I am once again pondering a serpentine pulley on the water pump. In a quick look I was only able to find 6.25" pulleys. The stock one was 7" IIRC, making it a 1:1 drive with the crank (I do have a 7" serpentine pulley on the crank). With a 6.25" pulley that would mean the pump spins 12% faster. I don't do fluid dynamics... will this adversely affect the cooling system?

Better low speed/rpm circulation maybe? I dont really see how it could have an adverse effect,but I am no expert.

I didn't think there would be anything but I have no idea, would rather get it from someone who is certain before I go through the hassle of getting pulleys to work

Is there a limit? What if it was 30, 40, etc % faster? Cavitation issues? This is for daily driver use with the occasional romp if that makes a difference. I don't think I ever had it past 3500rpm so compared to what some others here drag at its of no concern, but this will be sustained not just down the track.

I've done a little of that stuff (can't be too much help).

If it spins 12% faster it won't be 12% more efficient at cooling probably a smaller percentage (%2) as other factors such as the amount of heat the radiator can dissipate, current environment, speed of fan, coolant type etc play a part.

My vote is it'll be fine.

The faster the water moves the less time it will be in the radiator to cool-that said it is the job of the thermostat to slow things down so you can cool your engine.

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Taking care of 57 300C conv,48 T&C conv. Missing my 67 GTX and 36 Ply coupe

If the flow rate is faster, means that the heat from the engine won't heat up the coolant as faster. 12% increase in flow will not mean 12% efficiency lost in heat transfer from engine block to coolant.

If you adjust the ratio of coolant to water I think that may just solve that problem.

This I think explains it best:

"The most common coolant is water. Its high heat capacity and low cost makes it a suitable heat-transfer medium. It is usually used with additives, like corrosion inhibitors and antifreeze. Antifreeze, a solution of a suitable organic chemical (most often ethylene glycol, diethylene glycol, or propylene glycol) in water, is used when the water-based coolant has to withstand temperatures below 0 °C, or when its boiling point has to be raised. Betaine is a similar coolant, with the exception that it is made from pure plant juice, and is therefore not toxic or difficult to dispose of ecologically."

kesteb
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Joined: 06 Nov 2002
Posts: 1232
Location: Everett, WA
Post subject: (05/12/51)


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The bottom pulley can be from a 3.8 Ford V6. An adapter needs to be made that will allow the pulley to conform to the damper. I used the adapter to center the pulley. A damper crank bolt is needed and the pulley needs to be drilled to match the damper.

The water pump pulley can be from a 3.0 Ford V6. A piece of flat stock can be used to align to the bottom pulley. The pulley needs to be drilled to match the water pump holes.

After this you are on your own on how to run your accessories.

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So were does the heat go? If it is not going into the water (because it's going to fast) it must be staying in the metal engine block? Please read what I said-the faster the water goes through a radiator the less cooling. But then I said that the flow rate is really controlled by the thermostat-not the pump.

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50 chrysler,54 Plymouth, 64 Valiant conv 4 speed, 66 Valiant V8 wagon, 70 Challenger R/T 440+6 conv 4 speed,80 Colt, 98 Neon ACR,84 Honda V45 Magna
Taking care of 57 300C conv,48 T&C conv. Missing my 67 GTX and 36 Ply coupe

Shouldn't make a difference the thermostat has the final say in what temp everything is gonna run. If you ran with no stat then the wide open hole might cause issues being the coolant flows faster but even then the water probably has enough capactiy to cool the motor more than you would like. When i drove my turbo motor around for a while before i put a stat in it ran way to cold even in warm weather for examle driving at 55mph the engine would get down to 150 maybe 160.

Kev

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I saw that post about the ford pulleys. Unless there are different pullies amongst the different years it was used, the pulley is not 7" per the pic I found online.

it should not be a problem.....unless you not useing therostat

4speed sorry I did read what you said.

The heat doesn't not go into the coolant, I said it won't heat up the coolant as fast as the coolant will move faster. Heat transfer will increase with longer exposure. Just like as you said it won't cool in the radiator as much because it's flowing faster.

I also said "If it spins 12% faster it won't be 12% more efficient at cooling probably a smaller percentage (%2) as other factors such as the amount of heat the radiator can dissipate, current environment, speed of fan, coolant type etc play a part. "

Sorry I forgot to mention the thermostat (guess it was the most important thing).

Guys you are talking gobbledygook--- 12% this, and flow that. If coolant is in contact with cast iron, heat will transfer from hot metal to cooler fluid. Doesn’t mater if it is moving a little bit faster or not in this automotive ‘infernal’ combustion application.

Cooling efficiency is determined by size of radiator, its design, and delta T (the difference in temperature between fluid to be cooled, and ambient air temperature). Delta T is generally governed by thermostat selection. The bigger the difference in temperature of air to coolant, enables more heat to be be transferred.

Increase the speed of impeller of water pump, and more mechanical energy will be needed to turn that pump. In other words its parasitic drain from power getting to the wheels is increased. This is also true of a fixed cooling fan driven by belts & pulleys off of crankshaft, after all air is just fluid.

I would not worry about the water pump spinning a little bit faster or slower it won’t make a bit of difference.

For example; a car with a high geared rear end such as a 2.xx will dictate a lower general operating rpm range, than say a car with 4.xx rear gears. Both cars don’t over heat, but both water pumps turn at much different rpm for same road speed.

So keep a 50/50 mix circulating, a 14 lb cap, good general repair of cooling system, and “forgetaboutitâ€￾.

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