Electric water pump

[XKRacer]

I am new here......so first hi to all.

Can anybody point me in the right direction of getting an electric water pump preferably thermostatically controlled?

It's to go on an Jaguar XK8......AJ26 engine 4.0 ltr V8. I have lost the inlet manifold and original throttle body and will replace with 8 or 4 twins throttle bodies..... but right in front where I want my air induction system to go is the thermostat tower and water pump....this I have removed but obviously need to replace.

I have an idea to make up a system to replumb all my water but need to push it..... prefer again to have no thermostat but if I have to have an inline thermostat then so be it


Any help would be appreciated

[Alex Hodgkinson]

A Davis Craig 110L/min water pump with an electronic controller should meet your requirements. The electronic controller will vary the speed of the pump to meet a water temperature you preset yourself.

They're made in Australia and readily available, I'd suggest checking ebay and staying clear of Demon Tweeks

[XKRacer]

Yeah I've looked at the Davies Craig set ups and I must admit it does tick the boxes. I have been told Renault Laguna electric pumps are often used on BBCs and are pretty good at what they do but I would have to set up a variable resistor of some sort, to regulate the speed otherwise it's back to the thermostat or maybe the Davies Craig regulator might work with it?

I have heard conflicting issues with Davies Craig and don't want to waste £200+ on something that might not work but again the You Tube video is pretty convincing

[Notso Swift]

Early EWP's had mixed success due to seal failures, some lasted some didn't, not heard of may issues in the last couple of years

If you pull out the thermostat make sure to put some form of restrictor in to keep the pressure up in the block

[XKRacer]

Originally Posted by Notso Swift

Early EWP's had mixed success due to seal failures, some lasted some didn't, not heard of may issues in the last couple of years

If you pull out the thermostat make sure to put some form of restrictor in to keep the pressure up in the block

I have read about this in some other posts and fitting a restrictor would not be a problem but how does one gauge size of said restrictor

Is it trial an error ? I guess I will need to fit a pressure gauge to be sure!

Thanks

[Notso Swift]

I think the correct way is to work out the total opening area of the standard thermostat.
You use to be able to buy these replacement Collars, but i haven't seen them for a while. (Back in the days when people though removal of the thermostat was a solution to overheating)
I know guys who have just cut the centre out of the thermostat and used that with success.

[GORDON STREETER]

Originally Posted by Notso Swift

I know guys who have just cut the centre out of the thermostat and used that with success.

That's all I've ever done and never had a problem

[XKRacer]

I have emailed Davies Craig and asked the question about restrictors/thermostats and water pressure, this is there response.....Does it make sense to you guys?

1. Pressures in the cooling system - there are three kinds of pressure in the cooling system.

System Pressure - that pressure which exists throughout the whole system due to the temperature of the coolant.
Static Pressure - the pressure due to the resistance of the system to flow and which pressure the EWP® has to overcome and is generated by the EWP Dynamic Pressure - the pressure due to the flow of the coolant also generated by the pump total pressure ( generated by the EWP®) = static pressure + dynamic pressure

The pressure the EWP® maintains throughout the cooling system is the static pressure (the resistance to flow) and then what is left over from the total pressure the EWP® is generating goes to dynamic pressure and causes flow.

2. The thermostat must be removed when fitting a Digital Controller - the Controller IS your new thermostat.

[phoenix]

Originally Posted by Notso Swift

I know guys who have just cut the centre out of the thermostat and used that with success.

Me too.

[Notso Swift]

Originally Posted by XKRacer

I have emailed Davies Craig and asked the question about restrictors/thermostats and water pressure, this is there response.....Does it make sense to you guys?

1. Pressures in the cooling system - there are three kinds of pressure in the cooling system.

System Pressure - that pressure which exists throughout the whole system due to the temperature of the coolant.
Static Pressure - the pressure due to the resistance of the system to flow and which pressure the EWP® has to overcome and is generated by the EWP Dynamic Pressure - the pressure due to the flow of the coolant also generated by the pump total pressure ( generated by the EWP®) = static pressure + dynamic pressure

The pressure the EWP® maintains throughout the cooling system is the static pressure (the resistance to flow) and then what is left over from the total pressure the EWP® is generating goes to dynamic pressure and causes flow.

2. The thermostat must be removed when fitting a Digital Controller - the Controller IS your new thermostat.

OK point 2 makes sense, no issues about that

BUT, having no blanking plate or restrictor in the system will cause lower Static pressure (resistance to flow), in the area where you need it (IE in the block). Lower pressure will lower the boiling point of the fluid. This can lead to localised boiling (especially in the head)... even though the average tempreture of the system is within normal range
THe restrictor need only be as simple as the cut out thermostat, as previously discussed but there needs to be something.

When it comes to the total heat the cooling system can take (and process) there is a balance between pressure and flow (and the heat rejection capabilities of the radiators). These guys are taking the high flow low pressure route, but the manufacturers have designed the engine with a degree of pressue in the block.

Actually, now I think of it, I know a guy in Aus who works for Ford on exactly this topic as a Cooling System Engineer, I should have a word too him.

Speaking of lowering the boiling point, this is not always that much of an issue, there are products like Watter Wetter that have a lowered boil point, but also have a higher heat transfer
There are other non water/Glycol baded products like that Evans NRG, not sure what that is made of, but it requires no system pressure... BUT it still has static pressure in the block.

[XKRacer]

OK so putting in a restrictor to aid block pressure to raise the boiling point seems to be the tried and tested way to go.....I just need to find a place to put it.
Where the thermostat use to be no longer exsists. I have replaced the water pump with a housing that is just basically a pipe connector from the bottom of the rad, inside this I could turn up a disc with a hole (start smallish and drill out until it works?).

See what happens.......This is all a bit new as far as i know nobody has done this before on this engine, Apec have done a crossover throttle body setup where as I am going for a more traditional straight up affair and I am not sure what they did about the cooling side of things.

I am having a larger core radiator made at the moment to help things along and expecting my Davies Craig EWP to arrive today.....Proof is in the pudding as they say.....hmmmm why they say that I have no idea

[GORDON STREETER]

You could use the type of thermostat that fits inside the top hose (Renault 5s etc) with the centre removed. This will at least give you an idea and would be easy to make and fit something like it, and easy to remove when experimenting.

[phoenix]

Or you could reduce the diameter of the outlet pipe from the head by using a to a piece of ally tube, with the same ID as the hole in the original thermostat, between the head and the pipework that runs to the radiator.

[XKRacer]

Originally Posted by phoenix

Or you could reduce the diameter of the outlet pipe from the head by using a to a piece of ally tube, with the same ID as the hole in the original thermostat, between the head and the pipework that runs to the radiator.

That is what I was thinking(ish)....the outlet from both heads will be joined by an ally tube of which other outputs/inputs go into, heater pipe and temperature switch for the fans.
What I thought is....I could machine a piece of flat aluminium the same shape as the flanges of the outlet pipe into which I will drill a couple of holes comparable to the flow of the once thermostat as a start point. I can then easily remove and drill bigger as required.

What do you think?......would that work?

I will post some pics up once I've done it.

[phoenix]

Originally Posted by XKRacer

I could machine a piece of flat aluminium the same shape as the flanges of the outlet pipe into which I will drill a couple of holes comparable to the flow of the once thermostat as a start point. I can then easily remove and drill bigger as required.

What do you think?......would that work?

That sounds ideal to me...

[Notso Swift]

And to me.
I think you are on the right track with the whole project, remember, you still need to keep the volume up to a reasonable level, so don't go too small to start.

I think I read some where (may have been here LOL) that F1 use something like 60 psi static pressure, as in at the radiator cap, pretty much usless information, but I thought I would throw it in!

[XKRacer]

All info is useful.

This is my first attempt at building a track car so I will have many other questions

A lot of the other threads have been useful especially when it comes to suspension/geometry as I will be changing all of these to coil overs.

I have removed as much metal as possible. The bonnet I have redesigned and will take a mold and produce in carbon fibre as well as the front wings.

The interior is gone, I have fitted a T56 from a Le man/race prepared Viper (Jaguar only produced XK8/Rs as autos) I will change the diff to a quaife helical LSD also got to get a new crown wheel and pinion made that was to be a question I was going to ask later on.

Glass has gone replaced with plastic.

Doing some big mods to the engine and will probably blow it up but thats part of the fun


This forum is brilliant you guys have been very helpful

[XKRacer]

Thought I would add these pics to this thread I still need to sort the plumbing I am changing it again







Thanks for all your help