hey-

i was lookin at getting a new water pump and was wondering about your guys input about running electric pumps. i was looking at running an electric pump to help keep my 406 cool at idle or in traffic. i have seen some of the pros and cons of running electric pumps but am unsure of the facts. i was just wondering what you guys had to say and whether or not they are worth the extra cost. i was planning on putting in a new heavy duty radiator also.

-mark

i believe that mechanical water pumps have better cooling ability than electric ones, or at least the low buck to budget electric pumps

If a engine is really detrimental to water temp for performance i belive the good might outweigh the bad if a mechanical pump was used over a electric one, also mechanical pumps can just be slowed down with a larger pulley so they dont create so much drag

I also think that a electric pump as not much of a street item but some others may disagree

i believe that they are other things on the front of the engine to eliminate first to look for power other than the water pump but i may just be old school

electric water pumps cool better at idle..they cool as if the motor is running at 3500 rpm without the extra heat..more coolant flow..therefore there's more flow all the time..the new pumps by CSI(now CSR) or Mezier are extremely street worthy..they are good for about 3000hours..then you send them in for a rebuild which is usually less than 1/2 the purchase price...it's an excellent way to help clean up the front of the motor..the hp savings isn't much unless it's an all out race car..

just make sure on the installation you use a good quality relay and make sure you have it come on with key on/run...keep it off a switch as you just might forget to turn it on...

I've been running one on my '97 T/A since '99..had it rebuilt last year..

one other item to consider on an automatic car is to separate the trans cooler from the radiator..(most all trans companies recommend this)get the largest trans cooler you can get to fit and maybe even a cooler fan if it's a high stall setup...

also...ceramic coatings on the headers are worth a "bunch" and a cowl hood just to get the heat out..

good luck!

Matt

In the past electric pumps were only thought of as race items and not dependable for street.The worst thing that can happen with a mechanical pump is the seal will go and you will find leakage through the weep hole. If this is not caught in time it could ruin the bearings in the pump and cause the drive shaft to fracture from vibration. I had this happen once but the engine was rebuilt and the stock pump was reused. I think it had about 150 k miles on it so this issint gooing to happen right away. You can imagine the reasults but at least I found out what my vibration was. There have ben some dyno testings done on electric pumps  lately to prove reliabilty . I still dont know. You can buy a kit to put a round piece of metal behind the impeller of a stock pump to stop cavitation . Moroso makes sauch a kit and the reasults are substantial. The thing I am thinkng is this may only help at high rpm. Most high volume pumps come wth this allready. That may be all you get wth a high volume pump unless you need the looks of  polished or chrome.  Did you use gaskets with steam holes? And did you drill the holes in the heads if u used non 400 heads?  

If all this engine does is race, then an electric pump is a good addition depending on the type of racing. For a drag only engine an electric pump can free up some crankshaft horsepower by operating from the battery for the duration of the run(s). For a circle track engine an inline pump to augment the belt driven pump can be a benefit under a yellow or red flag to keep a greater amount of coolant flowing through the hot engine than the belt driven pump can at low speed or idle conditions. This keeps the coolant from being puked. 

There are a couple problems with an electric pump in a street driven vehicle. First, it doesn't save any power. The engine requires X- amount of coolant, whether the power to move that amount of coolant comes from a belt driven pump or an electric pump it doesn't matter to the crankshaft. The only place X amount of power can come from on the street is either directly from the crank to the pump; or indirectly from the crank to the alternator through the electrical system to the pump. The power loss is about the same, probably a little more loss going through the alternator as now you have to factor in the efficiency losses of the alternator and electrial circuits. There is another buried problem in here which is without a speed modulated pump there is too much low speed flow, so you loss more power at lower speeds and tend to overpressurize the cooling system which blows coolant into the overflow tank.  The other problem for a street driven vehicle is that you've added another failure path. Instead of a simple belt turning a shaft with a seal, now you've added to that an alternator, fuses, switches, relays, wiring, and a motor.  For the street where relability and repairability are of significant importance, this just doesn't make sense or cents, especailly when you realize there is no crankshaft power savings on the street. The power to run this thing isn't free, it all comes off the crankshaft no matter what form the energy takes.

Bogie

Mark,

As the other guys said..they have no experience in running electric pumps..therefore you only have their inexperienced opinions..what I am telling you is... I have, as have several of my buddies run them on the street for years...these are not cruise night only vehicles..these cars are street/strip cars...Hot Rod power Tour long haulers and daily(fair weather) drivers..these are 8, 9 and 10 second cars..nitrous..turbo-combos..

so what I'm telling you  is you can take it to the bank..your car will run cooler at idle as there is more flow at idle with an electric pump...and you won't lose any horsepower with an 8 amp draw on your alternator either..

just thought I'd clarify that..

good luck!

Matt

Bogie's facts still stand correct...

a engine doesnt need all of that coolant flow at idle, im easily convinced of that since Bogie is not the only person ive heard this from, as for a street vehicle i see the mechanical pump as the better solution

IMO-Form follows function

The factory spent millions to make a system to work in desert heat and snow cold for mile after mile. I find it works the best when it comes to cooling your car, but, when it comes to hot rods, I like electric water pumps and electric fans. The stock clutch fan with a stock water pump and shroud cools better than any other set I have used. It's draw backs are the fan or pieces of it going through the hood when a blade breaks, the belts twisting or just flying off during an 8500 rpm shifts, and not being able to cool it without the motor running. The electric combo address this and if you give up a slight bit of cooling but make it up in versatility, then use the electric set up. I have used it on a car that drove 30 miles to the track and many cruises with no problems. If it got to hot at the track it could sit there and cool itself off without the motor running. I found it to work well for a street/strip car. If you want to slow the water pump and fans down, use a ballast resister and a 3 way switch and you have a high and low setup on your water pump or electric fan. They also make a tic toc, that turns the pump off, and runs the fan, and then turns the fans off and runs the pump, and again continues this to lower the temp more effectively.

BTW-when you run a stock pump with an electric motor to run it, this motor is not meant for continuous use and could burn out, plus it runs at a lower speeds and does not cool well at above idle requirements.

oldBogie
You make the assumption incorrectly that the electric water pump is no more efficient in its use of power than the manual pump.
Let’s just consider that there is torque resistance during acceleration with a Mechanical pump much like trying to walk in a pool of water. If you walk at a constant speed, you will do ok going along with the flow of the water, but the water in your cooling system is always surging up and down with the acceleration and slowing of your driving. Basically you have a water brake resisting your crank every time you accelerate. With an electric pump you have a constant speed that does not drag on your crank up and down as you drive.
Just in this, you have a more efficient way to push water than dragging a belt across a pump.
In your mind, an electric cooling fan would not be any more efficient than a Mechanical fan on the front of your engine. Everyone knows this is not true. Look at production cars currently being made and sold today. Most have electric fans. They do not cause the same pull on the engine during acceleration, and they only run when they are needed. You have to prove to me that there is an exact 1 to 1 comparison between power los during city driving, (up and down constantly) between an electric pump, and my CSR. I have seen the Gas Mileage increase, and my engine never gets HOT.


? The engine is a  mild  383 (6.27 liter)  
? (5.7 liter-350 cu in block, with 4.030 bore and 3.750 in stroke)
? Using a new stand alone TPI harness, without the EGR, or VATS.
? It uses VSS, and 3 wire O2 sensors.
? The Engine has 10-1 compression
? MAHLE forged pistons flat tops  SBC-425030F05.
? Eagle 5.7 H-Beam Connecting Rods
? Forged Summit One Piece Rear 383 Crank
? AFR 195 cylinder heads part #1036
? 1 5/8 in headers.
? Comp Cams  08-467-8 cam, 280XFI HR13
? Intake Duration 280,
? Exhaust Duration 288
? Intake @ .050 230
? Exhaust @ .050 236
? Valve lift intake .576
? Valve lift exhaust .570  
? Lobe Angle 113°
? Hydraulic Roller Lifters
? The intake is a Holley Stealth Ram, Twin 58mm BBK Throttle Body.
? Fuel is delivered through 30# Holley injectors
? The throttle body is a BBK twin 58mm
? Air is routed through a 4” Cold Air tube force fed from the lower grill
? The  computer is a 730 Camaro Computer
? The Distributor is a MSD HEI small cap with Remote coil because of Clearance issues on the Camaro Firewall.
? The Transmission is a 4 speed Muncie Transmission.
? CSI Electric Water Pump
? 100amp Alternator
? The 12 bolt rear end is 3.73
? The tires are 225/60VR15