Graupner Speed 820 BB Turbo Race 20V

[hallsboats]

hi.
the motor im using at the moment is(Brushless Watercooled Motor 3650. 3300 rpm per volt) and ive been told it to much rpm to use in a 40inch hull.
so im think of running a.
Graupner Speed 820 BB Turbo Race 20V
on a Graupner 60A speed controller
any ideas if that will make my boat shift ??

thanks james

[Steven Vaccaro]

It really depends on a few things.

(1) what you want to get out of your boat?
(2) whats the budget
(3) what batteries do you plan on running?

[Simon.O.]

hi.
the motor im using at the moment is(Brushless Watercooled Motor 3650. 3300 rpm per volt) and ive been told it to much rpm to use in a 40inch hull.
so im think of running a.
Graupner Speed 820 BB Turbo Race 20V
on a Graupner 60A speed controller
any ideas if that will make my boat shift ??

thanks james

I'll take a punt here and guess that the motor is 36mm Dia and 50mm long. If so then that would make it a 540S and at 3300kv makes it roughly a 10S wind.
For your 40" hull this motor is far too small.
You need a XL size motor which is 36mm dia and about 75mm long. From here you get to choose the Kv based upon the voltage that you intend to run and the prop that may suit your hull.
The esc and packs come into the equation but can be a result of the first calculations if you are buying it all from new.

Fwiw I am very keen to get my hands on a motor like you have now, (3650-3300) It would suit one of my small 24" hulls.

[hallsboats]

il spend bout £100 on motor and speed controller .
and im planning on using Makita 18v Battery Makita 3.0Ah . but ive got a few 6 cells and 8 cells 3300Ah i think

[fragglez]

The motor in question that me nephew (hallsboats) is talking about is quite a big motor, bigger than my 700 motor : I believe this is the size of his motor Diameter 43mm, length 63mm., shaft diameter 4mm.

http://www.prestwich.ndirect.co.uk/brushless.htm

[Steven Vaccaro]

The motor in question that me nephew (hallsboats) is talking about is quite a big motor, bigger than my 700 motor : I believe this is the size of his motor Diameter 43mm, length 63mm., shaft diameter 4mm.

http://www.prestwich.ndirect.co.uk/brushless.htm

Thats the size including the water jacket. The actual motor is much smaller. The feigao 580L will get you some more speed, but a 40" boat is pretty big. So dont over prop it, or it will burn up.

[hallsboats]

im using a 45mm prop is that to big ?

[Steven Vaccaro]

im using a 45mm prop is that to big ?

Yes. What are the temperatures after running for 20-30 seconds or so?

[hallsboats]

its feels fine. no that warm.
but ive been told it to much Rpm for my hull

[Steven Vaccaro]

what cells are you running?

[hallsboats]

not sure.. its a makita drill battery 18v