MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG Midget and Sprite Technical - electric water pump

Has anyone fitted an electric water pump to their midget/Sprite? I quite like the idea but they seem expensive and quite difficult to fit. Has anyone any experience of them?
Have a good weekend.
Thanks
Dave (Looking to spend/waste more money!)
Dave Brown

I have thought about it but have decided against it

-expensive
-risk of failure
-lack of benifit

So I'd be interested to hear why you think it is an interesting upgrade?
Onno Könemann

What is it about the mechanical water pump that you don't like? Surely this comes into the category of 'if it ain't broke, don't fix it...'


On a race car where you are searching for the final few bhp then yes - otherwise why?
James Bilsland

I should add that I have seen a couple on race cars that don't work properly because they have not been plumbed in correctly - If you're not careful it appears to be quite easy to arrive at the stage where the pump is trying to pump water both ways through the engine...
James Bilsland

Hi Onno,
To me, it seems a much better way of controling engine temperature, allowing maximum cooling capacity whenever it is needed and not pumping lots of water around when it is not needed.
I would imagine it would cause the engine to warm up quicker and would be less drag on the crankshaft as the mechanical water pump is not being driven. OK, the electric one needs electricity which must be generated by the alternator via the fan belt so it is not free energy that drives the electric pump.
My mechanical system, like everyone elses, uses a thermostat to control the flow of water through the radiator, an electric fan that is thermostatically controlled to come on when it is needed and a pump that is controlled by engine speed.
Some air is forced across the radiator which is determined by the speed of the car and the external environment - head wind, tail wind, slip stream of the vehicle in front etc.
Cooling requirements are determined mainly by the load on the engine and in some circumstances I think my existing system struggles to provide adequate cooling. It got very hot crawling up the Hon Fleur bridge in Normandy in the summer in nose to tail traffic.
Yes, Nigel, before you comment, the radiator has been flushed and I am running neat 4life coolant and the engine has been fully serviced and rolling road tuned ;)
It has been mildly tuned and produced 90bhp on Peter Baldwin's rolling road which is quite generous (I think nearer 80 on most others), so I think the original system is about on the limit.
The alternative is to get a higher 'capacity' radiator. Moss are selling an alloy one for £364 which they claim gives 40% more cooling, whatever that means.

Dave
Dave Brown

Hi Dave
What you are talking about is an properly complicated system with a lot of chances for failure.

And the problems you describe are just minor troubles to be expected in the conditions and solvable with small adjustments.

For a hot midget engine I would take an other approach:
-close the bypass
-88 degree thermostat with 2 6mm holes in the rim
-remove the mechanical fan
-fit electric fan thermostaticly controled with overide

this will give you
-faster heating up
-less power drawn because fan is eliminated most of the time
-better heat controle at low speeds due to electric fan.

Onno Könemann

Onno, I think Dave's put that he doesn't have a engine driven fan unless I'm wrong (again) and I've never understood the need for an overide switch on the thermoswitch it's like having a dog and barking yourself :)

Dave,
I'm sure you meant, and have done, it's not just the rad that needs cleaning and flushing but also the engine (and heater matrix) too :)

I've been with Peter Baldwin for RR tuning (I didn't bother with a power read out) and I've been on Peter Burgess's RR tune-up and others

go to Peter Burgess for a RR tune-ups
Nigel At

Nigel
You are right i did miss that.
And why? i do not trust thermostatic switches 100% ;)

If the engine is fine under load at speed than the only thing needed at low speed is better air flow.
So a better fan or ducting is needed
Onno Könemann

Hi Nigel,
I am planning a trip to Peter Burgess's RR in a month or so and I did clean the block and heater matrix too when cleaning the rad.
I have, however, had the heater water valve closed all summer and I have read today in a Mini Spares article that it is not recommended to run with this closed. You should re route the water from the heater take off to the radiator so that No 4 combustion chamber gets some cooling if you are going to shut off the heater. Why this was not done in the factory if it is such an issue beats me.

Onno,
I have removed the mechanical fan and I am already running an 82 degree thermostat for the summer. I will be changing back to 88 in a few weeks. I still have the bypass hose fitted. I have been trying to find out what effect blocking the bypass and drilling a few holes has on the cooling. Does anyone know?
Yes, there are chances of failure with an electric pump and controller, but are they much greater than a mechanical belt driven pump?
I was really just trying to get feed back from someone who has first hand experience for future reference.
Thanks for your comments.
Dave
Dave Brown

Onno,
A better fan may be good, also vents to let the hot air out would be a benefit too.
Something that I have only just remembered, on my trip to Normandy in the summer, whilst cruising along the auto routes at about the speed limit, the temperature would be about 90 for an hour or so. Then we would stop and the next stage the temperature would be nearer 100. Later on the temperature would be back to 90 or 95ish. This happened regularly. I didn't want to worry about it too much as the car kept going and it didn't overheat or lose any water. I just couldn't quite work out what was happening and why it would not run at a constant temperature.
Dave
Dave Brown

Dave
I am amazed it worked that well with the heater blocked off!
Just open the heater and close the fresh air flap and your problems are history.
With the fresh air flap closed the additional heat in the footwell should not be that high.

Blocking the bypass sends all coolant through the radiator all the time.
The holes in the rim of the stat are there to ensure flow when it is still closed.

As for the chances of failure.
In my experiance electrical failures are more comon than mechenical ones.
And the electrical pump can fail without you noticing.
Only the temp gauge or engine failure will tell you
If the v belt fails the alternator/dynamo fails as well and produces a red warning light.
That will make you stop and check preventing engine damage
Onno Könemann

Dave, I've seen a lot of electric water pumps used here in the US but primarily on drag race cars where the engine is only running for a few minutes at a time. Saves on parisitic horsepower drag so worth it for the racers. Finding an electric pump on a road race car is almost impossible. There the benefits of having constant circulation of coolant and the reliabliity far outweighs the horsepower gain.
If you install an electric pump and connect it through a thermostatic switch where do you monitor the coolant temp? Without circulation it's entirely possible to get hot spots within the head that wouldn't show up at the thermostat sensor until you'd already boiled the coolant. Wire the pump to run all the time and then you're just moving the parasitic loss from the mechanical pump to the alternator, no real gain. For the most reliable cooling and least horsepower drag spend your money on custom made geared pulleys for the engine, takes the tension off the water pump bearing and you eliminate belt slippage as well.
B Young

Dave,
I've seen this about having the having the heater valve closed and also converse opinions

IIRC you've got a 1275 and it sounds like it's about the same power as mine - you'll know for certain when you visit Peter Burgess - my car runs cool with normal stat and electic (thermoswith only) fan

my heater matrix gets very hot so I have the (Ashley Hinton) heater valve full closed most the majority of the year but everything still plumbed in case there's "a chilly day" and my wife is in the car

what water temp do you have when on the open road and how high does it rise when to static in traffic

Onno,
no you have a switch on modern vehicles yet you trust them (?) :)
Nigel At

Nigel
I don't have a modern and do not trust them at all ;)
Our newest car is from 1974
Onno Könemann

Onno, yeah sorry I thought that was the case but couldn't remember for sure and had to rush out to a local beer fest so couldn't check

do you have an overide on your central heating at home, yes of course you do and you use it often, why not forget it and use manual controls all together

each to their own and whatever gets you thorough the night

logic has little to do with living - I get worried when I see hieghts from the safety of my TV screen
Nigel At

We have an EWP on the racer and it works extremely well - James will attest that my bespoke cooling set up is NOT plumbed in incorrectly, and that it addresses the problems with No 4 Cyl overheating in highly tuned motors :) I would say (of course) that it is a far more elegant solution than those used on most racing Midgets and allows us to run a 'letter box' rad intake while holding the engine water at the perfect temp for an A Series lump.

Having said that, I doubt it is of any worth on a road Midget running std sorts of rpms with no cavitation.
Deborah Evans

An advantage I didn't notice above would be having the ability to circulate water after the engine is off which should be more effective than running an electric fan with water not circulating.

Peter C
Peter Caldwell

I had one on the race car. Took a bit of sorting to get the circulation/plumbing right but when it was sorted was great.
Yes, there is the risk of failure but I have seen more fan belts snap than I have EWP's fail. Main reason for me was the ability to circulate water after the engine was off. Also, have sat on the grid watching others nearly boil while mine never got hot at idle, even though there is no electric fan.
John Collinson

When this was asked on another forum I am on, someone complained that theirs died after just 9 months of road use, and left them stranded for 2 days while they got a replacement - probably more likely an issue here in Aus than in the UK, but still. This was a Davies Craig brand unit, which is the normal one over here. They didn't honour the warranty on it either.
AndrewF

This thread was discussed between 02/09/2011 and 08/09/2011

MG Midget and Sprite Technical index

This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.