Electric or mechanical water pump?

[Pat]

Sorry for all the questions but still trying to work out my front accessories before I pull the plug on them. Trying to decide on electric or mechanical water pump. Electrical water pump has the disadvantage of a lot more failure points and more complicated routing system but more space up front and better cooling at idle/lower rpm’s. What’s the consensus with these cars or general opinion? Looking for advice from those who have gone down this road. Not worried about what’s easier to install or what they got away with 55 years ago but what actually works better for street with a once a year fun track day. Car is an RCR with Dart 302 block stroked to 363 (520hp).

Thanks!
Pat

 

[Brian Kissel]

Good question Pat. I’m interested as well. I have already purchased a electric pump, but my build is some time away. Interested in the consensus.
Thanks for posting !!
Regards Brian

 

[Ian Anderson]

Post in thread 'Electric Water Pump question'

Jun 21, 2015

Re: Electric Water Pump running too cool

All, I plugged the rear cylinder head bleed outlet with little or no effect, still drops down to 50C 122F on motorway. Holds a steady temp just above the set point of 85C at idle when stationary. I have checked the heater and there is no hot water going through it, not surprising since there is no mech pump differential pressure any more and the heater valve is closed anyway. There are no other circuits, so unless I have missed something, the only answer is the circuit resistance is lower than the pump controller can handle or there is a...

• wolodymyr

Ask and it has been done

Ian

 

[Brian Kissel]

Ian. Thanks for posting that. I’m still in the hospital and having issues seeing all the information on my phone. If I get home, I’ll open it on my PC where I can see it better. I think I Remember Howard posted about his race car. His issue was overheating. So between the two posts I should have some excellent information on both ends of the spectrum . I’m pretty sure my issue will be overheating as I have a aluminum Brodix BBC coming for my Lola. I appreciate all the information you guys post and try to keep a file on it.

Regards Brian

 

[Randy Folsom]

Sorry for all the questions but still trying to work out my front accessories before I pull the plug on them. Trying to decide on electric or mechanical water pump. Electrical water pump has the disadvantage of a lot more failure points and more complicated routing system but more space up front and better cooling at idle/lower rpm’s. What’s the consensus with these cars or general opinion? Looking for advice from those who have gone down this road. Not worried about what’s easier to install or what they got away with 55 years ago but what actually works better for street with a once a year fun track day. Car is an RCR with Dart 302 block stroked to 363 (520hp).

Thanks!
Pat

Pat,

I have a very similar engine from Prestige. I plan to go with a Pierburg 400 electric water pump and the Tiny CWA controller from Tecomotive. Links below.

Howard recommended placing the pump as low as possible and as close to the engine as possible. I am going mount it inside the tub surround below the four link mount. It will be relatively easy to access via the lower bulkhead access panel. It seems the issues with trapped air are pretty much the same as mechanical pumps. The benefits that I want to take advantage of are improved power at higher RPMs and improved cooling at low RPMs.

I hope to complete the installation and do a test run by the end of September.

This is why I chose the Pierburg

Cheers, Randy

https://a.co/d/eVdbhXg

Tecomotive - tinyCWA

Tecomotive develops and sells unique electronic devices for use in vehicles of all kinds.

tecomotive.com

 

[Ryan L]

I am planning to go electric.
my reasons are

• works efficiently over a boarder engine rev range
• less load on start-up when oil pressure is lower.
• less coolant cavitation at high rpm so less air and steam will be created in the system and more stable cooling
• lower center of gravity
• more clearance at the front of the engine, and less of a bulge in the fire wall, I am tall so i am hopeful that this improves cabin comfort.

 

[Neil]

Pat,

I have a very similar engine from Prestige. I plan to go with a Pierburg 400 electric water pump and the Tiny CWA controller from Tecomotive. Links below.

Howard recommended placing the pump as low as possible and as close to the engine as possible. I am going mount it inside the tub surround below the four link mount. It will be relatively easy to access via the lower bulkhead access panel. It seems the issues with trapped air are pretty much the same as mechanical pumps. The benefits that I want to take advantage of are improved power at higher RPMs and improved cooling at low RPMs.

I hope to complete the installation and do a test run by the end of September.

This is why I chose the Pierburg

Cheers, Randy

https://a.co/d/eVdbhXg

Tecomotive - tinyCWA

Tecomotive develops and sells unique electronic devices for use in vehicles of all kinds.

tecomotive.com

This looks like a nice electric water pump but the lookup table controller is not the way I would do it (it's the design engineer in me). A pot that sets a desired coolant temperature, a coolant temperature sensor, and a PID controller with a PWM output would be my choice, Set the pot to the desired temperature and the system holds the coolant temperature to that set value= no need to fool around juggling duty cycle, it is automatic.

 

[Randy Folsom]

This looks like a nice electric water pump but the lookup table controller is not the way I would do it (it's the design engineer in me). A pot that sets a desired coolant temperature, a coolant temperature sensor, and a PID controller with a PWM output would be my choice, Set the pot to the desired temperature and the system holds the coolant temperature to that set value= no need to fool around juggling duty cycle, it is automatic.

Neil, thx for the input. Which PID controller do you recommend? Cheers, Randy

 

[Neil]

Neil, thx for the input. Which PID controller do you recommend? Cheers, Randy

If it were my project, I would design my own PID controller & PWM driver. I haven't followed the market as to what is available but a good system will be dependent on the sensor temperature/resistance slope and the thermal time constant of the coolant system. It is an engineering challenge...

 

[Randy Folsom]

If it were my project, I would design my own PID controller & PWM driver. I haven't followed the market as to what is available but a good system will be dependent on the sensor temperature/resistance slope and the thermal time constant of the coolant system. It is an engineering challenge...

Neil, I think your description matches up nicely with the Tecomotive. It uses a short temp history to proactively reduce flow if the temp is dropping and increase flow if rising. I plan to wire it such that it will continue to operate after the ignition is turned off. Same circuit as the radiator fans. Cheers, Randy

 

[Chris]

I am so pleased I went with a Davies Craig Electric Water Pump. Having run V8's all my life, when building my GT40 was my first go with an EWP. What a tool. Really keeps the engine cool and if I get stuck in traffic and I turn the engine off it cools it rather than getting hotter (which is what my Cobra does!)
I have had a couple of issues, failed digital controller (really good customer service to replace via T5 Designs) and a broken casing bolt but the latter might have been my fault!!!!
In terms of performance it is very good indeed. I would not hesitate to use another one, in fact, I might try one on the cobra.

 

[Walter]

My car has both ;-) Modified (as there is no heater circuit from the pump) LS7 water pump plus electric unit in the radiator circuit. The latter runs on (thermostatically controlled) after engine shut down.

 

[Paul Proefrock]

Randy,
Is there a thread on how you chose the CWA400 over the 200 or 150. Is bigger better when you use an electric pump? Can they be oversized?

Paul

 

[Brian Kissel]

Paul, reading their website, the 400 is designed for V8’s. That is what I purchased as well. I purchased directly from them in Germany because there are so many cheap knockoff s out there. I think I read that in Scott’s build log. He does NOTHING half assed and goes into detail why he made the choice of parts that he did . I am in the states and shipping was not bad. It might have been free, I don’t remember. If I remember correctly, Prestige told me I didn’t need a controller and I could run it wide open and let the thermostat control it. I would still need to have it run after shutdown, to cool it. The Dominator ECU should be able to handle that however. I plan to be able to run it with heaters to preheat the engine prior to starting it. I will also have a heater in my oil pan and will run a pump that will run hot oil through the engine prior to starting. Hoping to help stabilize the temperature of the engine to prevent “cold startup”. These pumps are extremely useful. You can’t do that with a mechanical pump.

Regards Brian

 

[Brian Kissel]

I’m on my phone and struggling to find exactly what I’m looking for, but here is a link to Swartz’s Garage. This isn’t the exact detail that I am looking for, but once you are there, the water pump is partially discussed near the bottom of the page. I would suggest anyone and everyone subscribe to his build. His build is just a little bit higher than the next level. He discusses why he does what he does.

Cooling, Heating and A/C — Swartz Garage

www.swartzgarage.com

Regards Brian

 

[H.J.Bayer]

@Randy
Thanks for the tip about the Pierburg 400, the Tiny CWA controller and the Tecomotive website! I didn't even have that on my screen, the good things are often so close...

@brian
Thanks for the link to Swartz's Garage, I registered right away.
But what the hell is a coolant swirl pot?
I haven't seen that yet.
can someone explain how it works and maybe show me an example picture?

 

[Paul Hendrickx]

@Randy
Thanks for the tip about the Pierburg 400, the Tiny CWA controller and the Tecomotive website! I didn't even have that on my screen, the good things are often so close...

@brian
Thanks for the link to Swartz's Garage, I registered right away.
But what the hell is a coolant swirl pot?
I haven't seen that yet.
can someone explain how it works and maybe show me an example picture?

Swirl Pot - Coolant Deaeration Chamber

Product Design,SolidWorks,Keyshot

www.behance.net

Well explained,
greetings from France
Paul

 

[Paul Hendrickx]

 

[Paul Hendrickx]

View attachment 140789

 

[H.J.Bayer]

Wow Paul,
Thanks for the great explanation!
I always like to keep things as simple as possible. Of course, the combination of swirlpot and expansion tank from Concept Racing would be ideal.
In my car, it's all about engine cooling, I don't have heating or air conditioning.
If I understand everything correctly, such a combination swirlpot would be sufficient, e.g. on the firewall, without any further opening in the cooling circuit. Possibly another bleeder screw at the front of the radiator for filling.

The system could look like this:
Engine water outlet -> electric water pump -> up to the swirlpot -> down to the radiator -> back to the engine.

that sounds almost too simple now...