Water pump options

[Jacko1234]

Whilst the engine is out of the car and the inlet manifold has been removed I was thinking of going for either an electric water pump or a belt driven external water pump conversion both seem quite costly just wonder what people’s thoughts are on this. The other option is rebuilding the standard impeller and possibly using Evan’s waterless coolant, is there any advantage as there is no pressure in the cooling system? I would like to hear from anyone using any of these and possibly a picture of the EWP setup in the engine bay. Many thanks.

[trunt]

You can check my EWP installation at https://terryhunt.uk/stag/cooling.html and my article for the US Stag club Here: https://terryhunt.uk/stag/ewp.pdf

If you go EWP then Evans is out as it is not recommended by Davis Craig due to its high Viscosity (TBH I'm not a fan of the stuff ) I like some of the advantages of the EWP and as I didn't even have a stock pump at all the cost was somewhat negated. I elected the front left position, but more common is the front right, in place of the alternator which needs to be moved.

There are quite a few threads on all three in the forum on the subject and Many correctly say that the standard setup in good condition works fine.

[richardthestag]

google waterless coolant, plenty of information available about the downsides

[jbuckl]

I bought the ewp kit from wards.

(Not the latest all singing - literally! All dancing controller though)

Didnt end up fitting it in the end.

Only items missing is the brass bung. &1 m5 cap screw.

Been in the shed ever since.

Available £460.

Reason I didn’t fit it was because of a dislike of extra wiring.

Also read about possible added heater issues.

The latest controller is a bit intrusive…. Constantly telling you what it’s up to with beeps flashing screen etc.

[trunt]

Heater issues are solved by plumbing it in properly. I have the latest model and don’t get constant beeps- only if something is wrong it’s very rare. The only one that I have had is if you start on a really cold day and just idle the water temperature doesn’t rise quickly enough so it’s programmed to warn you in case e.g. the pump wasn’t working.. (but that may have been before I reinstalled the thermostat?) However as my controller is hidden away in the glove box I couldn’t see or hear them anyway! What I do have is a fair sized warning light on the dash that would alert me should anything go wrong.

I will admit that for the first few trips I was watching it like a hawk but once I was satisfied all was well the glovebox lid was closed and I rely on the stock temperature gauge.

There are 3 versions, 1st just had led indicators, (the one Julian has?) second a white looking led display. Third has a dark display, Alll will work fine.. each version has more functions e.g I can turn the fan and pump on full, or just the fan and it monitors more things. Though TBH I preferred the second versions screen, newest one is pretty hard to see, not that I look now

[FrenchStag]

I used Evans classic coolant, more out of ignorance than anything else. The big disadvantage is draining and refilling the system will cost you unless you manage to re-use it all. And if you spring a leak you get green gunk everywhere.

That being said I haven’t had any issues 2 years down the line.

[MikeParker]

I am probably on my own here, but I like the the original pump solution. It runs continuously meaning water is circulated around the block all the time, distributing heat and preventing the hot spots than can give head warping problems. The flow increases as the engine power and revs increase. I have the original pump at 165K miles and, apart from the seal going on one occasion, it has given no trouble. The trick is to get a pump spindle (gear) that is sufficiently hard and a seal that does not present too much drag. The final part of the jigsaw is to make the clearance between the impeller blades and the pump cover is correct. Too big a clearance and there is not enough flow around the block. Also make sure the thermostat has a "foot" plate to shut off the by-pass route when the engine is hot. If all that is OK you will have a trouble free, efficient cooling solution.

[wilf]

I also use the OE pump (although replaced by one configured as Mike says above). Funny how the exact same pump in the Dolly Sprint I had years ago never had a reputation for being troublesome, nor was it in my ownership, and I ragged that car hard - XR3i beater it was. (although the fan viscous coupling did let go, some things never change)

[mike@thenook]

I have Steve Hills external belt driven pump which is essentially a modified Ford item - I like the simplicity of it and seeing that it is working, rather than being buried under the inlet manifold which is in itself an absolute pain to remove and reseat without unsettling the heads too.
My main concern with the original pump is that it is running at the top of the engine whereas the external unit pumps from the lowest point so it will never be without water, unless of course you have lost it all which is unlikely, even in a Stag!

Cheers

[flying farmer]

I have one of the belt drive conversions on my MK2 and an EWP on my Mk1. They both retain the thermostat and a working heater

My first original pump failure was on a Dolomite Sprint, it was chattering at idle, the drive teeth were nearly stripped. This was my first EWP conversion

I had 3 original water pump failures on 3 different Stag engines in the space of about 4 months 12 years ago. One was a slow leak from the seal, another dumped the contents of the cooling system within seconds when the rubber bellows between the cage and the seal split. Fortunately I had just reversed out of the garage and got out to shut the garage door when I saw water pouring from below the engine. The other failure was a seizure which snapped the timing chain and wrecked the engine. At this point I decided I only wanted external pumps.

Both belt drive and electric do the job perfectly well, though I only use the electric pump and not the controller.

I did this because my first complete EWP installation was on my Rover V8 engined Toledo and heater output was worse than pathetic, the inside of the windscreen would freeze while driving in minus 5 temperatures.
I had previously fitted a pump only installation to my Dolomite Sprint and my Stag engined TR250 and they worked brilliantly, so I refitted the thermostat to my Toledo and binned the controller, it is now useable in the Winter.

It was a no brainer to go pump only on my Mk1 stag. I use a Mk1 Stag ceramic ballast resistor on the pump feed to all my EWP installations, it drops the running voltage to about 8V which is perfectly adequate in nearly all conditions. I also fit a ballast bypass switch to give the pump full voltage for extreme use such as track days and towing my trailer tent around the French alps in 40 degree heat.

I did once have a ballast resistor fail due to mounting it too low down, water splashes corroded the connections, so the bypass was usefull on that occasion. I relocated the resistor higher after that.

The pump only solution is quite cheap, apart from the pump it just needs a variety of bits of tube and silicone bends but obviously you need the skills to join it all up. I located my pump low on the LH side of the engine so I didn't need to relocate the alternator, saving even more money. On the engine in my TR it is mounted higher on the LH side, just below the head, as it is the only space available

Neil electric pump 1.jpg

[jakesmig]

I installed an EWP system to my RV8 lump and am pleased with how it works. It has the controller, a thermostat is still used though it has a 2mm hole drilled in the valve, and I use a seperate small electric pump to feed the heater circuit. Warmup is quick and the heater is very hot.