Crossflow Waterpump? Eh?

[steve bain]

evening. so went for a little whizz earlier now the beast is mot'ed taxed and insured geddon.

anyway, started overheating. crept home and investigated and found the electric water pump has had its day and died.

this got me thinking. why on earth is there an electric water pump? surely the engine has one? is this a fudge someone has done to save having to replace the waterpump? it looks like a recent addition and not from the original build.

any pointers appreciated,

1.6 crossflow in SE.

Steve

[steve bain]

should also add previous owner was not too clued up to fixing cars but liked to try. also, full service inc new plugs and balanced he carbs. it frickin goes like stink! I can't wait to get it rolling roaded on sat

[steve bain]

this is whats on it now

http://www.ebay.co.uk/itm/Kit-Car-Electric-Water-Pump-/220824108615?pt=UK_Motorcycle_Parts&hash=item336a247e47#ht_1442wt_905

anyway i have bought a new xflow waterpump which should be up to the job!

[HoraceM]

I think that you'll find that the electric water pump is the best way forward, with or without a belt driven pump, as these cast iron lumps are all very well when going forwards, but are a bit marginal on cooling when coming into some traffic after a blast - the electric pumps just pump all the time as needed by the heat in the engine.

HoraceM

[Geoff101]

I don't have any cooling problems on my crossflow with the standard pump.

[Paul D Turner]

Mechanical pumps are just fine, Ford made millions of cars fitted with them, I used one for more miles than I car to remember on pre-x/flows and x/flows. The electrical pumps are most useful on track cars where you can run them after you have turned off the engine to keep the coolant circulating or where there is no room for belts etc.

[Terry Everall]

I liked the ebay ad

Good pic of me in the 1548cc Busa at a Sprint!

[steve bain]

well i have fitted a brand new mechanical pump and thermostat (which was missing, i believe so the electric pump works) and it all seems fine now. hmm. bit odd, but there ya go.

[Terry Everall]

Its usual to remove the thermostat so that the electric pump can work correctly and not try pumping against a closed stat

[Adiebee]

hi, replacing the mechanical pump with an electric pump and decent controller can give you upto an extra 10% power increase at the flywheel as you aren't using engine power driving a pump.

[Geoff101]

hi, replacing the mechanical pump with an electric pump and decent controller can give you upto an extra 10% power increase at the flywheel as you aren't using engine power driving a pump.

Really? Where does the electricity to drive the electric pump come from then unless you plug your car in every night to charge the battery?

[Meakin]

AFAIK Adie is correct you do get a BHP increase with electric pump but there is a drag increase on the alternator for the extra leccy needed but its not as much. 10% might be a bit of an over-estimate I would have thought. Anyway my understanding (as Horace and Paul have said) is that the biggest advantage of electric water pump is that the engine can be cooled at a rate compared to the temp of the water not the speed of the engine. ie if you're stuck in traffic on tick-over then the electric pump will produce a better flow rate than the mechanical therefore protecting the engine. Also if used with a timer they can continue to spin after the engine is turned off.

My M100 Elan did this, most odd hearing the fan and also a motor running when you walk away from the car.

Saying that for a normal road car mechanical should be fine.

Paul

[Dave Eastwood (Gadgetman) - Club Chairman]

With managed alternators it's possible to program the controllers/engine management systems to give a "push to overtake" style burst of power mode where all the parasitic electrical loads like this are briefly reduced or removed completely. So the pump, if running would only be running on battery for a few moments, then as soon as you lift off, the charging circuit cuts back in.

[Geoff101]

With managed alternators it's possible to program the controllers/engine management systems to give a "push to overtake" style burst of power mode where all the parasitic electrical loads like this are briefly reduced or removed completely. So the pump, if running would only be running on battery for a few moments, then as soon as you lift off, the charging circuit cuts back in.

But realistically, most people aren't going to have that so the engine is still powering the pump via the alternator and whilst this may (I've no idea) be more efficient than the directly engine driven pump, I'd be amazed if it gives you 10%. My engine's not that powerful but if I could have an extra 12bhp for the price of an electric pump, I'll have one. I can see that at high revs it might help.

Also, can you remove enough parts of the mechanical pump to offset the added weight of the electric pump and controller?

[Meakin]

I agree with you Geoff I think 10% is one the "manufacturers claims" just like you get from exhausts etc. ie pinch bucket of salt needed.

I don't know how heavy they are. I was thinking of having one when I convert to zetec as I wil have to swap the 2.0l water pump for 1.8 one anyway may be worth just removing the impella and going electric and sticking with my escort? radiator. Not sure how much worse the cooling would be with the impela going backwards or if I manage to get it going the right way round might not bother with electrical at all.

As I say its more the stopping or slow traffic situation after a blat that I find heats up more than high speed as you get the air flow.