Suggestions on Secondary water pick up on a hydro

[tlandauer]

I run a TFL Popeye hydro , motor is Neu 1515 1y. The temp is higher than I would like to see ( 130-140F*) on the endbells and the set up is ok, temp issue stems from not enough water volume due to the small pick up from the rudder and the water exit fitting that TFL uses.
I would like to add a prop wash pick up. If it is, how far does the tube ( pick up) have to extend behind and above the prop?
Is that a good idea?

[properchopper]

135 - 140 degrees isn't all that bad a temp although Neu motors rarely get very hot unless you're really loading them. I'd loosen up your setup - extra watercooling won't correct a setup that puts too much grunt on the motor.

OTOH since spec motors have become notoriously heat-sensitive I didadd a second line to my spec-powered rigs (and propped down). I made the pickup tube height adjustable

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[tlandauer]

Thanks, Tony!
You are right about the root cause of temp. My MM has the same motor and runs alot cooler and it is a cat. I thought hydro has less drag.
Thanks for also posting these pictures! I remember seeing them and they kept me awake all night because I had touble searching for them.
May I ask what kind of aluminum arm did you use, looks fab!!!

[785boats]

Surely a dual pick up rudder would be better. I run 4mm ID hose through my boats, & try not to use those fancy water outlets, Just a bit of 5mm tube.
Of course the flow is restricted by the smallest fitting in the system. Usually the nipples on the motor jacket, rudder, or the ESC.

[tlandauer]

Well, the dual rudder would be the easiest fix but Chris said he had clearance issue on the Popeye. I already ditched the TFL inlet and put a brass tube as an inlet ( forgot the size) but bigger than the "fancy fittings"
As much as I love the HRC jackets, I am using a cheap Leopard Jacket because it has bigger nipples.
When I first ran the boat with a 4074 Leopard 2000kv, the temp was barely 110 degrees, same prop: X447/3, I did even run the Y547 as I got the advice from you, awesom prop too.
Thanks Paul!

[kenrid]

And of course, in the Southern Hemisphere late summer (today) (eg Brisbane and Perth) the ambient water temperature is already quite high - perhaps 25degreesC (77F) limiting cooling effectiveness, so dual pickups with as large a bore as feasible are mandatory IMO.

[properchopper]

Well, the dual rudder would be the easiest fix but Chris said he had clearance issue on the Popeye. I already ditched the TFL inlet and put a brass tube as an inlet ( forgot the size) but bigger than the "fancy fittings"
As much as I love the HRC jackets, I am using a cheap Leopard Jacket because it has bigger nipples.
When I first ran the boat with a 4074 Leopard 2000kv, the temp was barely 110 degrees, same prop: X447/3, I did even run the Y547 as I got the advice from you, awesom prop too.
Thanks Paul!

Tim,

putting bigger fittings on the HRC jackets isn't hard. Bring yours to mi casa and if you need some done I can install the 10-32 Aeromarine style or the 5mm Leopard style ones for you

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[Fluid]

Tim, opening up the outlet may help since it restricts all the flow in the system. Can you open up the holes in the rudder? What is your average amp draw with the current setup?

I find it hard to believe that your high temps are due only to inadequate water flow, particularly with the low water temperature this time of year. When we race in the Texas summer the surface water is about 90*F (32*C) and we seldom see motor temps higher than that after a heat race. Past a certain point more water flow does no good. It seems your Popeye is running with more drag than it should have, referencing the same motor in your MM.


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[tlandauer]

@ Tony,
Thanks! I will bring them over when I come over !
@ Fluid,
Thanks for the input. I don't have any logger to have accurate readings. According to the OSE "calculator" I should be pulling 160 amps.