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MG Midget and Sprite Technical - Electric cooling pumps

Hello.

Has anyone had any dealings with those electric coolant pumps now found on Mercedes and other such cars. I was wondering if they could be used instead of the mechanical pumps so that a different radiator system could be fitted. Not the Davis-Craig ones.
It would be handy to know if they can be run full time and what lifespan they have.

Thanks

Rob
r thomas

You might find some details and info here

http://www.carbuildersolutions.com/uk/electric-water-pump-115-lmin
mark 1500 nearly on the road

I looked into those several years back....the consensus here on the BBS was that for track days they would be great, for a lot of highway driving, they would be okay, everything else kind of driving and it was just broad swords vs battle axe pandemonium

Its so new a idea, everyone has an opinion.

In the end, we all settled for keep an extra spare pump in the boot for just incase

Truth be told... id device a clutch on the crankshaft pully similar to an auto AC compressor that can be turned on and off as needed...maybe hooked up to a senor of some type

Prop
Prop and the Blackhole Midget

What about the viscous coupling used on engine fans, they're supposed to slip at higher revs which would give an approximation of the desired effect (perhaps)
Rod
R W Bowers

I asked a similar question a while back and got the 'OK for racing but not for the road' reply.
But I don't think anyone has actual experience of electric pumps on a road car.
There were questions regarding the reliability of the pump against the mechanically driven pump.
I would ask how often a modern fuel pump or central heating pump breaks down - not old SU pumps! Mine just sits in an inhospitable environment and pumps fuel (or heating water). Never let me down.

With a good controller and a suitable capacity pump, well set up, I would expect there to be several advantages.
Better economy due to faster warm up and less drag on the crankshaft, because you are only pumping water round at a speed that is adequate for the cooling needs of the engine at a given time.
Better cooling due to the pump not being reliant on engine revs. E.g. crawling uphill on a hot day. My engine does not like these conditions as the engine revs cannot pump coolant round quickly enough.
Less power absorbed from the fan belt as one one devise is being driven. Yes, there will be a bigger demand put on the alternator due to the fact the electric pump needs to be powered but it should take less energy than the mechanical pump which spins too fast at high revs.
The ability to have the pump continue after shut down may save a head gasket or two.
The only disadvantage may be reliability. If the pump did stop working it is likely to do so without warning and you are stuffed. If the mechanical pump breaks it is likely to let you know sometime before with some sort of noise so you have a chance to replace it before it finally goes. If the fan belt goes it can be bodged with a pair of tights. I always carry tights or stockings with me for this eventuality (I could carry a spare fan belt but have never needed to as I replace the fan belt when it looks tired) ;). If the fan belt goes, normally, you should have replaced it some time earlier so you should only blame yourself.

Just my thoughts, no evidence or proof yet, please don't crucify me.

Dave
Dave Brown

Thank guys.

The engine in question is an Austin 7, circa 1933 and it has no pump, relying on thermosyphon. Since there have been a few racers putting electric pumps on Midgets I thought there might be some 'experience' on here.

Thermosyphon requires a water capacity of at least a gallon to operate and the radiator core needs a large flow rate, not something modern cores are known for, hence the idea to use a modern core and to add a pump. I'd like to try one of these <1 amp pumps that pushes 10 litres per minute but I don't know if they run full time on modern cars or just after switching off.

The extra amps to run it will be nothing compared to the power required to run a mechanical pump.
r thomas

Hi,

I remember Brian Cox used a salvaged electric water pump (from a modern car) for one of his thermosiphon cooled '30s era cars, in Practical Classics Magazine, somewhere around 2000.

Seemed like it couldn't hurt, when used on an old car that already has thermosiphon but needs a little bit of help.


Never seemed like it would be worth the effort for converting a modern road going car.

Probably worth doing for all-out racing though, for that extra 1/4hp under certain conditions + ability to reduce the size of the cooling system a smidgen further (less weight on board).


Norm

Norm Kerr

Hey R

In your situation of a 30s era engine with no water pump built in, id say go for it, nothing to lose and only gain to be had

If it was a 1275 engine id be indifferant

Good luck

Prop
Prop and the Blackhole Midget

I have used the Davies Craig type on my frog (race) to good effect. Once set up and free from air locks I think they are great. The ability to circulate hot water after engine is shut down is a big advantage imo.
I also used a Bosch cylindrical type on my old C class car for a while. Same as sold here http://www.corley-conversions.co.uk/ but mine came from a scrappy for about £5; from a vauxhall calibra i think. Much less obtrusive than the Davies Craig type. I did struggle with that one though - may have been my plumbing skills rather than its ability. I still have it in the garage if you want it Rob - im never going to use it.
John Collinson

Thanks, John. Very kind offer. I'll get back to you if I can't find a shorter one locally. Not much space under the A7 bonnet!

That is the sort of thing I was looking at down at the scrapyard at Llandow. If you think they can survive a long-ish run rather than just the post-shutdown headgasket protection cycle then it ought to do. I wasn't sure if they were only designed to run for a few minutes of engine block cooling or if they could run for maybe an hour.




PS Was it you that collected an engine block from me a few years ago in Llantwit Major?
r thomas

To add to John's comment. I have had trouble with the Corley unit on a racer. The rotor seized and stopped pumping. Overheating or what. To be fair to Corley it was not really the fault of the unit itself. However the fact that it uses a magnetic drive exacerbated the issue. I was using a block from (a no longer used and never mentioned here) engine builder who had not properly cleaned out the water passages after machining. They were full of fine swarf which was picked up by the water flow and proceeded then to be caught by the magnets in the pump jamming the drive. I'm sure with a properly cleaned block it would be fine but worth a check now and again as it would probably also catch rust flakes.

I have also used an old BMW 7 series heater pump as an auxiliary to stop heat soak when the engine is stopped after a race.




Mark Lister

Thanks, Mark.

What is the difference between the Corley type unit and the BMW one? With 13bhp on tap I should be able to get away with a small pump if it is able to run constantly.
r thomas

Yes, that was me - well remembered. These things aren't very big and many are used on the mini miglia racers rather than the Davies Craig units aparantly. If you drop me your address I'm happy to post it to you.
John Collinson

Thanks John.
I'm at 37 Heol Merioneth, Llantwit Major, Vale of Glamorgan, CF61 2GS.

Perhaps I can return the favour somehow or offer a cuppa and a bacon sarnie next time you visit Llandow? About 1/2 mile from me.
r thomas

Rob

I'll try and dig them out of storage and put up a couple of photos.
Mark Lister

Herewith photos.

1 - the Corley pump complete

Mark Lister

2 the magnetic drive of the Corley pump. The screwdriver is holding the rotor out to show the small clearance between the rotor and the ? Stator where the swarf collected.

Mark Lister

3 - the BMW heater pump. There are several similar on Ebay at the moment. Not sure what this one is from - possibly 80's or early 90s 7 series.

Mark Lister

In the post Rob. Looks very similar to the BMW one - probably a generic Bosch type.
John Collinson

I've got a Bosch catalogue which details many of their automotive motors and actuators suitable for other applications and it includes water circulation pumps. When I've looked the same details as in the printed catalogue can be found online with technical details and part numbers so may be worth looking to see what details Bosch give.
David Billington

R
I've got a tuned A7 running original header with modern core (standard width). Never boiled ever whilst trialing , hillclimbs etc in the UK and its never boiled here down under for fast road use in 30 to 40 deg ambient heat. Does get a bit hot on the highway at constant high revs buy never boils even though its only thermo syphon. I would suggest get a 'export period' 4 blade fan
(see any of the A7 specialist or John Barlow) and use a decent sized header and if you are worried a thicker modern core. Getting one made would be cheaper than an electric pump and save the already limited charging system of a C35 Lucas dynamo.
Ed
Ed H

Thanks John! It was waiting for me when I got home from Gatwick.

Ed. Sounds good. This rad doesn't have the original header tank so the water volume/capacity is much less than normal. I might need to add a small tank to increase the total volume of water in the system but it will have to wait until it is all finished and on the road. If you've got any photos.... :o)
Also, have you gone to 12 volts? The pump draws less than one amp at 12 volts, according to the Bosch details
r thomas

R

Yes running 12Volt but if you draw too much power the Austin dynamos tend to get a bit hot, and as they are connecting directly to a bl**dy hot engine they have a tendency to overheat.

Picture of rad attached (only running 2 blade fan) will post a pic of a 4 blade fan separate.
Ed


Ed H

Pic of 4 Blade fan , they used these for all export models to hotter climates. Bear in mind that Mag engines and coil engines fans are different rotation and shapes.
Ed


Ed H

This thread was discussed between 18/01/2014 and 02/02/2014

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