Electric Water Pump

[nesman 0]

I currently have the '6' conversion in my 309 and was thinkin of fitting a electric water pump, has this ever been done?

A just want it has a backup incase water pump goes. Isit worth really worth it?

[boombang 2]

Unless you are racing, heavily tracking or really tuning the engine, I wouldn't bother. Standard engines don't need them, and a 306 is heavier than a 309 so the engine in normally road use will be doing less work.

 

You say about putting it in as a backup, but depending on your installation couldn't an additional component mean a failure is MORE likely?

 

K.I.S.S. springs to mind.

[pug_ham 244 3 Cars]

If the standard water pump goes then it'll most likely show itself by leaking coolant so an electric water pump will only pump the water out through the dead pump under pressure faster.

 

Not worth it for a road going car like Alex says though imo.

 

Graham.

[BERTMAN 40 1 Cars]

i can see the benifits... car warms up quicker, and apparently water pumps can use upto 3Kw of energy, so theres a saving to be made there. I dont however see the point of using it as a backup though.

[hcmini1989 16]

i can see the benifits... car warms up quicker, and apparently water pumps can use upto 3Kw of energy, so theres a saving to be made there. I dont however see the point of using it as a backup though.

Depends how much load the electric one puts on the alternator ,Could be worse off ? .Plus the mechanical ones tend to keep pumping even when on there last legs i cant see an electric one doing it more than likely just pack up.

[large 33]

Depends how much load the electric one puts on the alternator ,Could be worse off ?

 

TBH I can't see it pulling 250 amps.

 

But as said, no point in this at all.

[Cameron 16]

I've got an EWP fitted to my engine, but I've done it in place of the original water pump using a shorter timing belt and a blanking plate. See my project thread in trackday prep if you want more info.

[BERTMAN 40 1 Cars]

well modern car manufacturers are changing to it for a reason, and it sure isnt because its cheaper! I dont know exactly how much energy a water pump uses, but its definently a waste of energy when your warming the car up.

[hcmini1989 16]

well modern car manufacturers are changing to it for a reason, and it sure isnt because its cheaper! I dont know exactly how much energy a water pump uses, but its definently a waste of energy when your warming the car up.

What cars have these fitted as standard? .And good point about the warming up .

 

Oh and might not pull 250amp but what i was refering to was the load it puts on the alternator could use more energy than what the cambelt uses to turn the pump

Edited November 13, 2010 by hcmini1989

[craig_007 1]

My RS4 has it and so did my old S3.

 

Led to believe old vauxhall carletons and some BMW 320's also

[large 33]

Oh and might not pull 250amp but what i was refering to was the load it puts on the alternator could use more energy than what the cambelt uses to turn the pump

 

I may have got the wrong end of the stick. I have taken bertman to be saying that mechanical water pumps can use 3KW of energy from the engine.

 

For an electrical water pump to use 3KW it would have to pull @12V 250A, @14V about 210A. An electric water pump on a car is not going to use that sort of power.

 

A big electric pump will pull 10A max, so at 14.4v it is going to be 144W that is a lot less than the 3000W a mechanical pump uses.

[hcmini1989 16]

I may have got the wrong end of the stick. I have taken bertman to be saying that mechanical water pumps can use 3KW of energy from the engine.

 

For an electrical water pump to use 3KW it would have to pull @12V 250A, @14V about 210A. An electric water pump on a car is not going to use that sort of power.

 

A big electric pump will pull 10A max, so at 14.4v it is going to be 144W that is a lot less than the 3000W a mechanical pump uses.

 

I didnt look into it that deep mate so i stand corrected .

[Cameron 16]

The benefit of an EWP is more that it's much more efficient, as the flow rate is controlled according to temperature rather than engine speed. With a belt-driven pump you have little flow at low engine speeds and loads at high engine speeds, which is basically the total opposite of what you need! At high engine speeds (and therefore higher vehicle speed) you need less flow as you've got a large volume of air passing through the radiator, at low vehicle speeds or at stand-still you don't get air passing through so you need a higher coolant flow and a cooling fan.

 

So it's worth doing, but not just for horsepower gains.

[EdCherry 34 1 Cars]

What cameron stated really, also useful for warning and cooling of the engine before and after outings.

[large 33]

I didnt look into it that deep mate so i stand corrected .

 

The joys of working nights

[Cameron 16]

I'm glad you did though, good to see it proven!

[large 33]

TBH it is VERY basic and I am not 100% how accurate the 3Kw figure is. But after reading your earlier post I cant see how car manufactures have not switched to them years ago.

 

But i stand by my original comment that it is not worth retro fitting on on a road car.

[welshpug 1,661]

reliability perchance?

[Cameron 16]

My EWP pump runs off a 10A fuse, so let's say if the alternator is only 75% efficient, it will only take 0.2kW of power to run the pump at full capacity.

Edited November 13, 2010 by Cameron

[BERTMAN 40 1 Cars]

tbh im not too sure how accurate the 3KW is, but thats what my engine design lecturer keeps telling me, and he seems to know his stuff. Ive been thinking about retro fitting it onto one of my cars, to see if it makes much of a difference. I think ill have to have a little look at Camerons thread

[large 33]

reliability perchance?

 

30 years ago maybe. The only benefit i can see is that if the engine is running so is the water pump.