Best water pick-up ever!

[SweetAccord]

the french fry analogy is the best analogy ever!

if you stick a french fry out a window while driving, eventually it will cool down. the faster you drive the quicker it cools down. so you either need more time out the window or more speed to get a cold fry. are we all in agreement here?

Not if it's a fry from McDonalds, they get cold really fast on their own! LOL

[Brushless55]

Not if it's a fry from McDonalds, they get cold really fast on their own! LOL

[wraith]

Well, Im sure Ill get flamed for chiming in on this, since Im a newb and all...

I used to build water cooled presses for making chlorine tablets. They just have a 3/4in. NPT inlet and outlet for the water. Three of these things running 24/7 use a *!***!***!***!**load of water. We tried restricting the flow to use less water. We choked down the outlet on the unit to 1/4in. ID pressurizing the cooling system. All it did was overheat the unit.

Constant flow of cold water = better cooling

[Brushless55]

Well, Im sure Ill get flamed for chiming in on this, since Im a newb and all...

I used to build water cooled presses for making chlorine tablets. They just have a 3/4in. NPT inlet and outlet for the water. Three of these things running 24/7 use a *!***!***!***!**load of water. We tried restricting the flow to use less water. We choked down the outlet on the unit to 1/4in. ID pressurizing the cooling system. All it did was overheat the unit.

Constant flow of cold water = better cooling

I wont flame

[Joeyhatch11]

So what MM tubbing do I need for this water pick up system?

[TotalPackage]

Simple answer, no.

Delta T in the equation will increase at a rate relative to decreased flow rate. The slower the flow rate, the LOWER the delta T will be between the heat source and inlet water, which lowers the cooling efficiency. What I'm saying is by raising the delta T in the equation, "M" will always be lowered at a greater rate, resulting in a Lower Q. It wont work to a greater degree becuase the delta T between the heat source and inlet water temps is less. Its not physically possible.

Sorry but what kieth is sayin is not opinion it physics and it doesnt change for anyone . Let it go keith coa all anyone has to do is open up a physics book;read it and prove it to themselves. Your wasting your time when people argue with basic physics. To be honest i think the smaller orafice at the end of the line ensures a constant flow with no air pockets and thats why it does a better job. And when it done right it wont be a trickle it will be a nice small pressured stream. The velocity increases inside the small orafice.

Simple you go two hoses one is 2 inches id the other is 1 inch id the same volume of water flows through the inch with more velocity than the 2 inch

[drwayne]

Larger surface area of coolant contact to sink can increase total heat transfer from the system. If sink cannot increase coolant surface area ( bigger journals) the optimal solution would be to increase water volume through them.. increase flow.
An ever so slightly smaller outlet Vs inlet will reduce aeration of that flow from pickup to lower pressure(air) outlet.
Compressed water is not endothermic.. let it flow freely......


W

[TotalPackage]

thanks doc

[lincpimp]

After reading this I have a feeling some of the variables are being left out or over simplified.

A comment was made saying that the can of the motor could be cooled "too fast" for the internals to properly transfer the heat... I do not think this can be true. Heat travels in various materials at different rates. If you put a heat gun on a piece of al sheet and then on a piece of plywood you can see the difference.

So water will conduct heat at a certain rate. And the heat will also transfer in the water. Surface shape and texture (surface area) will also determine how much heat can be transfered at any specific flow.

So trying to make a blanket statement that increased flow may or may not cool better without taking into account the other variables just will not work.

I have a feeling that you could get the water flowing too fast to properly remove the heat, but that may be well past what the normal sport boater can do with his equipment.

Increasing the volume of water around the heat source will likely remove more heat, up to a point. And as you approach that point increasing the flow may help, but you have reached the limit of water cooling, and need to redesign the system.

[Shooter]

We need an icon for "waking the sleeping bear".

Seriously though. You are right. MORE FLOW = BETTER COOLING. The point at which too much flow becomes a problem (due to flow separation and/or cavitation) is far beyond anything we would see in practice.

[Fluid]

MORE FLOW = BETTER COOLING. The point at which too much flow becomes a problem (due to flow separation and/or cavitation) is far beyond anything we would see in practice.

Wrong. Water has a specific heat value and takes time to absorb heat. Turbullent flow is required for maximum heat transfer, but cooling water moving 'too fast' by hot objects does not absorb the heat as well as water moving slower. (That's why auto engines run cooler with a thermostat or restrictor in place instead of no restriction). But the heck with physics guys - believe whatever you want. I'll just keep having the coolest components in my boats!



.

[sailr]

The typical water nipples on the cooling jacket are only going to let the water move through so fast so why are we arguing about this?

[RandyatBBY]

Fluid is right and that is always use a re-stricter hose on a J tube pick up. That is one to two sizes smaller on the outlet side.

[Shooter]

Wrong. Water has a specific heat value and takes time to absorb heat. Turbullent flow is required for maximum heat transfer, but cooling water moving 'too fast' by hot objects does not absorb the heat as well as water moving slower. (That's why auto engines run cooler with a thermostat or restrictor in place instead of no restriction). But the heck with physics guys - believe whatever you want. I'll just keep having the coolest components in my boats!

Respectfully sir, we are not trying to HEAT the water. If so, then we would surely be interested in the amount of time the water sat in the cooling can (coffee maker).

Delta temperature is absolute king here. The best way to achieve delta T is MORE FLOW. No sense having warm water sitting in the can, it only reduces the delta T and the effectiveness of the system. The water is in constant contact with the motor. I work on systems like this everyday and graduated with a concentration in cooling systems. Not trying to change the laws of physics, just supporting them.

Regarding the automotive analogy, it is a closed system with increased complexity. The restriction was there to increase the pressure, thereby increasing the boiling point.

I'm only arguing now because I can't be boating!!!

[Doug Smock]

Someone needs to tell these guys that they are going about this bass ackwards.

http://www.jrcbd.com/showthread.php?54534-Best-way-to-build-heat-in-engine

Good luck with that!!!

Shooter you are correct. If memory servers a boiler heated to 15 psi will net ya approx 250'F.

Doug
Not arguing fellas. My stuff runs cool, even my gassers.