Electric Water Pump Conversion

General discussion about our beloved Tercel 4WD cars
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Kozuto_98
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My tercel:: 1987 SR5 Wagon
Location: Nova Scotia, Canada

Electric Water Pump Conversion

Post by Kozuto_98 »

Howdy everyone!

My apologies for the last few months of inactivity, life loves to throw curve balls when you least expect.

A month or so ago I had gone through my Tercel's cooling system and replaced things like the pump, thermostat, tubing, and gaskets in
an effort to track down a small coolant leak. The new pump that came with the car when I bought it turned out to be kind of a dud, as in
it really does not like the impeller being moved, which has caused some heat troubles.
I think the "new" pump had been sitting for too long, I don't really know...
To top that off, in my ever growing wisdom I bought a thermostat for a 3rd gen Tercel, which fits but seems to have a different temp point to open.

Before I continue I will point out all the work I plan to do for this project is entirely experimental and I would not suggest doing this unless
it ends up working well.

Here is the list of parts I needed to make this all work:
Bosch 0392022010 Water Pump (meant for Mercedes-Benz models)
DNA Motoring Honda D & B series dual core aluminum radiator (I'm trying this just to see if it works well or fits)
Twilight Garage 12V Universal Pusher Fan
Yeepin 32MM Inline Temperature Sensor Adapter
2X HPS Performance 22MM - 32MM silicone reducer (because the pump outlets are 22MM)
2X HPS Performance 32MM aluminum 4 inch jointer

That covers all the stuff I'd need for the engine side. Everything except the parts from HPS I picked up on Amazon.

To control all the pump and fan, and also take temp readings I decided to go for the Arduino platform.
Here are the parts I needed to make this work:
Elegoo Arduino Nano
COVVY 2 Channel Relay Module
Cylewet DS18B20 Waterproof Temperature Sensor
4.7K Ohm Resistor
IZOKEE B-Y-B 128x64 OLED Display
DROK 5V Buck Converter

I also picked up some weather proof connectors, a 12 pin bulkhead connector, and some plastic project boxes.

The first order of business was programming the Arduino to make everything work.
What I'm doing is taking a reading in celsius from the temp sensor, checking if it's above a given temp, and turning the fan on if
the temp condition is met. I will post my code on Github later on for those interested.
The display is acting as a temp gauge and also a way to make sure the fan is turning on.

So far I have put together all the controller related parts, plus some wiring. I have yet to put everything together in
the Tercel.

I will update this post more once things start going together.

Let me know what you think, I'd love to hear some feedback and input!
Last edited by Kozuto_98 on Sat Feb 20, 2021 8:23 pm, edited 3 times in total.
1987 Tercel Wagon SR5 4WD
1997 Acura CL
RIP 2016 Civic (wrist pin recall)
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Kozuto_98
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My tercel:: 1987 SR5 Wagon
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Re: Electric Water Pump Conversion

Post by Kozuto_98 »

Here's a link the the Github gist for the Arduino code
https://gist.github.com/Kozuto98/411cd6 ... 2c29c2414c

I'll post a wiring diagram for the work once I have more stuff done to this project!
1987 Tercel Wagon SR5 4WD
1997 Acura CL
RIP 2016 Civic (wrist pin recall)
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Kozuto_98
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Re: Electric Water Pump Conversion

Post by Kozuto_98 »

new car wiring.png
Here is the current wiring diagram I am working off of to make this all work.
This may be subject to change.

Here's the rundown of everything and where it's connected to.

From car
12V Switched Main: Voltage in (buck converter)
Ground Common: (buck converter, radiator fan, water pump)

Buck Converter
Voltage In: 12V Switched Main
Ground: Ground Common
USB: Micro USB (Arduino Nano)

Arduino Nano
A4: SDA (display)
A5: SCL (display)
5V: 5V (display, relay module, temp sensor)
GRN: GRN (display, relay module, temp sensor)
4: Data (Yellow) on temp sensor
11: R1 (relay module)
12: R2 (relay module)

Display:
GRN: GRN (Arduino Nano)
5V: 5V (Arduino Nano)
SCL: A5 (Arduino Nano)
SDA: A4 (Arduino Nano)

Relay Module
Channel 1 & 2 In: 12V Switched Main
Channel 1 Out: Water Pump
Channel 2 Out: Radiator Fan
GRN: GRN (Arduino Nano)
R1: 11 (Arduino Nano)
R2: 12 (Arduino Nano)
5V: 5V (Arduino Nano)

Temp Sensor
BLACK: GRN (Arduino Nano)
YELLOW: 4 (Arduino Nano) + 4.7K Ohm Resistor
RED: 5V (Arduino Nano)

Radiator Fan
BLACK: Ground common
GREEN: Channel 2 Out (relay module)

Water Pump
BLACK: Ground Common
GREY: Channel 1 Out (relay module)

Sorry if my diagram is confusing. I'll have pictures of the actual wiring when I start doing the work!
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1987 Tercel Wagon SR5 4WD
1997 Acura CL
RIP 2016 Civic (wrist pin recall)
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Kozuto_98
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Re: Electric Water Pump Conversion

Post by Kozuto_98 »

Here's another quick update to this conversion project.

Because the original belt driven pump is no longer needed I was looking for ways to make a blank piece to cover where the pump was.
At first I was going to either just leave the pump in place and not connect it to a belt, or have the impeller in the pump removed.
But as it turns out MRP sells a blank plate for 4A-GE motors, and it seems to match up with the 3A-C pump gasket, so I'll be using one of these.
https://www.mrpltd.co.nz/product/4age-water-pump-blank/
1987 Tercel Wagon SR5 4WD
1997 Acura CL
RIP 2016 Civic (wrist pin recall)
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NWMO
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Re: Electric Water Pump Conversion

Post by NWMO »

Very interesting Kozuto. I have typically been pleased with the stock cooling set-up and even heater after servicing. I will have to see how it does in the morning (-10 F), forecast even colder for Tuesday morning.

Chris
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Kozuto_98
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Re: Electric Water Pump Conversion

Post by Kozuto_98 »

I'm honestly really impressed with how well the heater works in these.
Minus heated seats, once the engine is all warmed up it pumps out more heat than my 2016 Civic.
1987 Tercel Wagon SR5 4WD
1997 Acura CL
RIP 2016 Civic (wrist pin recall)
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Petros
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Re: Electric Water Pump Conversion

Post by Petros »

the electric water pump, much like the electric power steering pump, seem like an interesting idea in terms that is it supposed to reduce the draw on the engine, making the power available to the flywheel, or improved economy.

What I find a bit puzzling is that the power needed to drive these pumps will be drawn effectively from the alternator, which means that more power is needed to drive the alternator. so you go from a mechanically belt driven pump, to a electrically driven pump that draw power from a mechanically belt driven alternator. How does that save total power draw? in fact you will have more losses, the belt loss, plus the alternator loss, plus the electric motor loss.

Also, the mechanical pump is a very simple and reliable set up that lasts a very long time, than you go to a complex multi step operation that has multi modes of failure. Why do it? what benefit will you gain? if working properly, the stock cooling system works fairly well, a larger radiator would all that is needed if you want to push more power through the engine with extensive modes or an engine swap.

There are perhaps better more efficient belt and pulley designs that can be adapted to the stock water pump, and you can greatly improve the efficiency of the water pump with polishing and enlarging the passage ways, like porting the intake passages in the head. when I worked for a professional racing team there was a similar "conventional" thought of adapting a larger pump to the racing engine to get more cooling flow, which would have been very difficult to do. but I had suggested that we just modify the stock Nissan water pump and bench test it to see how much we can improve the flow. After some experimenting and trail and error, we almost doubled the flow capacity of the stock water pump using the same housing, with conventional porting and polishing, and an improved the impeller design that was the same diameter. That water pump became a performance water pump that was sold for racing on Nissan engines.

but unless you are putting in a 200 hp+ engine, I do not see the need to "improve" the cooling system in such a complicated way.

What is it you hope to achieve? other than having a kind of interesting alternative system to show around, which I have to admit is an interesting idea.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
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Kozuto_98
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Re: Electric Water Pump Conversion

Post by Kozuto_98 »

The electric pump is mostly just for an experiment.

I had some similar thoughts on the extra load the alternator will have driving the pump. My best guess / hope is the gain from not driving the
pump from a belt would balance out the added alternator load.

Another reason I conjured this idea up was if there comes a day when new pumps for these Tercels become less available, there will be
something else to go on. I can't really see that happening though.

If the conversion doesn't end up working out well, I can always go back to a factory pump.
1987 Tercel Wagon SR5 4WD
1997 Acura CL
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The Professor
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Re: Electric Water Pump Conversion

Post by The Professor »

Petros wrote: Tue Feb 16, 2021 12:03 amWhat I find a bit puzzling is that the power needed to drive these pumps will be drawn effectively from the alternator, which means that more power is needed to drive the alternator. so you go from a mechanically belt driven pump, to a electrically driven pump that draw power from a mechanically belt driven alternator. How does that save total power draw? in fact you will have more losses, the belt loss, plus the alternator loss, plus the electric motor loss.

Also, the mechanical pump is a very simple and reliable set up that lasts a very long time, than you go to a complex multi step operation that has multi modes of failure. Why do it? what benefit will you gain?
We're moving to electrified accessories on the vehicles we build at work, and across the board, this is becoming the new normal.

It takes less energy to spin the alternator and power the accessory than it does to run it off the FEAD (front engine accessory drive). You save rotational inertia from the now-electric accessory, less friction from running fewer FEAD pullies, a less cluttered engine bay, and all that rolls up into better fuel economy and lower emissions. That's what you gain.

I'm not the design engineer for our electrified accessories so I can't provide specific numbers, but the entire automotive industry is moving towards electrified accessories, and electrification in general, because it is more efficient.
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Re: Electric Water Pump Conversion

Post by Petros »

The Professor wrote: Tue Feb 16, 2021 2:36 pm ...the entire automotive industry is moving towards electrified accessories, and electrification in general, because it is more efficient.
yes, I noticed that is the current trend in new cars. the V-belt drive has a lot of friction and I can see changing that to a cog belt or some other design, but the alternator is still belt driven, so the efficiency savings seems small. each conversion you go through from mechanical energy, to electrical energy, than back into mechanical energy for the pump always costs you efficiency. so it is difficult to see how it would save much. overall it might save some weight perhaps, but that seems like a costly way to save weight. I guess the wizards of smart at the large companies have worked it out. I am not convinced that overall it will save much, especially if the system is more prone to break downs.

I know much of it is driven by government regulations, so the manufacturers are doing what they must to meet government mandates, rather than actually make it a better design. one reason why I just as soon stay with the older cars that are mostly regulation free. I have a client who builds hot rods from chassis kits, and somehow gets it registered as a classic "restoration", and is exempt from all regulations, he does not even have to have seat belts. but there is nothing original about his builds: 4 wheel disk brakes, all aluminum fuel injected and blown v-8. it gives me ideas....
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
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Kozuto_98
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Re: Electric Water Pump Conversion

Post by Kozuto_98 »

Just a little progress update.
Got all the boards setup in project boxes with some connectors and wiring to them.
I'll have everything all hooked up once i get my engine donor car out of the garage.
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Re: Electric Water Pump Conversion

Post by splatterdog »

I'm with Petros on this. Rock simple and it's inherent reliability is a huge part of what appeals to me with these cars. In 25 years of T4'ing I've had only one pump failure. As long as the engine runs, it cools. To me, Kozuto is fixing a problem that doesn't exist. But I can appreciate the ingenuity it takes for a project like this.

Kozuto- Will the pump be pulse width modulated or on/off? If the pump is PWM it may not like full on. How about an after run of pump and fan during high temps to reduce heat soaking? My experience with Euro electric water pumps is that they are only auxiliary, do they have comparable flow to a mechanical?

Keep in mind that if your head gasket fails anytime after this Petros will give you a big I told you so. haha
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Kozuto_98
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Re: Electric Water Pump Conversion

Post by Kozuto_98 »

splatterdog wrote: Wed Feb 17, 2021 9:12 am I'm with Petros on this. Rock simple and it's inherent reliability is a huge part of what appeals to me with these cars. In 25 years of T4'ing I've had only one pump failure. As long as the engine runs, it cools. To me, Kozuto is fixing a problem that doesn't exist. But I can appreciate the ingenuity it takes for a project like this.

Kozuto- Will the pump be pulse width modulated or on/off? If the pump is PWM it may not like full on. How about an after run of pump and fan during high temps to reduce heat soaking? My experience with Euro electric water pumps is that they are only auxiliary, do they have comparable flow to a mechanical?

Keep in mind that if your head gasket fails anytime after this Petros will give you a big I told you so. haha
The pump is a simple on / off deal. I was hoping to get a full PWM pump so I could have some flow control at lower rpm but the cost
was a bit too high. The Bosch pump I ordered can flow 1400 L/h (23.34 L/m) so it should be fine.
I haven't been able to fine an answer to what the average flow rate of the stock Tercel pump is so I don't really have anything to compare those
numbers to.
1987 Tercel Wagon SR5 4WD
1997 Acura CL
RIP 2016 Civic (wrist pin recall)
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Kozuto_98
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Re: Electric Water Pump Conversion

Post by Kozuto_98 »

Thought I should leave a little update on this project.

For now I'm retaining the factory pump. What I ended up doing was using the water pump from the 4A-FE I have torn apart and putting it in
the 3A-C in my Tercel. Also put the old thermostat back in, put new seals on everything, put the DNA Honda D series dual core aluminum radiator
and fan combo in. I discovered that the tube coming from the top outlet had an o-ring that had basically turned into powder so I replaced that
with one that fit from an o-ring set I had laying around.

The new radiator works really good. I can tell whenever the thermostat opens because the temp needle drops really fast, so color me impressed.

I'm also going to replace the head gasket and head bolts in a week or so because I most likely have some damage to the one in the engine after
running it on the hot side for a month or so. I ordered a felpro one and I'm curios as to if I should copper spray it. I've done this on some low boost
Honda stuff before, but I'm not sure if it'll be all that necessary.

The 4A-FE pump and having the old thermostat made a big difference. The "new" water pump that was given to me when I bought the car was
frozen stuck when I pulled it out so that explains the problem. I also compared the new and old thermostats and they were indeed different.
The new thermostat was meant for a 1987 Tercel with the 3E-E. (Gen 3 Tercel)
It fits but opens at a higher temp. That was my mistake when ordering the part.

I'll still try the electric pump in the future, but for now I'll leave everything as is.

I also bypassed the EGR tube going to the carb hat and it made quite a difference to engine response. It may just be me, but my butt dyno could
feel a difference.
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1997 Acura CL
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Re: Electric Water Pump Conversion

Post by Mark »

When I replaced the head gasket on my '81 a year or so ago, I copper sprayed it. It's probably not manufacturer recommended, but the original head gasket failed not at the cylinder seals, but it allowed a small external coolant leak under the exhaust manifold. I was hoping the copper spray would provide a slightly more reliable seal with the aftermarket new head gasket around the oil/coolant ports. I'm not sure if there are any concerns with electrolysis with the copper and the aluminum/steel engine. I don't think so as long as you're not running tap water in the coolant system.
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