Lotus Elan

Davies Craig Electric Water Pump Setup

PostPost by: Rokkbert » Wed Jul 27, 2022 5:44 pm

Hi all,

After using this forum for years, pulling from the seemingly endless pit of expertise, I felt it was finally time for me to give back.

While going through the process of installing an electric water-pump from Davies Craig, I noticed much of the information on this forum is either vague or incomplete. There seem to be a lot of mixed accounts and misinformation around both the installation of the kit, as well as the viability of an electric water-pump as a whole.

Because of this, I felt that perhaps some users on here would like a first hand account of the installation process, coming from someone who is currently running this pump with much success.

For clarification, this is in a Federal +2, and utilizes the water-pump with the included wiring harness and controller. I can confirm that this setup works very well in my car, however Loti seem to have a lot of… character, and your milage may vary.

The main headache of this installation was the discreet location of the pump. Because of the lack of space, I felt that the area below the front carb was my best bet. Using a section of the original lower-rad-hose, as well as a couple of 90 degree bends, I was able to place the pump JUST out of the way of the distributor. The orientation of the pump was also a concern of mine, as the pump wants to be upright in order to bleed air effectively out of the system.

One of the reoccurring criticisms of this modification is the belief that you will lose the use of your heater. If the stock heater return location is used, then this concern is absolutely valid. The issue can be easily resolved by T-ing in the heater hose before the electric pump, and capping off the old inlet on the timing cover.

I chose to leave the stock water pump in place, as it still allows coolant to pass through it, even without the impeller moving. I did, however, remove the thermostat, as it is no longer necessary for modulating the temperature.

The Davies Craig controller uses a single temperature sensor to read the coolant temperature and modify the pump’s behaviour accordingly. Because the kit comes with a fitting for said sensor, it was easy to plumb it in between the thermostat housing and the rad. Quick note: DO NOT shorten the wire running to the sensor. If you have extra wire, just bundle it up and tuck it away.

The rest of the wiring is pretty straight forward; 12v switched from the ignition switch, 12v fused from the solenoid, earth to earth, pump to pump. The controller has the ability to control an electric fan via a relay, which you’ll be happy to know works great with the stock fan.

Lastly, I hid the controller in the glovebox and ran the wiring out the back via a small hole. Looks clean and means you don’t have to look at it the whole time. The pump test light, which tells you if there's an issue with the system, I wired in behind one of the stock dash lights to keep it discreet.

A couple of final notes:

I know you can run the pump without the controller as an "always on" situation, but I would advise against this. When set up correctly the controller works incredibly well, and allows the engine to warm up and maintain temperature as it is supposed to.

It appears to me that the controller does not like to have its 12v battery power switched on and off. This may be a problem if you use a battery shutoff frequently. This hasn’t caused any permanent issues, however I have had a couple instances of the controller not activating even after the battery has been reconnected.

Thanks again to all the incredible people on this forum, without you, I highly doubt I would have a running and driving car

Cheers, and follow me on Instagram @margosfast if you wanna check out the car!
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- Robert

'69 Elan Plus 2
Is it still a barn find if it’s your barn?

@margosfast on instagram
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PostPost by: TBG » Wed Jul 27, 2022 9:15 pm

All jolly good stuff - but what is wrong with the original water pump? Works perfectly well for many many years if you know how to look after it. D
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PostPost by: Rokkbert » Wed Jul 27, 2022 9:53 pm

TBG wrote:All jolly good stuff - but what is wrong with the original water pump? Works perfectly well for many many years if you know how to look after it. D


I had a failure of my water pump so I figured, if I’m going to be tearing the whole thing apart, I might as well replace it with something I have more control over. The nice thing with the electric pump is its ability to flow a maximum of 80L/min of coolant, regardless of engine RPM. This way, when I’m stuck in traffic, I know the pump is doing everything it can to keep the engine temp within tolerance.

Plus old cars with hidden modern tech are cool 8)
- Robert

'69 Elan Plus 2
Is it still a barn find if it’s your barn?

@margosfast on instagram
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PostPost by: Frogelan » Thu Jul 28, 2022 6:37 am

Hi Robert

All improvements are worth sharing - no one is forced to implement them!

Is there a particular model of Davies Craig electric water pump that you recommend?
Could we also have some photos of your installation (not shown on Instagram) by any chance?

Andrew
1965 Lotus Elan S2 26/4022 (originally Dutchess Lotus East, PA and NJ Area, USA)
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PostPost by: Rokkbert » Fri Jul 29, 2022 6:29 pm

Frogelan wrote:Hi Robert

All improvements are worth sharing - no one is forced to implement them!

Is there a particular model of Davies Craig electric water pump that you recommend?
Could we also have some photos of your installation (not shown on Instagram) by any chance?

Andrew


The pump kit I went for is the Davies Craig EWP80 Combo. Combo basically just means it comes with the pump, controller, wiring harness, and all the little extras as well. Nice and small, but still flows a lot of coolant.

I’ll try to grab a photo tonight but I have to say, with the intake and carbs on it is VERY tight down there haha.
- Robert

'69 Elan Plus 2
Is it still a barn find if it’s your barn?

@margosfast on instagram
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PostPost by: Frogelan » Fri Jul 29, 2022 7:06 pm

Thank you for that. It is indeed a shame that it is hidden.

You could in effect spin a wonderful yarn at your local car and coffee / pub car park that it is the latest WRC turbo etc!
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PostPost by: Rokkbert » Mon Aug 01, 2022 3:40 am

Frogelan wrote:Thank you for that. It is indeed a shame that it is hidden.

You could in effect spin a wonderful yarn at your local car and coffee / pub car park that it is the latest WRC turbo etc!


Haha I like that! Boys use forced air induction, men use forced coolant induction!

Here are some photos of the pump set-up in the car. A little difficult to see the hose pathway and pump location, but hopefully my illustration helps with that.
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IMG_0703 Large.jpeg and
- Robert

'69 Elan Plus 2
Is it still a barn find if it’s your barn?

@margosfast on instagram
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PostPost by: bitsobrits » Mon Aug 01, 2022 8:10 pm

Seems it would be better to remove the stock impeller for improved flow.
Steve

Elan S1 1963-Bourne bodied
Elan S3 1967 FHC pre airflow

Formerly:
Elan S1 1964
Elan S3 1966 FHC pre airflow
Elan S3 1967 FHC airflow
Elan S4 1969 FHC
Europa S2 1970
Esprit S2 1979
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PostPost by: alaric » Wed Aug 10, 2022 9:58 pm

Hi.

Thanks for your post on this. It's certainly something that I will look at doing at some point. If the pump is able to deliver higher water flow rate through the radiator than the mechanical one, the amount of energy that can be removed by the system should be increased, as the radiator should be hotter. This may be simpler and more effective than fitting a larger radiator. You don't mention it getting hotter when when cruising at speed, so it must be delivering at least as much flow as the mechanical pump at higher revs. Thanks for the write up.

Regards.

Sean.
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PostPost by: Rokkbert » Wed Aug 10, 2022 11:27 pm

alaric wrote:Hi.

Thanks for your post on this. It's certainly something that I will look at doing at some point. If the pump is able to deliver higher water flow rate through the radiator than the mechanical one, the amount of energy that can be removed by the system should be increased, as the radiator should be hotter. This may be simpler and more effective than fitting a larger radiator. You don't mention it getting hotter when when cruising at speed, so it must be delivering at least as much flow as the mechanical pump at higher revs. Thanks for the write up.

Regards.

Sean.


You’re absolutely right. My radiator has been re-cored, but is no larger, physically, than stock. At speed it seems to do very well, of course I haven’t tested high RPM over a long duration.

It is worth mentioning that after more testing, I will be replacing the stock fan with a larger modern one. The pump is doing everything it can, but when stuck in traffic the small original fan just can’t keep up.

Cheers,
- Robert

'69 Elan Plus 2
Is it still a barn find if it’s your barn?

@margosfast on instagram
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