Davies Craig Water pump

Elan Diskussionen
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1

Hi all

Over the years, my Sprint has been used as a bit of a test bed for all sorts of wacky ideas - some good and others not.

I used to run an electric water pump (Davies Craig) which was very reliable, but the installation required the removal of the thermostat and the use of the outer thermostat ring only. This meant that it took a while for the engine to warm up which was OK in the summer but not great in winter. In this set up, I ran my Twin cam with the original water pump retained but not driven by a belt.

I ran a 2l Zetec for a while which was unbelievably quick but with the prospect of my son wanting to drive the car, have recently refitted the original twin cam. The rad that I used throughout (and continue to use) is mounted in the front and despite the fact that I am now using the original water pump. I decided to keep the Davies Craig pump in the system and I use it with the fan on hot summer days to reduce heat soak once the engine is turned off. I do have a normal thermostat and I make sure that the DC pump is off by 85 degrees just in case

I was wondering what might happen if on a hot day (remember those) with the engine idling in traffic I used the DC pump alongside the mechanical pump. Would it create cavitation and cause havoc or might it help keep the temperatures down? Easy to check prior but I recall they they both flow in the same direction.

As usual, thoughts gratefully received.

Thanks

Gavin

2

Hi, I have a Davis Craig water pump. Somewhere, on their website or hard copy instructions it said you could use a thermostat if you drilled a hole(s) in it. I think it was a single 1/4 inch hole, but at 79 my memory is BAD. I did it and had no problems. It was still slow to warm up.

Bob

3

Thanks for the info Bob

Do you still run a standard water pump or have you disconnected it from the system (or omitted it completely)?

Gavin

4

No mechanical pump, just a blanking plate made by my engine builder.

5

If anyone is interested, here is a video showing my Davis Craig installation.

I installed it because the stock pump developed a small leak. Like you, it is slow to heat up. According to the directions, you can adjust the temperature before the pump comes on, but I haven’t had much luck getting it to work. I’m sure I’m doing something wrong. The good news is I noticed a significant power increase.

6

So much for “simplify and add lightness”. Didn’t you still need to remove and replace the stock water pump to address the leak?

7

No I didn’t. I did this several years ago, so far it is not leaking.

8

On reading your original post, one is left with the impression that there was a small leak?

9

The other reason was if I grabbed the fan blade, I could move it back and forth. The bearing was failing.

10

Are people with the DC pumps running the DC controller with it, or just “turning it on” when the engine starts? I think their controller does very short pulses during warm up, then gradually transitions and ramps up to full flow as the temp increases, so you get a quicker warm up.

11

I did both - I kept the water pump and isolated it by using a shorter belt and used the controller. I found that because I had removed all of the thermostat but for the ring, it was over cooling so they told me to fit a diode to rein back the settings which worked but it was still slow to warm up without the thermostat.

I now run the TC water pump and use the pump manually to supplement. My question was to see whether it might be ok to run both in parallel while sitting in traffic…