Electric Water Pump Drive

http://store.summitracing.com/partdetail.asp?part=MRG-4333&autoview=sku

I saw these a few days ago and was looking at it for my car but rather not 'test' it on my daily driver. My girlfriends cherokee doens't get driven all that much, and is 95% around town in stop and go. I've read on other forums this is great for idle speeds and the fact you can wire it to run for however long you want after the car is off to help it cool down afterwards. I'm not sure how good it would do at highway speeds though, but the cherokee has such a low coolant capacity that moving it through the system may not be an issue. I also read that the cooling system is "too efficient", and moves it too fast through the radiator.

Opinions?

edit: this probably should go in 'modified' section. Also bypassing the mechanical water pump drive will free up a few hp.

Re: Electric drive water pump??

You mind as well go electric fans instead of an electric water pump. The water pump pully is so easy to turn by hand. The only thing that really is a drag on the motor is the clutch fan.

Re: Electric drive water pump??

Not "too efficient", too fast. I'd be very interested in converting to an electric pump but I'm not sure how that particular kit would work on an XJ. I'd be more interested in a completely external pump, not just motor, and make a bypass "housing" for the old non-existent pump. The possibilities for it are vast though, you could program it to run at a more favorable speed or variable speeds depending on engine speed and/or temperature and what not.

Re: Electric drive water pump??

Blaine the main intention wasn't for power (that was my intention on my M roadster though ), but any extra power is nice.

Purple, thats what I meant. I believe it runs at 1500 rpm, which is roughly what the motor runs at at cruising speed, correct (I dont have a tach in mine) but then at stop lights would cycle more through the engine and cool it down faster. and have it run for a minute or two after the engine is shut down to cool it quickly

Re: Electric drive water pump??

I'm not really sure why you'd want it to cool down quickly though. If it's running with no problem at operating temperature then if anything you'd want it to stay at operating temperature for as long as possible so it doesn't have to warm up every time you stop for 30 minutes, costing you gas mileage. Same thing with cooling down at stop lights, idealy, you wouldn't want it to NEED to have to cool down at stoplights. Unless you meant in order to compensate for its tendency to heat up stopped rather than with lots of air flowing through the radiator in which case yes, you would want the cooling system to run more efficiently when stopped but that doesn't necessarily mean that it will run faster, as you said before too fast can be a bad thing. Also, how would the pump differentiate between coasting, and stopped without using the speedo? Just some question you need to think about

Re: Electric drive water pump??

Just with lots of stop and go the needle creeps up and it scares me, I've had it get too close to red and the bottle overflow wayy too many times in the couple of months that I've owned it.

Re: Electric drive water pump??

Around town accelerating at a usual pace it will usually get up to 1200 rpm and then shift to second...

So that water pump will be flowing alot more than stock.

Re: Electric drive water pump??

In my experience it isn't the water flow rate that kills you, it is the lack of air flow thru the rad. Stop and go = not much air = not much cooling.

Re: Electric drive water pump??

I'd skip the electric water pump. You don't get very much power gain, if any at all. The drag produced by the water pump is so insignificant that the increased load on the alternator needing to run the electric pump will probably be just as much or more than the mechanical pump generates.

As for overheating, do the Ford Taurus electric fan swap, or just get rid of the clutch fan and go with two electrics. And make sure that your radiator is clean/ How long has it been since you have done a coolant flush? Or ran water through the radiator fins? Off roading puts debris (dust/mud) inbetween the fins and blocks airflow. Even if it is a daily driver, road grime and road dirt will get up in there. Powersteerng fluid leaks or any other oil makes dirst stick to everything.

You might try putting in a cooler thermostat too. Like a 165* vs. a 180* or 195*.

The radiator was pulled off another xj (switched to open cooling) before I even bought our xj, and cleaned. Then I just flushed the system a week or 2 ago when replacing the water pump. The car runs fine, but theres always room for improvement. Again, I wasn't looking for the HP gain, just upping the reliability some. I'll skip it after all the comments, thanks for your input

Re: Electric drive water pump??

IRPancake said:

Just with lots of stop and go the needle creeps up and it scares me, I've had it get too close to red and the bottle overflow wayy too many times in the couple of months that I've owned it.

Click to expand...

Yeah, if thats your issue, you have other problems to worry about.

I did the GoJeep cutting board restricter mod.
slows the coolant flow down at the upper rad hose... much better cooling, and even with a weak old tuarus fan on low (they are strong, this one is on last legs, howling)
I have not had an overheating problem since.

Have you noticed any difference in your HEAT using the restrictor mod? Methinks since it would restrict flow to the radiator more coolant would end up through the heater core...

Also if you are thinking than an electrical water pump would be more reliable than belt driven, alot would argue that...a new belt driven water pump is argued to be more reliable, as long as your serp belt does not break.

Of course I still switched over to electric fans, the same could be said about the stock mechanical fan being more reliable than an electric fan.

http://store.summitracing.com/egnse...&Ntk=KeywordSearch&DDS=1&N=700+4294924500+115

cheap restrictors. they usually come in packs of 3 or 4.

swap'em until you get the right amount of heat vs. the desired engine temp.

while we're on the slightly off topic, are there any OEM electric fans from vehicles that will replace the clutch fan?

taurus fan

I figured thats what was mentioned earlier but just wanted to ask, I'll search before asking more stupid questions

MMMMMM roadster :worship: (although I prefer the coupe). I'll be shopping for a 95 Avus Blue M3 this spring(insert fingers crossed smiley here). I removed the mech fan and added a 2nd stock e-fan(97+ w/ 10 s-blades), pounded out the mech shaft, used a shorter belt(2045mm) and went directly from the hb to the alt. Not a stupid question, btw.

gradon said:

MMMMMM roadster :worship: (although I prefer the coupe). I'll be shopping for a 95 Avus Blue M3 this spring(insert fingers crossed smiley here). I removed the mech fan and added a 2nd stock e-fan(97+ w/ 10 s-blades), pounded out the mech shaft, used a shorter belt(2045mm) and went directly from the hb to the alt. Not a stupid question, btw.

Click to expand...

At first I wanted a coupe too, but only for the rarity and just how wierd it looks. I've fallen in love with the roadster now over the coupe though, plus it weighs less, and the coupe can't put the top down Love the m3 too (same engine), its just less emissions stuff on the obd1's right? Not that a sports car is built for straight line, but I should be hitting low 13's in the 1/4, I think with a really good driver (ie: not me) it could be 13 flat. When I get a better job and can afford new tires however often, I'm going to be autocrossing it too.

I'm not really sure why you'd want it to cool down quickly though.
===================================
A few cars have a BIG problem with key off peculations. General cars with very large motors and tight engine compartments that are shut down right after a hard run or towing. But a fan that runs on after key off will cool the rad often eliminating this problem. It will also keep the engine compartment temp down saving hood paint belts wires etc. Just letting the engine idle for a few minutes before shut down worked too.
The XJ has very little problem with key off perk if the coolant system is right. Small engine, big engine bay promotes good natural air circulation when key off.
I had a small problem with it when towing 4200 lb in 107 deg heat but 2 min idling before key off fixed it,
Saving HP with a E-pump. At very high RPM the engine driven pump can draw a lot of torque, Some say 25 HP or better do to over speeding causing turbulence with in the pump itself. Bad for race cars (high speed ) but all but meaningless for my type of offing. If this top end HP is important to you? You can under drive the pump but this will then suck in low RPM operation. The E-pump/fan would be the answer here.
Some race cars like the fact the engines can be cooled way down quickly after key off with a E-pump/fan and restrictor plate ( no t-stat) Helps keep from burning the pinks on hot engine parts if the engine must be worked on quickly after key off.