Electric Water Pump How to.

[Brian]

One thing I'll add...

These are centrifugal pumps, not positive displacement pumps. So they have a graph of head pressure/flow rate. Putting 2 pumps in series, they will share the total head. Not equally unless they're perfectly placed, but they do lower the head in the other. So running 2 in series will increase the flow of the system by lowering the head each pump sees.

 

[Howard Jones]

I found this on the Meziere Web site.

"Additional Notes: In our experience, a 20 GPM pump can cool up to approximately 250HP continuous duty. The 35 GPM pump is suitable for normally aspirated engines up to 650HP. Supercharged, Turbocharged, and high compression, high horsepower applications should use the 55GPM High Flow pump only."

So it may be that a single 50 gal/min pump will work just fine. At least from what this information seems to state.

I don't disagree, Brian. You are correct that there is an interaction between the two pumps. Here is what I based my comment on. However, some of this discussion is complicated by the fact that we are using these pumps in a closed-loop system. In our case, I believe that the term "head" may be misleading other than as it is relates to the placement of the pump inlet to the majority of the coolant level volume. Considering the effects on system pressure instead may better serve our purpose. Frankly, I would love to hear from a person with engineering experience in fluid dynamics or a more directly related field.

Pumps - Parallel vs. Serial Arrangement

Adding head and flowrate for pumps arranged in parallel vs. serial.

www.engineeringtoolbox.com

 

[Howard Jones]

Joel. I have spent a little time thinking about your question. Here my thoughts. The "head" issue is so fundamental that I think you would be best served to mount the pump as low in the chassis below the coolant volume as you practically can, Then as close as possible to the engine cool side inlet as possible. If this is a location at the rear of the front radiator mount/enclosure rather than directly into the radiator then closer is better from a design standpoint. A couple of feet would be worth doing IMHO. Inches? Not so much. Might you have a location back in the engine room but not right at the engine inlet? The effective full length of the sidepod would be worth it I think. However, don't add a lot of turns to the system or raise the pump to save a few inches in length. Straight and smooth is best but LOW in the main thing here. Overall system "head" is also improved by raising the coolant volume in relation to the pump. How? Place the header tank as high as possible. A bigger header tank with more volume is also useful.

Looking at your pictures again. If it was me I wouldn't change that very nice installation unless I found I had an issue. Really nice work. Maybe my comments would be better considered in the planning phase of a build for the next guy. But it's always a but isn't it? It has all got to fit in there somewhere and you just do the best you can.

 

[Brian]

Keeping the pump as low as possible and pumping as cool of water as possible has another big advantage.

Cooler water means the pump is running cooler and lasting longer. This and being low as possible maximizes inlet pressure and minimizes the chance of pump cavitation. Cavitation can be destructive to the pump impeller.

I'm not a PE fluid engineer, but I do have some plumbing background.

 

[Randy Folsom]

I just watched this YouTube video about the CWA400 pump (used in BMWs). He makes a pretty good argument that this pump is better than the either the Meziere and Davies Craig offerings. Hoping those with more experience can weigh in. Thx much.

https://youtu.be/atLzbKPMnnU?si=2mIUlweBzoNBi4W3

 

[Brian Kissel]

That is the pump Scott is talking about in post 5. I am also going to be using one in my Lola.

Regards Brian

 

[Randy Folsom]

I bought the CWA-400 on Amazon. It was on sale so the decision made itself. Now I need to figure out which fittings I need. I was thinking to use a gutted mechanical pump for the inlets, but wondering if fittings might be more efficient. A gutted mechanical pump can be done for a fraction of the cost compared to fittings. My question is, ‘are fittings worth it?’ This is for a 530 HP 302/363 that will primarily be driven on the street, but will also hopefully see some spirited track days.

 

[Howard Jones]

I found some specifications for the Pierburg 400. It's interesting that it has a flow rate of approx 44 gal/min. So I think we are really zeroing in on how much flow rate is needed. That's right in line with all of the three pumps mentioned above. 40-60 Gal/min seems to be the range.

HOWEVER : Note the power requirement. 12.5VDC @ 36 amps.

Pierburg CWA-400 HX Coolant Pump Kit w. Pigtail

Pierburg CWA-400 HX Coolant Pump Kit w. Wiring Harness (CWA400)

www.montmotorsports.com

https://www.tecomotive.com/download/datasheets/CWA400_EN.pdf

 

[Howard Jones]

Randy. That is always the question I suppose. Easy and cheap but kind of a hack, extravagant and expensive, Or take a little time and make something yourself that is not expensive but elegant.

 

[Neil]

I found some specifications for the Pierburg 400. It's interesting that it has a flow rate of approx 44 gal/min. So I think we are really zeroing in on how much flow rate is needed. That's right in line with all of the three pumps mentioned above. 40-60 Gal/min seems to be the range.

HOWEVER : Note the power requirement. 12.5VDC @ 36 amps.

Pierburg CWA-400 HX Coolant Pump Kit w. Pigtail

Pierburg CWA-400 HX Coolant Pump Kit w. Wiring Harness (CWA400)

www.montmotorsports.com

https://www.tecomotive.com/download/datasheets/CWA400_EN.pdf

One needs to be leery of the flow rating of pumps. Without a corresponding back pressure spec, it is probably just "free-flow" an unrealistic specification in an actual application. Pumps should be specified with a flow vs back pressure curve.

 

[Randy Folsom]

I found some specifications for the Pierburg 400. It's interesting that it has a flow rate of approx 44 gal/min. So I think we are really zeroing in on how much flow rate is needed. That's right in line with all of the three pumps mentioned above. 40-60 Gal/min seems to be the range.

HOWEVER : Note the power requirement. 12.5VDC @ 36 amps.

Pierburg CWA-400 HX Coolant Pump Kit w. Pigtail

Pierburg CWA-400 HX Coolant Pump Kit w. Wiring Harness (CWA400)

www.montmotorsports.com

https://www.tecomotive.com/download/datasheets/CWA400_EN.pdf

Howard, I think the Pierburg CWA-400 flow rate is measure at 8 PSI and the others are measuring without referencing any pressure so assume it is zero. I am going to guess the 36amps is at full max pressure/flow. Hoping that will not be the case in actual use. My pump will be delivered in a few days. I am also picking up a partially completed Factory Five Mk2 Cobra in a few days. I will see if I can install the Pierburg just for testing and a real world electrical load. Cheers, Randy

 

[Randy Folsom]

Anybody have an extra Tecomotive "tinyCWA" pump controller they want to sell? Their website says that it will be at least 90 days to fill an order. Hoping for alternative recommendations.

 

[Brian]

Have you ever programmed an Aurduino?

 

[Randy Folsom]

Have you ever programmed an Aurduino?

I have programmed a Raspberry Pi and followed instructions for setting an Arduino for a CNC router. If there is a guide, I can probably figure it out.

 

[Brian]

Sounds like a perfect little micro-controller project. Read temp sensor, adjust PWM that controls pump to a mapped value. You could add 4 or 6 LEDs that make a bar graph displaying the PWM demand.

Should be a simple little bit of code. Arduino is way overkill, but cheap and readily available, and it has a on board regulator so you can feed it 12V. A few resistors and to be safe a 4.9V zeneer diode to protect the board and you're good.

The Nano is my fav as it has a built in usb and com chip.

https://www.ebay.com/itm/355027145190

Or you could go fancy and get one with an OLED display if you want to wander deeper into it and display some status.

Nano V3 Board ATmega328P CH340 Controller with 0.91'' OLED Display for Arduino | eBay

New version driver CH340 Replace FT232RL.

www.ebay.com

 

[Randy Folsom]

Sounds like a perfect little micro-controller project. Read temp sensor, adjust PWM that controls pump to a mapped value. You could add 4 or 6 LEDs that make a bar graph displaying the PWM demand.

Should be a simple little bit of code. Arduino is way overkill, but cheap and readily available, and it has a on board regulator so you can feed it 12V. A few resistors and to be safe a 4.9V zeneer diode to protect the board and you're good.

The Nano is my fav as it has a built in usb and com chip.

https://www.ebay.com/itm/355027145190

Or you could go fancy and get one with an OLED display if you want to wander deeper into it and display some status.

Nano V3 Board ATmega328P CH340 Controller with 0.91'' OLED Display for Arduino | eBay

New version driver CH340 Replace FT232RL.

www.ebay.com

Might as well give it a try. My understanding is that the CWA-400 pump has a built in controller, so just need to feed it signal data.

 

[Brian]

I'm not familiar with it, but I think it just needs a PWM signal, and the Arduino can output a 400 some odd hz PWM, Should work.

You'll need to map the temp sensor. They're usually a thermister to ground. Add a resistor to the 5v and see where the resulting voltage is at 180 deg and 220 deg and have it ramp from 20-100% over that or what you think is appropriate.

For safety, you may want to add a small NPN transistor and resistor to buffer the microcontroller output.

 

[Howard Jones]

Randy, I was thinking I had planned to do an electric pump in my GT40 a long time ago and I had started on making a water pump that had the bearing cartridge pushed out of it. Well, I went out to the shop and found it. I had also cut off the snout and welded a plate over the hole so basically it is ready to use. It's a aftermarket USA passenger side inlet for a SBF. I have no need for it so if you want it let me know. Free homemade fraction of zero elegance!!!!! I'll post a picture or two when I get back out there later.

 

[Randy V]

Randy, I was thinking I had planned to do an electric pump in my GT40 a long time ago and I had started on making a water pump that had the bearing cartridge pushed out of it. Well, I went out to the shop and found it. I had also cut off the snout and welded a plate over the hole so basically it is ready to use. It's a aftermarket USA passenger side inlet for a SBF. I have no need for it so if you want it let me know. Free homemade fraction of zero elegance!!!!! I'll post a picture or two when I get back out there later.

I did the same for my GT. It was the perfect manifold to mimic the factory water pump and distribution..

 

[Randy Folsom]

Might as well give it a try. My understanding is that the CWA-400 pump has a built in controller, so just need to feed it signal data.

Looks like someone figured out how to do it. Unfortunately, no info

Randy, I was thinking I had planned to do an electric pump in my GT40 a long time ago and I had started on making a water pump that had the bearing cartridge pushed out of it. Well, I went out to the shop and found it. I had also cut off the snout and welded a plate over the hole so basically it is ready to use. It's a aftermarket USA passenger side inlet for a SBF. I have no need for it so if you want it let me know. Free homemade fraction of zero elegance!!!!! I'll post a picture or two when I get back out there later.

Yes please. How much? I will gladly pay shipping.