DIY electric water pump - on the cheap

[Cobb]

I agree with Jeff, use the electric motor to run the ac and other stuff you find useful like power steering depending on vehicle weight. I saw ditch the adrino crap and just rig it up to work on 2 12 volt deep cycle batteries. This way you can run it on 12 volts for low speed and 24 volts for high speed by wiring up a dtdp switch for one way or the other. K.I.S.S.

[sqidd]

Originally Posted by oil pan 4

An actual purpose built electric coolant pump isn't recommended for street use but I have ran mine up 12 hours at a time driving from New Mexico to Virginia. So electric motors and pumps aren't the problem.
I see potential problem with that motor controller.

I've been running 55gpm Meziere pumps on all sorts of applications for years. One of my cars has one for engine coolant and two for the air to water intercooler system. The ones that I have worked with have thousands of hours of use on them, lots of people use them on their daily drivers. I have yet to have one fail.

I've also been using the Davies Craig electronic pump controllers for as few years on multiple applications. Zero failures there either.

They are not inexpensive though.

I just started using Davies Craig EWP150 water pumps. Those are a bit more budget friendly. I don't have thousands of hours on them, but before I started using them I looked around. They seem to be pretty much bulletproof.

[oil pan 4]

Here is one for you:
http://ecomodder.com/forum/showthrea...tml#post297056

"Super Chevy did a water pump dyno test and didn't even report results from below 3000rpm, because they couldn't measure it."

So turn the coolant pump at around 2000RPM with crank shaft torque or electrical power and you should be good to go.

[serialk11r]

Originally Posted by oil pan 4

"Super Chevy did a water pump dyno test and didn't even report results from below 3000rpm, because they couldn't measure it."

The power the pump uses at 6000 is going to be something like 8 times greater than at 3000, so it's not unreasonable that they'd have trouble measuring it.

But just because they had trouble measuring it doesn't mean it's not significant. A few hundred watts is a solid few tenths of a gallon per hour.

Anyways I would look at the pulley diameter ratios and just run the water pump as fast as the OEM pump is when the engine is spinning at 2000rpm. I've heard people say that flow doesn't increase much past 3-4000 rpm on most engines, and you would think that they'd build in enough safety margin at 2000rpm. Maybe wire it up so that it pumps more water at higher throttle positions or something and slows down to 1200rpm otherwise.

[sqidd]

Originally Posted by serialk11r

The power the pump uses at 6000 is going to be something like 8 times greater than at 3000, so it's not unreasonable that they'd have trouble measuring it.

But just because they had trouble measuring it doesn't mean it's not significant. A few hundred watts is a solid few tenths of a gallon per hour.

Anyways I would look at the pulley diameter ratios and just run the water pump as fast as the OEM pump is when the engine is spinning at 2000rpm. I've heard people say that flow doesn't increase much past 3-4000 rpm on most engines, and you would think that they'd build in enough safety margin at 2000rpm. Maybe wire it up so that it pumps more water at higher throttle positions or something and slows down to 1200rpm otherwise.

I agree with all of that^^^^^^

Most mechanical pumps cavitate at higher RPM's anyway. They are set up to provide enough coolant flow at idle, low engine speeds, etc. When you spin them up they get out of their efficiency range.

I have a car with an electronic pump controller. It amazes me how little it actually runs the pump to maintain temp.

[BobS]

Daox
Since sqidd has a car electronic pump controller, perhaps you could get his type of controller at a U Pick Um. Might I suggest that you can arrange a large wattage resistor parallel to the controller with a DPDT switch to select the resistor if there is failure of the controller.

[sqidd]

Originally Posted by BobS

Daox
Since sqidd has a car electronic pump controller, perhaps you could get his type of controller at a U Pick Um. Might I suggest that you can arrange a large wattage resistor parallel to the controller with a DPDT switch to select the resistor if there is failure of the controller.

It's aftermarket.

It controls the water pump and a fan(s) (if you want it to), It's pretty trick.

EWP & FAN DIGITAL CONTROLLER 12V - PART No: 8020

[Daox]

I'm familiar with the Davies Craig pumps and controller. I researched them when coming up with this project to see how other companies programmed their water pump to operate.

[Daox]

What would be the benefit of using an A/C clutch?

[oil pan 4]

I would never run the engine with out the coolant pump turning.