Under Hull Water Pickup

[MarcusOz]

Hi All

I want to add an under hull water pick to my Genesis Cat.

Just wondering what people think will be the best place to put it.

Not getting much water flow through the rudder pickup.

[Doby]

As far back as possible and towards the center of the hull. You want to make sure its always in the water.

[tiqueman]

As far back as possible and towards the center of the hull. You want to make sure its always in the water.

Couldnt have said it better.

[Fluid]

If you are not getting adequate flow through the rudder then something is wrong. I use rudder pickups on most of my boats, hull pickups on a few. I find better flow with the rudder pickup. What rudder are you using?

Have you checked the holes through the rudder for obstructions? Remove the brass fitting and run a drill bit (by hand) to the bottom of the hole to make certain it is clear. Are you using the largest practical silicon tubing diameter? Any kinks in the water lines? Are the lines as short as practical?

Finally, what do you mean by "not getting much water flow"? You do not need - or want - the water exiting the boat spraying out two feet. Some folks seem to think that more is better, but in truth it is not. Excess water speed through the system reduces the efficiency of the cooling system. As long as you get a constant exit flow at least a couple inches out, you are probably fine.


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[ReddyWatts]

Slow water flow does not provide the best cooling. You are on the right track marcusoz.

[Jabbo]

I am having the same problems with my genesis I just filed the pick ups on the rudder open a little more along the side. I have not run it since but when I do I will let you know the result. I have also heard people bypassed the water cooling on the motor mount to shorten the overall length of tubing, but I have not tried that yet.

[MarcusOz]

I'm not expecting water to spray two feet out of the outlet.

I have 5mm ID tubing:

1. Neatly routed in the hull so there are no kinks

2. Shortest possible lengths of tube without generating kinks

3. I can easily blow air through the system

In spite of this water just dribbles from the outlet.

There is no visible blokage in the rudder, i have run a drill bit down there.

Its just the stock rudder that came with the boat, no idea what brand.

[drwayne]

Best cooling in when the water passing through is at higher pressure.. eg large bore pickup,smaller bore exit.
Larger fluid density for heat transfer.

5mm outlet from a small pickup .. a trickle from the outlet equals a lot from the smaller intake..

Do the electronics get hot ?
If motor or speedy are not hot after a run, why worry ?

W

5082 Oz