Neu motor water jacket

[Eodman]

Has any one noticed that the fittings on the water jackets have a smaller diameter?

Just received 1 from Steven and I either have to change the diameter coming from the esc(Castle) or neck down to a smaller hose for the fitting on the water jacket!

I compared the fittings on my earlier jackets and sure enough ... the new ones are smaller ... they are at right angles but smaller OD and ID!

Anyone else notice or experience this!

Now my next question/problem is what does that do to water flow? Decreased ID should surely decrease the amount of water passing thru it !

Anyone????

[Eodman]

Help

Anybody notice this

[Boatman]

I notice they are quite smaller than the jackets for the Feigao XL's he sells here. I just figured though that as long as the motor has water around it it is still cooling properly. Just my opinion but, yes I do notice the fittings ave quite small I.D.

[Fluid]

The fact is that cooling water should not pass rapidly through the ESC or motor cooling systems. Because of the high specific heat of water it takes time to absorb heat - passing too rapidly through the ESC for example will not allow it to carry away nearly as much heat as if the water moved more slowly through it. But what the heck, it's just physics and everyone knows that the faster the water moves the better the cooling must be.


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[Flying Scotsman]

Jay, you crack me up. Way to go on physics. Lads, this guy knows his stuff and well deserved... I hope to see you on RRR. You are missed!!

Douggie

[Boatman]

The fact is that cooling water should not pass rapidly through the ESC or motor cooling systems. Because of the high specific heat of water it takes time to absorb heat - passing too rapidly through the ESC for example will not allow it to carry away nearly as much heat as if the water moved more slowly through it. But what the heck, it's just physics and everyone knows that the faster the water moves the better the cooling must be.


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Why do racers and engine builders install HIGH-FLOW water pumps on their engines? I dont think these boats will tell a difference of a few pints but just curious. I see you are well like here and wont be proven wrong but would like and explanation. Thanks

[Rex R]

I've seen an engine overheat untill the thermostat was re-installed (which slowed the flow). as jay has mentioned a time or three, too high a flow will not cool as effectively as a somewhat slower flow rate. the trick is to find the right rate. also note that since we don't(shouldn't) run temps past the boiling point...we don't need high pressure either .

[ReddyWatts]

The myth of velocity originated among those unschooled in physics or
thermodynamics, I suppose, because a common racer "solution" is to
press a fixed restriction into the thermostat housing neck when no
thermostat is desired. The conventional (but wrong) wisdom is that
the restriction "slows the water".
In reality, all it does is provide some more dynamic pressure in the
block by restricting the flow. The exact same result could be
accomplished (assuming the water pump doesn't surge or cavitate)
with a higher static pressure (cap pressure), assuming the system
could withstand it.

[Eodman]

Hey guys I'm not looking to start an argument, Its just something I noticed!

I purchased a H & M mono off ebay last year, finally got around to running it ... neu motor did not have cooling jacket on it! Orderd one from OSE it came in and as I was putting it on I noticed the difference!

Don't want to burn another Hydra 120! That's all!

When I ran it last week I had great water flow, this time I put the jacket on and after 1 lap I couldn't see water flowing! So I'm asking!

Thsi boat has Neu1515/1d and hydra 120 just don't want to lose a motor!

[HRC]

Thought I would chime in, great topic guys. The 90 degree fitting is for 1/8" I.D. tubing just like the older streight fitting. Yes, they are smaller.
90= .130 O.D. and .080 I.D.
streight = tripple barb .150 + O.D. and .100 I.D.
We changed to the 90 due to clearance and build problems being reported. After a lot of testing, to help make up for some of the 20% + flow loss the spacing of the holes on the jacket was changed to allow max. heat transfer using the 90 degree fitting. Hope this helps.
Dave

[Fluid]

...neu motor did not have cooling jacket on it!.....Don't want to burn another Hydra 120! .....When I ran it last week I had great water flow, this time I put the jacket on and after 1 lap I couldn't see water flowing!

First, for many applications the Neus don't need watercooling as long as the cooling holes aren't blocked - lots of racers don't use watercooling. That's largely due to the short time a heat lasts. There is nothing wrong with installing a cooling jacket on any motor, but cooling the motor won't directly cause an ESC failure. Indirectly it could cause the motor to lose its magnets, which will lower its efficiency and can/will destroy ESCs. Ask me how I know!

IME you don't want the water spraying past the outlet three feet. As long as there is at least a steady trickle you are probably fine. Like Rex said, finding the "perf" flow rate is tough, but a long stream is not it.

Don't confuse volume/pressure with circulation rate. The waterpumps used in most all internal combustion engines are not positive flow pumps, they are limited in the pressure/flow rate ratio they deliver. Many race engines use much larger radiators which have much longer tube lengths and coolant volumes, so the presure loss is higher. It takes a larger pump to move the extra water through the increased restrictions.

That's all for the physics lesson - believe it or not, your choice.

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[ReddyWatts]

Think about it. The pump is where the coolant enters the block. The thermostat is where the coolant leaves the block. Restricting the flow increases the pressure in the block, not the radiator. It has nothing to do with water flow through the radiator. The increased block pressure that helps the heat transfer. Slowing coolant flow to help heat transfer is a myth, research it.

[Boatman]

Hey, thanks also. Makes much more sense now in the terms you have put it. I especially like that the Neu motors don't absolutely need water cooling however with mine mounted as it is the holes are blocked so I will anyway. Thanks to Eodman for bringing up the topic.