Water tubing size, does it matter?

[Jason4636]

I have a MG with a single water inlet. And a fantasm with a single water inlet. I get good flow thru both setups. And neither one has ever ran hot. But on the fantasm I have a smaller I.D. hose, and it shoots the water about 3 ft out of the outlet. Now the MG has large I.D. hose it only shoots it up 4-6 inches. But before I rebuild my MG it had small I.D. tubbing and it would shoot the water up like the fantasm does now.

Should I go back to the small I.D. tubing?

[MR2NR]

Oh boy here we go again :). Personally I think the length of tubing and hold capacity in each component play a role in tube diameter. All I can say is try it. I am starting large but going smaller if that doesn't work lol. Get a good test temp and then swap. When I mean good test temp I mean run the boat hard two or more batt cycles on the same day in the same body of water and measure temps after the same amount of run time at full throttle after each cycle. If your not getting hot I'd say you really shouldn't worry about it and only change if you like the larger stream. It will also help you indicate if you have a clog earlier though :)

[jamespl]

It will be all down to your smallest point. For example, your pipe is 5mm but the inlets on tour water jacket are 2mm (internal diameter) you will get a bottle neck effect when the water flow hits the 2mm connections. So it's pointless running a larger pipe if the connectors on your water jacket or rudder pickup are smaller. The faster the flow of water the better the cooling potential.

[Jason4636]

I've got large inlet and outlet, with large diameter tubing. I'll try the smaller stuff to seel if it shoots a stream higher. I do like a higher stream where you can tell if its clogging

[jcald2000]

50% increase in Dia. is twice the flow rate.