electric water pump on magnum motor - belt routing

Has anyone used an electric water pump on a magnum set up that has retained all the accessories? If so, how was it done, extra idler, belt routing, etc? Thanks!

No one has done this huh?

I did a search on a Dakota forum I'm a member with and saw nothing. Another search just showed the people saying electric is not suitable for street. You'll have to go to some forums and really search up the subject. What I did find was from 2012.

Yup, that was what I found. The electric WP will be fine for the street as long as it is not 100 degrees and stuck in traffic, which I don't drive it under those conditions.

Whenever I've been in houston it was always 100 degrees and I was always stuck in traffic, even when I lived there as a kid.


I think if it was a good idea then many manufacturers would be running them, I don't remember seeing them on anything built outside of europe and those are pure garbage.

I did but I don't have powerstering or A/C.

Magnum WPs are reverse rotation. That might limit the market considerably

I don't think they make one for the magnum just the LA. And how would you route the serpentine belt/fan?

The pully systems between the LA motor and the Magnum motor interchange. If you want to use an electric water pump, why not just convert back to the LA pulley system for the accessory drives?

The differences between the "forward rotating water pump and the reverse rotating water pump" is the direction the vanes are angled on the impeller and that difference is simply done because the different pulley systems turned the pump impeller in the other direction. The cooling systems on the motors are both designed to flow the coolant through them in the same direction. The alternator, the power steering pump, and the AC compressor all turn in the same direction on both motors. When Mopar went to the serpentine belt system, changing the direction of the water pump rotation was the most simple way to make it work, and al they had to do then was change the angles of the vanes on the water pump impeller so the coolant would flow through the motor in the correct direction. Modifying just the water pump was the simplest and cheapest way to get the job done.

You guys tend to way over think this stuff.

For the record, there is no way I would exchange a belt driven water pump for an electric driven water pump on a street driven vehicle, but you do you, and I will do me.

My wife's GLE580 uses electric WP and electric AC, matter of fact, electric everything with no belts. Make the "stop" portion of the "start/stop" feature very nice. It has the bi turbo 4.0 integrated with a 48-volt motor-generator that gives it an extra 21 hp and 184 tq. Hardly "pure garbage".

Going from my memory I don't recall anyone back in the day running an electric setup on a 5.9 Magnum. Worse case you could ask on a Dakota RT group or search on www.dakotart.com if that website is compatible with your browser.

Why.

The "Why" is so I can circulate water through the block with my electric fan running to cool the motor down to 150 degrees in about a minute (with the engine off).

I haven't seen anything on those boards as I am members of a few. Most of those are pretty "dead" now.

Is this a race motor? If not to me its a waste of time and money. Good luck on your quest as you most likely are the only one.

It looks like you can simply not route the belt to the water pump. The water pump in the image is just above the crank pulley in the image. What length belt that would be...

It would be spinning the wrong direction.

What would spin in the wrong direction? The water pump would be electric. Am I missing something?

The electric water pump would be for the reverse flow the Magnum uses (vs LA) so that is not an issue. Yes, they do make them specific. My only concern would be that the long routing without any pully/tensioner and throwing the belt at higher RPM's.

No, not a race motor but I do take it to the track a lot.

I mis read what you said. You are right on the routing and finding a shorter belt. Here is a magnum electric pump he could use. Pump

The diagram I posted above includes the tensioner. I don't know why that pic posted sideways, but the tensioner would be at the bottom of the diagram I posted (as viewed above).

Like this.

I meant they will probably need to be a tensioner between the crank and PS and not so sure how easy it would be to fab it.

You cant run two tensioners. . Are you running a/c? Simple test would be to buy a belt and see how it acts. There might be enough tension on the belt with the one stock tensioner.

Not necessarily another tensioner.... Another idler pulley. I tried the AC bypass belt and it throws without an idler pulley on it. To much movement on the belt at 6,200 rpms. And I don't want to get the pump, install it and then find out it wont work without some sort of idler pulley. I was hoping someone had done this already for "proof of concept".

If you are throwing a belt you have something not right. The non a/c configuration is just fine with its one idler and tensioner.

I suspect he is throwing the belt at high rpm because the "wrap" around the power steering pump is not enough, and the space between the two remaining pullies is too long, once you eliminate the trip the belt takes around the water pump. In belt speak, its a long way from the crank pulley to the power steering pulley, and then once you get there you are loosing almost 1/2 the amount of space the belt is riding around that PS pump pulley. The PS pump probably has a pretty big load on it, and then you are going either to the AC pump (another high drag belt driven device) or you traveling all the long free span to the alt. The belt doesn't stand much of a chance. There is too much space between the high draw PS pump and the crank and too much space from the PS pump to the high draw AC or Alt. That space is allowing the belt to flex enough to jump the small ridge that keeps it on the pullies. Once the belt climbs the outer ridge, the tensioner will relieve enough pressure to allow the belt to continue to walk off the pulley, once that belt gets past 1/2 the width of the pulley, its gone, and the tensioner is helping it leave. .

You either need to go back to the V belt two belt system with one belt driving the PS pump and the other driving the AC & alt, or the Alt and an idler/tensioner. Or you need to add an idler to replace the water pump (close to the location of the water pump) with the serpentine belt system.

The way I read it he is trying a shorter belt without the a/c and possibly no idler. If he runs it like the diagram I posted shows he should have no problem. Unless he has the wrong belt.

The way I read it is he wants to eliminate where the belt passes around the water pump and have the belt go directly from the crank pulley to the power steering pump, then to the AC, the tension pulley, then the alt and back to the crank. The shorter non-ac belt allowed him to bypass the water pump pulley and still run the AC, the alt, and the tensioner, but he keeps throwing the short belt at 6280 rpm. The electric water pump is not belt driven, and he does not want to put an idler pulley in place to replace the water pump pulley.

Guess we all need to have the same understanding to be able to help him.

This is for my turbo set up that turns 6,200 - 6,400 rpms. This is what I want: to eliminate where the belt passes around the water pump and have the belt go directly from the crank pulley to the power steering pump, then to the AC, the tension pulley, then the alt and back to the crank.

By bypassing the WP, there will be partial wrap around the PS and crank with the belt having a long span with no device/idler pulley. As straight of alignment as you can possibly get, I believe this will still cause a belt to throw. I will see if I can put an idler pulley some where near the water pump as shown below.

My experience with belts getting thrown is that it happens when you back off the throttle and the pressure is some what off the belt. Causing a kind of loop that flips the belt off.