anyone run the Fantom FR21?

[CorradoPsi]

just curious if anyone is running one of fantoms big blocks. i have thier FR15 in my super nitro and couldnt be happier with it. 3 gallons and going very strong. its a powerful mill that winds out plenty far (42500rpm). I'm want to know if their larger motors perform as well as thier small ones. if so they are a heck of a deal at just under $200 at stormer hobbies.

 

[Gixer Jay]

From what a few guys I run with they say its a good motor.. Good power and tourqe.. The only thing they don't think is right are the break in procedures that Fantom recommends for the motor..

 

[WA2FAST]

Yeah, but a motor is a motor is a motor... can't you just use your own tried and true break in procedure? I would assume that you can use a proven break in procedure on whatever motor you want. What breakin procedure to you use J?

 

[CJ-FOREVER]

yeah but at the same price they have fr27. ($200) I wonder how that one will work. Would it actually move the my Mammoth?

 

[CorradoPsi]

From what a few guys I run with they say its a good motor.. Good power and tourqe.. The only thing they don't think is right are the break in procedures that Fantom recommends for the motor..

i agree the breakin in strange, however i used thier method on my FR15 and even after 3 gallons its a very fast motor, with a whole lot of compression. I'm told the breakin is different due to a high silicon content in the piston. they want it heated up so that the silicon conforms to the sleeve instead of wearing off the surface of the piston.

 

[WA2FAST]

Well, I don't know what their break in procedure is, but if it's coming from the manufacturer, I would probibly follow it... they have their reasons, they aren't making it up if you know what I mean.

 

[CorradoPsi]

yeah but at the same price they have fr27. ($200) I wonder how that one will work. Would it actually move the my Mammoth?

well its rated at 2.83hp and 42000 some rpm. id say it would get moving. however thats a .27 no legal for some racing. the .21 is rated at 2.58hp and about the same rpm.

 

[uDi_MP7.5]

And you are just a little drunk if you take manufacturers spec claims and actually make something of them....

Those specs mean nothing in the real world.

 

[CorradoPsi]

And you are just a little drunk if you take manufacturers spec claims and actually make something of them....

Those specs mean nothing in the real world.

i dont care what you think. and no I'm not drunk little boy. keep your attitude to yourself. those specs are there for reference, they arent intended to tell the entire story of how a motor performs. however ill take a motor rated at 2.5hp over a motor rated at 1.5hp anyday.

 

[uDi_MP7.5]

Thanks for re-iterating my point in the process of insulting me.

-uDi
:fro:

 

[CorradoPsi]

Thanks for re-iterating my point in the process of insulting me.

-uDi
:fro:

then why didnt you state what i did, in your first post. instead of a smug comment about my perceived drinking habits and a close minded statement about numbers meaning nothing. there is no need for that. you could have simply stated that numbers dont tell the whole story. they do however tell part of it.

 

[uDi_MP7.5]

Okay i'm sorry. It's a figure of speech, not an implication of your 'perceived drinking habits'. I was just stating what you said was incorrect, albeit in a creative way.

Engine ratings are only good to compare between engines from the same manufacturer - and for companies like ofna or fantom, where the figures seem to be reasonably unrealistic, and in my opinion have little basis - they may not even be valid enough to do that.

Your comments along the lines of "i'd say it'd get it moving" appeared to be based on the spec claims in that very same post, and what I was trying to say was, that those figures are no way to judge. Obviously most reasonable engines these days make plenty of power, but when it comes to how much and which is better than the other, some figures on paper will do zero justice compared to speaking to someone who has run them, or far better, seeing them in action yourself.

So for any engine, it's best to simply ask if anyone has used it, and if no one has, it's generally best to wait till they have - so you can get feedback on how it compares to other engines in real life.

Oh - and just so I haven't been completely useless here, have a read of this thread.

http://www.hpiforums.com/viewtopic.php?t=7274&start=105

If you flick back a page or two you might pick up a few thoughts on the FR21, "Laterilus" there owns an runs one in an MBX5. Sounds like a good engine reading his comments.

 

[CorradoPsi]

ok we're cool. an informative post like this is more appreciated. that link has some good reading. however i do belive fantoms claims for their motors, simply by owning one and driving it myself. they claim 1.35hp for thier FR15, id say it actually has more. but thats a matter of personal opinion. so, another time. later.

 

[VenomousRC]

I have a guy around here that uses the FR21 and it is a really strong engine. I thought the break in was crazt too. If you go to the Fantom website, and read their reasons for this type of breakin it makes alot of sense.

I broke in my XTM21 pro and used the XTM process wich is very close to the fantom break in. It runs very strong and I just finished the 5th tank. It was very hard to do it this way, but I figured its their engine they should know.

The "old school" beak-in is for those engines that were not made to todays specs. the parts did not fit together the way they do these days. The machining processes today are much better. I am in the fabrication industry so I can vouch for this.

Darin Gray
RCSX EUGENE OR :beer:

 

[Nitro_Freak]

all i know is that it has a very good chance of being my next engine after my .247 wears out!!

 

[niggle]

Some good points raised here (amongst the flames!).

Until someone like Team TWF8 gets their dyno up and running and starts publishing torque curves we'll just have to go with what the fast guys are running.

Torque is important for 1:8 buggies, it's what gets us off the line and pulls us out of the the slow corners, it's why off-road engines tend to be square or undersquare (long-stroke) in terms of bore/stroke ratios. The on-road guys race on smooth, flat, high grip tracks, carry a lot of speed through corners and use two-speed transmissions. They don't need as much torque and short-stroke motors work well for them.

Admittedly, high engine speed is important too because we only run single-speed transmissions and limited pinion/spur combinations.

Note that HP is just torque calculated/expressed at a given engine speed. 3.0HP @ 50,000RPM might sound impressive when tested with no engine load, but this might equate to a less-than-impressive torque figure and there may not be enough torque to overcome driveline friction, air resistance and tyre deformation at this speed. It is quite possible that your 50,000rpm engine may not attain anything near this engine speed on the track. The torque curve would tell you this before you decide to purchase/install the engine.

I seem to remember a couple of years ago, the Fantom .12 and .15 engines were well thought of, not only for their incredible speed but also for their reasonable price.