gaz to brushless conversion - RC Groups
Thread Tools
Jan 27, 2010, 08:23 PM
Registered User

gaz to brushless conversion

Hi guys! I want to convert my 40" gas crackerbox to brushless! can someone help me choose the right motor? It will be on 16.5v a123 battery....

Sign up now
to remove ads between posts
Jan 28, 2010, 01:41 AM
Registered User
cyberhoops's Avatar
Depending on money...

Fiegao 580 7L and Turnigy 120 amp controller would be my less expensive choice assuming a battery capacity in the 25C 4500mah range or better.
Jan 28, 2010, 02:40 AM
NeverAgainVolunteerYourse lf
nick_75au's Avatar
Biggest 1000Kv motor you can find, will put out the same RPM at that voltage as a mod Zenoah or equivalent
( if its a Home Lite or equivalent motor the 600 Kv outrunners will give the same performance at your specified voltage).
Need 1500 watt motor minimum to run the same props, there isn't much around that both cheap and powerful. If you can up the voltage, quite a few lower Kv outrunners become within specs at around 600 Kv Little Screamers have come up with something that looks very nice

Jan 28, 2010, 04:33 PM
Registered User
hi will this work for zippkit rockett 48"
Jan 28, 2010, 05:41 PM
Registered User
mxz70017's Avatar

Need more power

There's no way the motor he posted. Is any where near the power of a Zenoah GPM 260 26cc Gas engine!!A rating of a .40 to a .61 Nitro wont do It.This one will....
Jan 28, 2010, 10:33 PM
NeverAgainVolunteerYourse lf
nick_75au's Avatar
Maximum speed of the motor you posted is 8160 RPM at 48 volts, has the power but is too slow,(at O'Ps voltage its going to only be 2800 RPM, great for a 1:10th scale tug) the little screamers motor is rated 2000 watts higher at 8000 watts but needs at least 8s(30 volts) to match the Zenoah in speed, if you prop it to 8000 watts it's about 30 percent more powerful than a Zenoah!

Note I said if its a Home Lite type motor the 1500 watt motor is equivalent (actually much better)

Realistically there's no "cheap" motor that's going to work at the OP's specified voltage, some of the Neu in-runners will do it at $300 plus though there may be others I don't know about.
The best match I can find is a Neu 2215 1.5Y at 1050 Kv, $529 at Castle, 2500 watts continuous( about 1000 watts less than a Mod Zenoah), propped to this wattage at 16.8 volts its going to draw 150 amps.

Jan 28, 2010, 11:17 PM
Registered User
mxz70017's Avatar

True Nick

That Is true there's really no cheap way.To make up for a gas powered motor.The motor or the battery to make that power.He state's 7 laps how big?16Oz of fuel In either of my 26cc Zenoah GPM 260's.Will Give you 45 minutes run time.How many battery's will It take too do that?LOL....Also my Bonzi stuffed crank an large bore carb.An that set Up An propped well!!!There's not too many electrics that will stay with It...An If they do It will still out run them In time.An I still don't believe all the numbers. They put out here either!!!

But I do have a 55 Shockwave hull stripped!!Im watching this an scream's thread.I may now have 3- 26cc motors sitting on the bench!!!!If things look good enough to go electric...Nothing Ive seen yet has.I like the run times!!! Not look Its green for 5 minutes!!!!That motor my Bonzi ok.With a new clutch was just Under $400.An say $3.00 for gas an 2 stroke oil.Will get me 6 hours of run time for 3 bucks!!!!!What amount of time an electric power would It take to get that???To charge the battery's.. High end speed control..Lipo power,cut off for lipos!!!Cooling an hope It don't get weeded an go poof..Gas still looks like the better way to go.Or spend the afternoon watching gas boats. Run when your battery's are dead!!!!!
Last edited by mxz70017; Jan 28, 2010 at 11:31 PM.
Jan 29, 2010, 11:50 AM
Registered User
I agree that gas will run longer BUT not everyone can run a gas boat in there area. Also for racing all they needed was 7+ laps I do not think they ran it down to empty, I was just stating that in full race mode it will run the 7+ laps needed to complete the race at full throttle. If you were to prop it down a little and not run full out the whole time, Run times will be much longer. All the testing so far has been for racing. I have a ESC coming for the 55" Shockwave and will start soon finishing it. This motor and it's testing have been guarded by the gent getting ready for this race season and getting info from him is tough! He is out to win! You can run 12s if you want but for this class 10s is it. At a MSRP of $179.99 and on intro sale now for $149.99 I was trying to make it adorable for everyone no matter your budget. Race,Conversion or just for fun.

Jan 29, 2010, 08:17 PM
Registered User

race boat

i just started a zippkit rockett 48" long hoping to use this motor set up could use help on any ideas on motor esc prop etc ,we cant use gas by us so i have to go this route ,i am not looking for all out speed but enough to get on plane and about 15-20 minutes run time thanks rye
Jan 29, 2010, 08:43 PM
NeverAgainVolunteerYourse lf
nick_75au's Avatar
Hi Rye,
The 1500 watt outrunner I posted earlier will work, I have a feeling though the runtimes will not be enough, on 5000mAH batteries you will get about 10 minutes runtime on a reasonably conservative prop.
Jan 29, 2010, 09:05 PM
I feel the need for speed!
scorpion1's Avatar
This motor may work on the 5s A123's your going to run. It pulls some major amps.........i have one in a 45" Dumas. Its gonna need a large ESC.......

It will run in the mid to high 20k range unloaded.

You may also want to look into this in the 1Y version, kinda pricey but top notch
Last edited by scorpion1; Jan 29, 2010 at 09:23 PM.
Jan 29, 2010, 10:07 PM
Registered User
mxz70017's Avatar


I hear yah on the gas!!Your right not all can run them.Can I make a suggestion to you on the Shockwave?I see a bit more flex shaft exposed. Then In my Opionion should be.Take your motor mount ok Mark In from the bend thats there now.Enough for some rubber vibro mounts.Make another bend ok at the mark.Flip the mount around to then allow for the new bend an the rubber spaceing mounts.An then shorten the flex cable.An the shaft log If you need to an add A thrust washer an a stop collar.It will save you from losing the shaft as well.This new adjustment will also give you some needed anti vibration On that large motor.I wouldn't leave It bolted solid to the Ply motor mounts..Just my 2 cents!!!
Jan 30, 2010, 12:04 PM
Registered User
mxz70017's Avatar


Maximum speed of the motor you posted is 8160 RPM at 48 volts, has the power but is too slow,(at O'Ps voltage its going to only be 2800 RPM, great for a 1:10th scale tug)

So just because he has a battery. At a specific voltage that's what determines what he needs to push the boat??I don't think so....The motor you posted wont do It.I myself believe you should get more power(the battery).An a motor that will push the boat's weight...
Jan 30, 2010, 06:45 PM
NeverAgainVolunteerYourse lf
nick_75au's Avatar

Long winded resoning on motor selection

First question answer is yes but see below. The motor I posted will push the boat just fine, not at Zenoah power but I said that in my original post I don't know what the OP's original motor was. When he gets back we might find out what he has and wants out of the boat, maybe he's not into racing and just wants a fun boat.

Voltage is very important, and brushless Kv ratings make selecting motors a whole lot easier. mAH is the size of the "Gas tank" Volts and amps drawn determine the Horsepower. Volts also determine the RPM of the motor using the Kv specification
Lower volts means higher amps to achieve the same power, that's why I suggested upping the voltage, to get 6000 watts at 16 volts is 360 amps. You need a 1000 Kv motor at 16.8 volts to achieve 16000 RPM there just isn't a motor (well maybe a Neu could) that can do that.

1500 watts is equivalent of just over 2 Hp which is more than most whipper snipper motors, which are lucky to reach 10000 RPM and usually not much more than 1 HP (Biggest FS 200 Stihl is 1600 watts, most are 750 watts)
2400 watts, gets you stock Zenoah power (12000rpm 3.5 Hp)
5600 watts gets you into mod Zenoah power (17-18000 RPM 7.5HP)

6000 watts at 37 volts (10s LI-PO) is still 160 amps so as you say big capacity batteries needed for a Zenoah killer in terms of power but wont be a killer in run time and cost.

Low voltage, high amps or high voltage, low amps does not change the number of batteries for the same power, low volts needs battery banks in parallel, high voltage needs batteries in series. High voltage is better because it reduces stress on components, smaller wire and lower amp capacity ESCs.


Jan 30, 2010, 08:30 PM
Registered User
mxz70017's Avatar


Nick your right again!!!!!Just got out my Calculator ~~~..Yes Sir that will work.............Thats what the description says too!!!!!HEHEHEHEHE... Capishe!!!

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Brushless Conversion - HELP!!!! PLZ PolarCap Coaxial Helicopters 4 Feb 21, 2010 12:01 AM
Discussion yokomo mr4tc ssg brushless conversion troyzero Electric Power Cars 5 Feb 10, 2010 09:32 AM
Sold FOR SALE: $800 Team Losi 8ight-T Brushless conversion RTR SPEKTRUM DX3S Quad_Addict Cars - Trucks and Parts (FS/W) 4 Feb 02, 2010 12:54 PM
For Sale Brushless Conversion Set for PZ Sukhoi, P51, etc. scharlach Aircraft - Electric - Micro & Indoor Airplanes (FS/W) 6 Jan 23, 2010 04:54 PM
Discussion Brushless Sky Hawk Nitroplanes conversion? xelaxor Electric Sailplanes 0 Jan 18, 2010 02:09 AM