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Electric Water Pump in subarus?


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Does any one have any experience, knowledge, thoughts on fitting Electric Water Pumps (EWP) into L series (Loyale) engines, like the ones at this link : daviescraig.com.au/main/display.asp?pid=8.

 

It seems like a better idea than removing the engine fan and replacing with a second electric fan, although you could install a second fan as well. Still leaves you with the original thermatic fan and with the controller you can set the temperature of the engine, no searching for lower temperature thermostats. They also report fuel savings of up to 15% at higher speeds. Some drawbacks might be the lack of coolant to heater core reported in some vehicles.:banana:

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How much does something like this cost? I've never used them on cars, although I've thought about it a couple of times.

 

I do know that the current craze in the HVAC industry to increase efficiency is going to variable speed pumps and fans, instead of using constant speed ones and just throttling back on the flow rate by shutting the valve off (which is what a traditional car thermostat does). It looks like the controller for this is a variable speed controller to adjust flowrate to required cooling load, so in theory, it should save a bit of energy.

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262.88 for the water pump kit and 159.00 for the controller at www.spatechnique.com. It seems like a lot of money to me. I guess if you want to squeeze every last ounce of power out of the motor, it might be worth the money. But remember the testing they report on in the linked article is on a Ford V8. You might not experience the same kind of horsepower and economy advantages on a 1.8. The installation does look pretty simple, though. And if the claim of a 2,000 hour life is good, you should be good for 100,000 miles or so, depending on your driving style.

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seems like alot of money for a 3hp gain. Thats the estmate on how much HP it takes to run the cooling system. On the reverse side there is no free ride. How much energy does it take pump?

 

edit (answered my own qyestion) > i did the math.. its life is 100000 miles at 50mph and it uses 0.15 HP to operate. In the next few years OE's will be going to electric waterpumps and electric thermostats. Personally i dont see any advantage to it on a subaru engine. i can see the pros and cons. Beisdes the enigne compartment is tight enough already, where would you put it?Now if you were making a high HP turbo motor, the fact that it can run after shutdown is a huge plus.

 

 

 

 

nipper

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  • 1 month later...

Not as interested in HP gains as in better fuel economy. With a 5% gain from electric fans and a 10-15% gain from a EWP. I could get 10L/100km rather than the current 11-12l/100 km. Petrol in OZ is at about $1.30 a litre. My $50 of petrol only gets me 360km. This would get me about 410km. I calculate this would save about $5-8 per week. At $500 aus to install it would only take a year to pay for itself. I also think that there may be advantages to the cooling system in an older car, as it seems that heat is a major killer of these vehicles. Any extra help with cooling would be great.

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I was thinking about this just today, while daydreaming at work. Then I saw this post...what about a motor that powers a belt and the belt powers your stock water pump? I know there is friction loss between the belt and pulleys and the motor...but what do you think about it?

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If the normal water pump uses say,... 0.2 of a hp to operate. then wont you need a 0.2hp electric motor to do the same job.

So the alternator must produce the electricity to power this 0.2hp motor plus more for heat and noise generated.

 

I cant see how it would be any more effeciant, although i just though of the thing where it can cycle on and off

 

It mite sound a bit pesemistic but i cant see any real gains

 

Gannon.

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And thats the issues that OE has with designing an eletric waterpump for the masses. It would have been easy to do with a 48 volt system, but they have droped that idea due to the cost,weight, and complication of having both a 12 volt and 48 volt system. The cost of development vs the benefits of electric system really doesnt justify it at this time. This is an extreemly critical part, and if they screw it up, well, engines are nt cheap to repalce.

 

 

nipper

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