40inch mono v hull motor

[Jean77]

Hey guys,im busy building a mono vhull and war wondering about a brushless motor that has enough power to make it go real fast.first choice was the turnigy 5692 but i just cant find one in south africa,so the guy at hk recommended the hk3674,1660kv,2-6s,1600w power.you guys think this motor will have enough power to swing a prop of maybe 63mm or more without getting to hot.im using a 180-200a esc.thanx

[martin]

That is bad advice from HK, the 3674 motor is way to small for a 40" mono + 6s on this motor in this size hull is also bad advice. & as for recomending a 63mm prop they clearly have no idea what their talking about.

[znus]

LOL!! 63 mm prop on a 3674. Props that size is normally for 26cc gassers.

I think you'll need a 4082 at the very minimum. A 1250 kv on 6s2p and a 45-47 mm prop would get you about 60-70 km/h.
Or, if HK ever stocks up on their 5692 again, a 1320 kv on 6s2p and 47-50 mm prop would be nice too, and you'll probably be doing something close to 80 km/h.

What speeds are you aiming for?

[Jean77]

Just to clarify,it wasnt advice from hk themselves but from the guy that own the hk franchise here.im looking for speeds above 60km/h.i just cant seem to find those big motors or im looking in the wrong places

[znus]

Just to clarify,it wasnt advice from hk themselves but from the guy that own the hk franchise here.im looking for speeds above 60km/h.i just cant seem to find those big motors or im looking in the wrong places

Well, if you're able to spend a few more bucks then OSE sells the Leopard 5692 1340kv and right now you'll get a free water jacket with it.

http://www.offshoreelectrics.com/pro...o-5692&cat=148

It's a big @ss motor! Make sure the rest of your drive line is up for the task.

[Jean77]

Ok thanx alot i appreciate the input.im really new to this so any help appreciated!next thing is the prop pitch on a 47 to 50mm prop?

[znus]

Start with some plastic props...

http://www.offshoreelectrics.com/pro...d=ose-3bld-316

.....and try them out before spending $$ on metal props. They might not hold up for very long but they should atleast tell you if you're in the ballpark. And 47 mm - 50 mm is for a 5692, not a 4082. If your settling for a 4082 then get a 45 and a 47 of these

http://www.offshoreelectrics.com/pro...d=ose-2bld-316

[Jean77]

Ok thanx i get what your saying.so the esc i mentioned woule be good for any of these motors?

[Make-a-Wake]

If you are going to be happy with 60km/h then you can run this 4074 from hobbyking on 4s with an x442 or an m445 and get around 70km/h out of it without straining the system, but a 4082 would be perfect, you can get those in Leopards, but the 4082 is out at Hobbyking.

Run it on 4s with a T180a ESC

http://www.hobbyking.com/hobbyking/s..._Inrunner.html

http://www.hobbyking.com/hobbyking/s..._Boat_ESC.html

[Jean77]

Ok so next thing,when mounting the motor what is the best way,shaft exiting the hull as straight as possible or should it be angled down a little?

[Make-a-Wake]

If its going to be a fixed shaft tube then i would angle it down just a bit, i have a few boats with fixed drivelines and they run well this way.