now sleeve lenghth, no one over here seems to want to help!!!

Sorry it took so long to answer, had to digout notes!

 

[topfuel443]

Im not sure what the original question was, but the rz sleeve will fit in the xm engine. heck ive even put the rz engine on my outboard lower end before. much improvement over the xm.

James