Electric water pumps.

Post Tue Jun 14, 2005 4:21 pm

Just wondered if anyone had ever though/had done an electric pump upgrade. Loads of people have done electric fan conversion, but nobody had done a water pump from what i can see.

To me the advantages would be,
Less drag on the engine, possible realising more power...
You could make it so that it runs for a little while after switching off in order to reduce theamount of pressure building up in heads...leading them to crack.

Problems
Less drag from mechanical pump, but maybe more from the alternator?
Have to do something with current water pump. i.e take out its internals....
Cost a bit more, demon tweeks sell them for around Ãƒ”šÃ‚£90

What do people think?

Post Tue Jun 14, 2005 4:35 pm

is that possible????????????????

Post Tue Jun 14, 2005 4:41 pm

anything is possible!

Post Tue Jun 14, 2005 5:22 pm

Thought the same thing in the past but never bothered to investigate.
Have you got a link to demon tweaks ?

Post Tue Jun 14, 2005 5:22 pm

Im just about to start a V6 conversion on an Astra GSi using a Calibra V6 motor.
I havent looked at it much yet, but the V6 seems to have an electric water pump as well as a mechanical one. I think its meant to run on with the fans after you switch off, to stop the heads from cooking themselves by circulating cooler water from the rad.

Im not sure if its an auxiliary thing or how/where its plumbed in, but will have a look when we get the V6 out.

Post Tue Jun 14, 2005 5:25 pm

nice 1 jmc

maybe thats the way to stop the e30 heads boiling away???

keep posting will be interested in adding a elec pump if its gonna work?? Daz

Post Tue Jun 14, 2005 5:31 pm

Found it.
So you would have to fit an electric fan as well.
How long would 15000 hours be for a standard car ?

Post Tue Jun 14, 2005 5:32 pm

Hold on i've got a spare one of these off the washing machine

Post Tue Jun 14, 2005 5:36 pm

ffs dnt tell me i need a fan and pump from a washer :lol:

scrapped 2 of the buggers last week :lol:

Post Tue Jun 14, 2005 5:38 pm

dazleeds wrote: maybe thats the way to stop the e30 heads boiling away???

Thats what I thought.
Not sure when the V6 will be coming out yet, might not be untill the end of next week but will post what I find.

They way I see it is, the electric fan cools the water in the rad and the electric pump makes sure that cooler water gets to the head and other important places. Would probably need a thermo switch of some kind to turn it all off when the temp has dropped enough.

Post Tue Jun 14, 2005 5:41 pm

jmc
does that mean it will run the pump on a realy hot day and kill the battery

Post Tue Jun 14, 2005 6:05 pm

If the oustide temp is hot enough to raise the water temp then yeah, I guess so.

Im not sure how it works on the Calibra so I am only guessing, but I reckon its worth looking into. Id rather have a flat battery than a cooked head.

Post Tue Jun 14, 2005 6:22 pm

Here you go Ãƒ”šÃ‚£90 or near offer (courtesy of hoover) :lol:

Post Tue Jun 14, 2005 7:06 pm

There are actually 12v ones from caravans on ebay, dunno how good they would be...!

As opposed to a thermontime switch i would have a timer of some sort on it, so it would stay on for 2-3mins when you switched off, that way your less likely to fry the battery.

link to demon-tweeks
http://www.demon-tweeks.co.uk/catalogue ... rom=search

Post Tue Jun 14, 2005 7:08 pm

15000 hours be for a standard car

Thats about 2 years with it running ALL the time, i would say at least 5-10 years....

Post Tue Jun 14, 2005 8:30 pm

It should out live my old banger then.
Or make a good selling point. (optomistic

)

Post Tue Jun 14, 2005 10:59 pm

My recently aquired M54 engine has an electric water pump in one of the hoses. Haven't checked it out yet, but I suspect it just used to continue circulation after the engine has stopped.
No advantage in replacing the main water punp with an electric one, as it would have to run continuously, and would absorb more power, via the altenator, than the standard water pump.

Post Tue Jun 14, 2005 11:21 pm

Brian
The pump in the hose you have, is it BMW ?
If so have you got a part number please ?

Post Tue Jun 14, 2005 11:59 pm

and would absorb more power, via the altenato

How would it absorb more power? to me the alternator has less drag than the water pump?

Post Wed Jun 15, 2005 12:51 am

Martinaston wrote:Brian
The pump in the hose you have, is it BMW ?
If so have you got a part number please ?

The pump is a standard fitting on this M54 from a 2000 525i touring,but I can't find it on the ETK

Post Wed Jun 15, 2005 12:55 am

Gwynleym10 wrote:
and would absorb more power, via the altenato
How would it absorb more power? to me the alternator has less drag than the water pump?

Basic physics. Pump driven by motor, high losses turning electricity into rotational motion. More losses turning rotational motion of engine into electricity by altenator. Therefore much more efficient to couple rotational motion of engine directly to water pump.

Post Wed Jun 15, 2005 12:58 am

The M54 comes with a belt driven pump but on this page what is the mysterious part at the bottom ?
http://www.realoem.com/bmw/showparts.do ... g=11&fg=35

Post Wed Jun 15, 2005 8:45 am

That's the pump on mine.

Post Wed Jun 15, 2005 2:06 pm

I can't find a number for it.

Anyone ?

Post Wed Jun 15, 2005 4:06 pm

Would guess that this is it.

64 11 8 381 989 Additional Water Pump.

Apparently used on the the E38 728i and most E39s.

Post Wed Jun 15, 2005 4:15 pm

jmc.

Now, any ideas as to how it would run ? temp/time switch, both ?

Post Wed Jun 15, 2005 4:29 pm

Not a clue how the BMW one works.

From what Ive heard about the Vaux ones, they are switched on by a thermo switch in the rad, but they dont normally run on after the ignition is switched off.
The guys who have done the Astra V6 conversion, remove the switched live for the pump and fan, and give them a permanant live so they will run on, untill the water temp drops.

Post Wed Jun 15, 2005 4:58 pm

So would the best place to fit it be hose number 7 ?
Any ideas?
http://www.realoem.com/bmw/showparts.do ... g=11&fg=35

Post Wed Jun 15, 2005 5:38 pm

TBH I dont know how it would be plumbed in.
Looking at the ETK, the M54 seems to have it in a pipe connected to the expansion tank. Maybe Brian can tell us more when he has had a better look.

When I get the V6 out of the Calibra I will be able to see better what Vaux have done.

Post Wed Jun 15, 2005 11:15 pm

The pump is plumbed to suck from the header tank (which has two bottom connections, and feeds a pipe which goes up behind the oil filter housing in the general direction of the main water pump. Can't see where it connects.
The other hose from the header tank had been disconnected by whoever removed the engine from the wreck, but it is a very long hose. Long enough to go the full length of the engine bay. Heater?

Post Wed Jun 15, 2005 11:37 pm

I'm pretty sure that some e30's may even have had additional electrical pumps, sure i saw it on the etk once. Also think some of the US guys talked about them. Was only in hotter climates though.
Can't see it on thte online ETK though...

Post Thu Jul 07, 2005 12:05 pm

Sorry this took so long.

The electric water pump on the Calibra looks the same as this one on the BMW ETK, part number 4.

I found this listed for the E30, but there is no part number for any E30 model that I can find.

So, the Calibra pump is plumbed into the radiator only. There is one pipe near to the top on one side and the other pipe is at the bottom on the otherside of the rad. I dont have a picture at the moment, but will try to get one later today.

I dont know how this set up works, but it must be enough to circulate the water from the heads (its a V6) to the rad for cooling by the electric fan??

Post Thu Jul 07, 2005 12:32 pm

Thanks for the pic JMC
The only way i can think of plumbing it in would involve a heater switch so that the pipe is closed under normal running conditions so as not to compromise the existing cooling system.

This is just so the pump would run once the engine is off to stop heat soak.

If your thinking of running it instead of the existing pump then you would have to do it a different way.

Post Fri Jul 08, 2005 6:03 pm

No, the electric pump is just an auxilary pump to aid cooling after the switch off.

On the vauxhalls, the electric pump circulates the hot water from the top of the rad to the bottom, to improve the efficiency of the rad. You would only have natural circulation without it, so it will take longer to cool down (electric fan will run longer).
Obviously vaux thought the water needed to be moved around in the rad with the fan running, to prevent hot water rising to the top and going out the top hose.
It was all in a bid to stop the rear head on the V6 from cooking itself after switch off.

I havent really loooked into yet, but there must be a way of plumbing into the BMs, like the M54 motor has.