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[john54]

Hi All
Been running a Dateline Manta (subdrive) with 700bb turbo & 14 cells.
In my quest for warp speed fitted brushless (3000 revs per volt) 60amp e.s.c 14 cells = 42000 ish r.p.m (off load)
Tried props from 25 to 40mm go's like stink with all of them.
Motor getting to hot for comfort so i need to watercool it.
Where would be the best place for the intake  without causing to much drag ?
As you can see she's wide 9in & low profile 1.5 in
Hope someone can help.
Regards

John 

[Martin (Admin)]

What about a brass or copper pipe that is at an angle and flush to the hull bottom?
Fit somewhere near the transom ie. the 'wettest' part of the boat.
Remember you don't actually need loads of water cooling so the tube only needs to 2 or 3 mm Smaller the better to reduce drag.l

PS. Ellipse is hole inlet seen from under the hull.
PSS. Is it still vogue to make the transom hull joint as sharp as possible?

[john54]

Hi Martin
Sounds a good idea i have only used premade in/out kits from model shop's ect on scale boat's where drag is not really a serious issue.
As for the transome / hull thing never tried it ! Somebody on here must have done if so is there any advantages ?

[2772e]

If you have a look at Iansboats he does a twin water intake that fits flush with the underside of the boat, causes almost no drag and is very effective. similar to the previous post but built specifically.

Regards

Simon

[omra85]

Martin's spot on (as usual)  ::)
The best intakes are sloping tubes which can be flush giving the ultimate in low drag, or left a little angled for more flow (depending on what you're cooling.  These were mine on a 3.5cc racer, one for the crankcase and head, the other for the manifold and pipe. You would only need the one.  If you use 3mm tube, silicon water tube holds firmly (with a cable tie, of course).
Discharge over the side of the deck up near the motor, where you can see it when the boats kicking up some spray.
Transom corners which are dead square help keep the boat flat and create a clean break for the flow under the hull, thus reducing drag.  With what you're sticking in there, sounds like you'll need all the control you can get  
Good luck
Danny

[Martin (Admin)]

Martin's spot on (as usual)  ::)

Really?? Rock on!!   

[john54]

Thanks Guys
Will keep you posted.

[Bridkid]

If you are going to fit a water cooling inlet then please make sure there is nothing protruding from the hull bottom to cause drag. Once you have fitted the tube (5/32" aluminium is best) file a groove along the length of the hull for about 1" going to a point towards the bow so that the water runs up and into the tube. The last thing you want is for a piece of tube sticking out to 'catch' the water. (too much drag) I have fitted more of these than I have had hot dinners and it should be very effective in keeping the motor cool, with a coil of course.
Cheers,
Have fun,
Ian.