Water pump impeller - Which one should I use?

Well since it was mentioned, who has implemented a two electric pump replacement for the OEM, and can any insight on their solution be provided. :zipper_mouth_face:

beachcar 5 , look up Craig davis(davis craig) Australia !

and R&D never stops , a NEW design impeller has just been made ,it is totally different from what we have had for 75yrs or more! i 'm always ahead of the curve ,curse of my life!
ron

Nev.W (Neville) has installed twin pumps. He said he initially installed a single Davies Craig 80LPM pump, but that was marginal. He then installed twin pumps. I believe he consider there to be significant benefit in allowing different flow strategies (for example, after run) based upon what the car was doing. Not sure if he ran them in series or one for each bank.

I can’t personally comment on the Davies Craig pumps. I did buy one, but was surprised (and disappointed) by how small and flimsy it looked. But they now have alloy versions. I haven’t had a lot of luck with plastic radiator header tanks etc in modern cars. They can’t seem to take the heat cycles without cracking. The advantage of plastic might be the lack of corrosion …

I assume by now there are brushless pumps on the market.

There are a number of US manufacturers (Moroso?) that have “billet” pumps to suit various American V8’s. They might be adapted to fit the front water pump plate on the V12.

GMB Japan (https://www.gmb.jp/en/product/cooling/e_water_pump.html) make electric water pumps for EOM. The trick would be to find an EV or HEV that uses one and buy an OEM one.

Meziere have a remote pump that does 75LPM (20GPM) @ 5A ali and includes a bleed port. Reportedly only produces about 5psi of pressure. Not sure if that is an issue or not.

Be a nice project for someone to develop the definitive cooling solution !

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Have a new but not OEM water pump which I hope to have time to start installing soon. This “New” aftermarket pump was supplied by a west coast supplier which has proven to be reliable in the past. How ever this pump has a couple of issues. They are the impeller is set back from the face by over 0.055 on an inch and some of the vane tips are “raged”. Measuring the impeller hub end to shaft end there is room for the impeller to be pressed on further. Not sure how much clearance the vanes should be set to the pump body.

The V12 water pump flows 355 litres/min at 6000rpm but we are missing the static pressure at that flow to specify a pump. I suspect that the latest DC pumps will be brushless DC versions to get rid of the commutators but would they be more reliable than a belt drive to a mechanical pump. Possibly…are electric pumps the latest solution for moving coolant???

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For the Jaguar V12, the definitive cooling solution is coolant filters and a single-pass aluminum radiator. Changing the pump scheme is fun but doesn’t address the issues here which involve the radiator getting plugged up.

If I were going through the trouble of going to a single pass radiator I would have a radiator made with vertical cooling tubes with top and bottom tanks. IMHO a down flow radiator is the solution jaguar should have implemented instead of the dual pass setup. Getting a down flow radiator surface area to match the cross flow might be a challenge, but the result would gave been a better cooling system.

The SIII E-type had a downflow radiator. The question is, why did they opt to mess up that perfectly good arrangement when they put the same engine into the XJ-S?

Maybe no one imagined it would get clogged up.
Maybe no one was expecting them still to be running 44 years later.

Perhaps with a positive spin you could argue that it is amazing that these things are still running, and running so well !

Or to look at it another way, the only thing out there that includes “self healing” as part of its specification is the human (animal) machine. Now, if you could just put something in your coolant, that could detect “junk” and send Killer T-cells to gobble it up whenever it appeared, you would be on to something. Must be a chemist out there that could find a solution (:face_with_hand_over_mouth:). Then again, I guess a filter is pretty simple.

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The clearance is specified as 0.025 in. both the Jaguar Repair Operation Manual and the Hayes Automotive Repair manual. Visited a customer shop to and they let me use their arbor press to set the clearance.
The weather here is going to be rain, rain and more rain so no golf for a while and will get after the needed repairs.

The new one will provide more flow at lower rpm. with less chance of cavitation at the higher rpm. the V12 is capable of.

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Cavitation can be an issue at high rpm. because the flow is controlled by the thermostat. the “pump” is not a pump in the true sense, it is merely an agitator, just like the agitator in your washing machine.

Before you press the impeller onto the shaft further, make sure there is a gap between the base of the impeller and the seal. On most of these, I end up machining the impeller so it can be pushed on further without crushing the seal. That way, the correct clearance is obtained.

How much seal spring should be compressed when installing it into place?

As the seal is already assembled and under spring pressure, very little additional is acceptable. To much and it will wear out the sealing surface quicker.

That makes sense, but how much is “very little”? :slight_smile: It should be compressed a bit so 2 metal parts that hold the seal together don’t rub but is that 2mm or 0,5mm? What would you suggest?

What does the manufacturer of your seal recommend? It should be installed to that spec whatever it is. Pushing on an impeller that moves it more will change that spec. Not recommended.

Good question… I just bought a rebuild kit and there where no instructions. Have tried searching the web but no luck.

I use special collars that push on the main housing and the center of the seal at the same time. Not sure how else you could properly install them. Also, note on the V12 that there should be 2 seals in the kit as there are differences in the housings. Have you considered having your original pump rebuilt?

Yes I have a spare leaking pump which I’m going to try to rebuild.

I already figured that out and it’s not a problem for me to make one if I would only new how much further spring should be compressed.

It was only one seal in the kit. what are the differences between the two? OD?