View Full Version : Is the water flow rate enough?

Nickinoue - n/a
26-Jul-06, 09:31 AM

Thanx for the help on the frame its been designed and constructed http://hovercraft.org.uk/images/icons/smiley_icons/icon_razz.gif . I am now looking towards fitting the engine cooling system. I was thinking of getting the EPB Davis Craig water pump which delivers around 13.3L/minute, i have the RD250LC and was wondering if this flow rate is enough? I have also had different ideas of where to mount the rad, most people seem to mount it on the H section in front of the fan, but i was thinking of putting it inside the plenum underneath the splitter! would this present any efficiency problems or lack of air going to the holes due to it blocking it?



pest619 - n/a
26-Jul-06, 11:13 AM
Hi, i have one of these pumps fitted on my tzr and it works fine, they also gave me a kiddy discount at Maw Solutions where i bought it http://hovercraft.org.uk/images/icons/smiley_icons/icon_cool.gif

BUT make sure you mount it the right way up- arrows on the sticker on the pump. For me it meant i had to put a 180 bend underneath the pump going towards the rad. After being mounted the wrong way up and submerged it stopped (they gave me another free on warranty).

As far as putting the rad down there, it would prob work as long as you have the rad cap high enough but its not to practical as far as cleaning and having pipes in difficult places- something iv found and anyone will tell you is to make stuff easy to get to.

Methinks Russ has done it in his racing fish but has the rad in in a cut out at the back like on some of the bigger vortexes

tonybroad - n/a
26-Jul-06, 01:20 PM
few things to consider

putting the rad in plenum has other issues other than poor access and maintenance - if your blades let go your rad is likely to get totalled

secondly it can cause airlock problems if a rad does not have it's header above the cylinder head - also if it is above and your pump fails you can still get natural flow through the cooling system (thermosyphon)which might save your engine

mounting it in front of the fan along the centreline of the fan is good because in front of the hub is a dead space as far as the fan is concerned so you are not seriously affecting air flow into the fan

hope that helps


team black - n/a
27-Jul-06, 08:19 AM
The LC runs perfectly well without a pump if you put the rad on the H frame (thermo syphon). I used the Davies Craig pump for a number of years without any problems, and I tend to think it's better than the pump most often used in hovercraft

Nickinoue - n/a
27-Jul-06, 10:10 AM
Wow, i didnt know the thermosyphon effect was that effective, i still would be more reasurred if i also added a pump cuz i dont want my engine 2 seize up the 1st time i take it out. From what tony has said im now not going to put my rad inside the plenum, it would mean its below the cylinder head and that thermosyphon will not work. The biggest point most people i have talked about hovercraft is easy maintainace so i can see why putting things in different places might have pro's nd cons.


team black - n/a
28-Jul-06, 08:21 AM
Not only is thermosyphon efficient, but on one race my battery packed up meaning no power for the pump. On thermosyphon alone, enough water forced its way passed the pump impellor to cool the engine, though it was hotter than I would have liked (97c instead of the usual 75c)