Motor choice. MHZ Scorpion, SSS or TP.

Hi Guys.

Im trying to decide on a motor for my MMP Trident F1 hull.
First of all, im not going for speedruns.
Its a raceboat, and will be raced against other boats of the same type.
We are four guys here in my area who has bought a hull each, and we are going to race the shizzle out of them! :w00t:

So handling and run time comes before insane top speeds.

The field have been narrow down to three motors.
MHZ Scorpion 5035/760KV (watercooled offcourse).
SSS 5694/850KV.
TP 5850/850KV.

All three used with 10cells.
Maybe 8 if it goes totally south with too much power :laugh:

But i/we have heard some different experiences about the different motors.

MHZ Scorpion tends to get hot and not easy to cool.
SSS not the best quality, but good performance.
TP very power hungry. Drains batterys very quickly and have very high amp draw.

Can somebody pitch in with some experience?

The Scorpion motors are high quality but like all outrunners are a challenge to cool. Watercooling can only be done (practically) on the mounting plate so watercooling efficiency is not the best. That said, if run on an outboard without a cover the resulting air and splash cooling should work fine. Scorpion uses very high quality magnets and wire, so they can take higher motor temperatures than an inrunner. They are also much easier to dry out after getting wet (and they will get soaked) than an inrunner, a factor to consider for motor longevity.

SSS motors are built to a lower price point than the others and perform accordingly.

TP motors are no different than any other motor, the higher the load the more amps they draw. TP have a higher efficiency than the SSS motors (meaning they turn more battery energy into motion rather than into heat) so will run cooler under the same load. This “amp hog” power hungry nonsense is based on folks putting huge props on motors - because they can - then complaining that they draw too many amps.

The TP has a higher amp rating than the other two, 200 continuous versus 150 for the others. But that is still a lot of power and will give longer run times. Note that the amp rating is not the maximum amps the motor will draw but rather the maximum the manufacturer recommends for good motor life. Put on too much prop and you’ll fry motor, ESC and possibly the batteries.


.

Hi Fluid :)

I will run the motor on a MHZ outboard Z-drive, but it will be with a motor cover. So the air and splash cooling will not be present.
But i could make one or two air intakes in the cover, to scoop in some air. And maybe some vent holes on the backside also, to draw out hot air.

The MHZ Scorpions are made with watercooling in the mounting plate, if you didnt know that?

Regarding amp rating, the TP 5850 and SSS 5694 actually has almost the same. 210A VS 200A.
But the scorpion is 150A as you mentioned.
Or am i missing something i cant see from the spec sheets?

Thanks you for the clarification around these motors.
The "amp hog"-talk had me doubt in the TP. And cooling issues with the scorpions also made me doubt in them.
But i guess its down to those to brands now. SSS is out! :thumbdown:

Air inlets in a cowl are worthless without corresponding outlets, ask any scale airplane guy. Oh, and the outlets have to be bigger than the inlets.

The manufacturers are never clear on their motors' power ratings. What matters is watts (watts = power) and this will vary depending on voltage and amps. The MHZ SSS motor is 'rated' to 8000 watts, but this is the "burst" rating, not continuous - maximum continuous is about 6000 watts and this is what we care about for oval racing. 6000 watts on 10S is 160 amps, but 6000 watts on 6S is 270 amps. See the difference?

I like both Scorpion and TP motors. I have run a Scorpion 4025/1100 for years in my 6S Sprint Cat without water cooling, just a computer fan blowing air across it. In a two-minute heat it doesn't get too hot because there is enough air volume in that hull to keep the temps reasonable. And I keep the amp draw between 110-120 amps (it's rated for 100 amps). I wouldn't use it for a long offshore heat.

I have used the TP motors for about five years and have had good luck with them in high-power setups (over 185 amps). They are easier to cool than an outrunner and that's needed since they can handle more amps. But in an outboard I don't know which would be best for you, both types have been used successfully.


.

No problem making the outlet bigger than inlets. The cover/cowl is plenty big enough for it.

I think i can follow you.
MHZ Scorpion 5035/750 rated for 5800watt cont, and TP 5850/850 rated for 6500watt cont.
From what i can read and understand, TP 5850/850, 800 or maybe even 785 or 720KV is my weapon of choice. Cooling will not be a big issue, and it will work for sure. I can always try out the Scorpion later on.

850KV and 10S, 800KV on 10S, 785KV on 10S or 720KV on 12S.
Those combinations should give me between 29000 and 32000 RPM.

Am i on point here or heading in the wrong direction ? :laugh:

Actual rpm on the water will be lower than Kv x volts, motor/battery efficiency will reduce that. Expect around 24,000 to 26,000 rpm at a reliable amp draw. I haven’t run a 10S OB tunnel, but similar-sized cats runs very well with 785 or 800 Kv and 10S. A good prop to start with is an x460. You may be able to run a more aggressive prop, or for extended runtime you may want to drop a bit. Always start with a smaller prop for safety, it beats burning down your ESC. With a good 800 Kv motor in a one-mile heat, an x462 or equivalent might work great.


.

My experience is that water cooling on an outrunner does not make any real difference, ( no cooling of stator/rotor). An air intake does. Think the limet for the scorpion would be around a 60 mm prop on 10s. Maybe a bit more if you have runs under 5 min. TP or sss ? I Think the 56mm sss is just as good as TP powervice.

The RPM i am aiming at is also unloaded. Cant remember were i got it from, but i was told that unloaded RPM around 30k, is a good place to start out.

Is that 2 or 3 blade props?
Have seen a setup on the Trident with TP 5850/600KV on 12S and a 55mm 3 blade prop. That goes very well until it flips :laugh:
But I havent really understood the difference between 2 and 3 blade.
Something about faster acceleration vs more of a smooth ride?

800KV sounds like a sweet spot with 10S.
Might go with a Flier 300A ESC.

Fluid, thanks as always for sharing your knowledge. Your contributions to threads like these are invaluable.

if it is me you are asking. I was thinking about a 60 mm 3-blade /1,4. Yes 3-blades in general have better acceleration. Remenber the scorpion has a 10 mm shaft. SSS/TP a 8 mm. At TFL they have some 56mm with 10 mm shafts if that is the outboarder edition you got.
https://www.tfl-hobby.de/Motore--Hal...L-56-mm/56114/

And acceleration is what i want when racing that oval :thumbup1:
But its not easy to find high quality 3blade props with 6,35mm drive dog. Havent had much luck yet.
I think the only place so far, is propshop.

Regarding shaft diameter.. No problem. The Z drive comes with a 8 and 10mm coupler. So i can swap between motors if thats what i want :smile:


I agree with fweasel. Alot of really good guidance and knowledge have just been shared here. Bless you sir, for expanding a newbies mind a bit :laugh:

Quote:

---

Originally Posted by BrickBait

And acceleration is what i want when racing that oval :thumbup1:
But its not easy to find high quality 3blade props with 6,35mm drive dog. Havent had much luck yet.
I think the only place so far, is propshop.

Regarding shaft diameter.. No problem. The Z drive comes with a 8 and 10mm coupler. So i can swap between motors if thats what i want :smile:


I agree with fweasel. Alot of really good guidance and knowledge have just been shared here. Bless you sir, for expanding a newbies mind a bit :laugh:

---

Just wondering with those big motors how is the MHZ lower going to hold up. Got to be hard on those gears. Can’t find anyone running one to see how they do.

I run a few big boats on 10s and I like KV between 650 and 750. But I also run big props. 67mm. If your limited to 60mm prop then the higher kv will be fine. Most of my boats run TP motors but me and a friend found out that the 6 pole TP motor eats up esc. I have burned up swordfish 300 and flier 300 and 400 esc. So has he. We both agree that 4 pole motor will be better for esc. The best and fastest esc we tried was the swordfish 300 on auto timing. I heard of someone who pointed the water cooling line to spray the out runner motor when it's running. Be sure to WD 40 after you run but not a bad way to go for cooling Scorpion motor. I never heard how well this worked or not though.