Found nothing on a search of the tech forum.....so......

Obviously the less parasitic drag you can remove, the more real HP gets sent back to the rear wheels.

A car without AC, PS, and PB, is what I will have......and now I am contemplating electric water pumps to end up with just one drive belt for the alternator.

Upsides, downsides, anyone here use them on the street ?

The only issue I see is that they are time limited.......so I'd probably have to replace it every 3-4 years if I drove 2 hours a day. One example is shown below.....but many places make them.

http://www.meziere.com/displaycatego...id=244,232,388

 

Let me save you a lot of time and trouble, and I bet set off yet another huge debate by the perpetual motion and free energy crowd.

The stock pump takes around 1-2HP to turn. The drive belt and pulley is about 97% efficient. That's it- that's all there is to possibly gain even if there was no pump at all.

An electric pump consumes electricity produced (inefficiently) by the alternator, it doesn't run for free.

It makes more sense to drive a pump directly by a pulley and belt than to drive an alternator (driven by a pulley and belt) which produces electrical energy sent to a motor which converts the electricity back to motion.

 

Electric water pumps are good on drag racing cars, use electric fan and pump and cool the motor between runs, also run directly off the battery which has your charger connected to it between rounds

 

Thank you for the replies........a belt driven water pump it is.......the HP loss isn't significant enough to warrant the expense......and I won't be hitting the dragstrip.

The avoidance of AC, PS, and PB, is more from a purely functional point of view than a HP one, which is just a side benefit.......less weight, more tactile steering and pedal feel and no leaking hoses, or PS rams crapping out (which happened to me on my 74 and was damn scary when the steering locked) etc.........

 

WOW! Mike and I agree again, I use nothing but Edelbrock pumps on my Vettes. I do use a 1:1 crank/water pump pulley ratio rahter than the 15% overdrive that was OEM on my LT-1's. I rev the P*SS out of my motors, to 7500RPM so 1:1 works for me. Canton makes a decent crank pulley that lines up to the Chevy pulleys.

Electric pump, leave that to the bracket racers. I wouldn't want to drive far from home depending on that set-up.

 

Although I have no realistic way of proving it, I have a sneaking suspicion that an electric pump would cause a net DECREASE in HP over a conventional belt driven pump.

There's nothing miraculous or mysterious about an electric pump- it doesn't have some super zoomy impeller or housing that allows it to move coolant more efficiently than a mechanical pump. Either type still takes X amount of HP to do the job properly. This job includes having the ability to move sufficient coolant under the most demanding circumstances- which is an extremely hot engine sitting at idle. I know that the stock GM pump has a minimum of approx. 35% excess capacity for this very reason, but don't know about the electrics other than some guys state that they have run them on the street with no overheating problems.

I'll therefore give the electric pumps benefit of the doubt and presume that they have adequate excess capacity also. That means that each takes the same amount of HP to do the same work.

As stated above, belts and pulleys are around 97% efficient. Car alternators are not, nor are electric motors. Alternators are usually 50-60% efficient due to heat generation, mechanical losses in the bearings and drag from the cooling fan. Small electric motors are better for similar reasons but are still only around 75%ish.

With this line of thinking, you'll LOOSE HP by using an electric pump.

 

I tend to agree, seems the addition of a pulley for the WP will be of little to no significance overall, as the energy required to pump the water, either from the additional alternator drag when using an electric pump, or the drag from the mechanical pump will be equal, more or less.......and in the scheme of things perhaps irrelevant % wise on a 650+ HP engine. Not looking for the last 1/10 of a second, just curious as the product is out there.....

 

with everyone above.

If you have enough cash, buy an aluminum waterpump instead of a cast iron one to save weight.
Most electric water pumps won't last very long on the street. And assuming you could gain some HP, it would be negligible.
Keep the extra money for more useful stuff, like heads, intake manifold, headers...

 

All one needs on these cars are stock GM pumps though it probably would be a good idea to change it every 25 years or so.

 

There are many advantages to the electric water pump not the least of which is HP. It may be correct that a belt driven water pump may only take 1-2 HP at idle, but it takes a lot more to push that thing when driving 3500 rpm on the highway. An electric pump is always spinning at its’ efficiency rpm not a wildly inefficient speed with the engine. Also in traffic when you need your cooling the most your antiquated mechanical pump and fans are moving the least amount of air and water across the radiator. An electric set up is running at its’ best in traffic when you car needs it the most.

I have had an electric water pump and fans for that last couple of years. I like to auto-x and in between runs may engine cools down fast. I drive in traffic all the time without any fluctuations in temp, my car takes less time to get up to temperature because my electric water pump is on thermal switch.

 

I'm running an electric water pump and I love it. With the electric water pump, electric fans, and electric fuel pump, I upgraded to a CS130 alternator and serpentine belt. Love them too.
Bee Jay

 

Well dang Hauq`, you and Bee Jay just brought some real world facts into this little debate that seems to have been based on some, to quote "I can't realistically prove..." arguments.

 

Uhhh, no. That 1-2 HP at engine red line. And that's a fact- straight from GM.

 

Dyno tests from Car Craft (May 2000)

No fan = 496hp
Electric = 494hp
Thermal clutch = 487hp
Nonthermal clutch = 485hp
HD thermal = 476hp
HP flex fan = 476hp
Stock 4 blade = 473hp
Low-profile flex = 466hp
One piece plastic flex = 460hp
OE replacement 6 blade = 449hp


I use the one of GM's over 30 different thermal clutches (they all have different ratings).
I do use an electric pusher fan, on with a/c to increase air flow.

A friend of mine has been using an electric water pump in a sbc Fiero for over 6 years with no problems, but it also came oem with electric fans.

 

Oh please don't use the word "arguments" in an electric water pump thread. Some very passionate feelings both way here on the forum. I like my electric water pump. It does a good job of cooling my car, I can switch it on between autocross runs, and it has been very reliable. I had an aluminum water pump for over 20 years before that and it also did a good job. I'm not afraid to try something new on my car and if it doesn't work out, I'd say so. This electric water pump has worked out wonderfully. I didn't do it for the horsepower advantages.
Bee Jay

 

 

I've been running a Meziere on my Camaro (LT1) for a little over 7 years and about 37,000 miles. It hasn't yet needed replacing and runs cool as a cucumber with the AC on in FL heat. No regrets.

 

Everybody's right here, it just depends what you value. The electric pump is clearly less efficient as anything with more steps to the energy transfer will be. (see: hydrogen fuel cell cars...) However even if it is about half as efficient, as the numbers approximated above would call it, that's still only 2-4hp compared to 1-2hp losses. Essentially negligible in either case. As seen above the choice of fan has a much, much larger impact.

The ability to decouple engine and pump speed seems like a great benefit, both between runs racing and in traffic for practical street use. Of course factory belt driven pumps are going to be "good enough" for most factory-like setups. You have to have the desire or need to justify the extra expenditure.

Personally, I just bought a car for regular driving with a Meziere electric pump on its ~550hp engine. So far so good but it's still wet behind the ears. The engine is controlled by an Accel Gen 7 DFI system which also manages the water pump and electric fan, so it's nice to have all of that under the same roof.

 

i take the chance, sorry if a little OT.

which the power loss with an OEM 5 blade and thermal clutch not engaged?

 

Original fan clutch, 1-3HP. New style repro, maybe 5HP AT ENGINE REDLINE, for the benefit of the I-believe-in-miracles crowd