DIY electric water pump - on the cheap

[samwichse]

Pierburg Cooland Pumps CWA 50 $75 - DIY Electric Car Forums

How about a cheapo all-in-one unit? Pierburg CWA 50 specs:

Voltage: 8.5 to 16 volts
Current at 12.5v : 6.5 amps
Free flow capacity: 30 liters per minute.
Capacity with 20ft head, 8.7 psi, 0.6 bar: 24 liters per minute
1/2 inch barbed ports.

How much flow rate do you need? 24L/min is a bit more than 1 gallon every 10 seconds.

PS: in reply to the pump being ridiculously easy to spin by hand: It's a centrifugal pump, so the load decreases with flow rate and you're only spinning it a few RPMS, not enough to actually let the pump be effective. Open the thermostat and spin it with a drill and you'll feel a lot more counter torque in your wrist.

Sam

[Daox]

Originally Posted by California98Civic

I lke the newer design. It'll cool itself better. Surprising the water pump turns so easily by hand.

I'm also surprised how easily the water pump spun. New pumps I've installed don't turn nearly that easily, perhaps just because they're new and not worn in yet? Old pumps usually seem corroded and also don't spin as easily either though.

Suggests that your experiement might show relatively little to be gained? How much load could an easily turned pump and its pulley be putting on the engine? Maybe the OEM pulley and its etra belt line puts as much load on the engine as the pump itself?

That is all very possible. That is one of the reasons I really want to test out the power draw at differenet OEM engine speeds before just doing the mod and saying "TADAAAA". Perhaps once it starts spinning, a reasonable load will be put on it (I'm kind of doubting that at the moment). I searched and searched before doing any of this, and never was able to find something that said "a water pump pulls X horsepower at X rpm". When I get to testing, we'll know exactly how much power it takes through the entire rpm range.

There are still other 'nice' benefits like having heat when the engine is off in winter, and cycling the pump while preheating with a block heater. But, if those are the only real benefits it really cuts down on the 'bang for the buck/time/pain in the butt' factor.

[California98Civic]

Originally Posted by Daox

...I searched and searched before doing any of this, and never was able to find something that said "a water pump pulls X horsepower at X rpm". When I get to testing, we'll know exactly how much power it takes through the entire rpm range. ...

That will be public science! A good reference point for others of us who also don't get to see such data (I guess OEM folks know). Maybe create a new thread with appropriate thread title just for that datapoint? So it stands out on web searches?

[Daox]

Thanks, and yeah thats kind of the point. It should be easy enough to do, so why not provide useful info for everyone?

[Daox]

Originally Posted by samwichse

Pierburg Cooland Pumps CWA 50 $75 - DIY Electric Car Forums

How about a cheapo all-in-one unit? Pierburg CWA 50 specs:
Voltage: 8.5 to 16 volts
Current at 12.5v : 6.5 amps
Free flow capacity: 30 liters per minute.
Capacity with 20ft head, 8.7 psi, 0.6 bar: 24 liters per minute
1/2 inch barbed ports.

How much flow rate do you need? 24L/min is a bit more than 1 gallon every 10 seconds.

That looks like a nice little pump. The problem is I have absolutely no idea what kind of flow rate I really need. Its a lot of guess work and a lot of basing things off the OEM setup at this point.

[Daox]

I have the water pump pulley printed out. It came out quite nicely. Here are some pics.

[redneck]

.

Nice...


>

[California98Civic]

How durable is that material?

[Daox]

Its ABS plastic. So its a bit more resiliant, but similar to PVC pipe material.

[oil pan 4]

I can test how much power it takes to run a coolant pump, the same way I tested power draw for power steering and vacuum pump.

The electric coolant pumps I run use well under 100 watts. But those are direct driven by their motor.