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E34 (1989 - 1995)

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  #1  
Old 09-25-2012, 11:00 AM
robertobaggio20 robertobaggio20 is offline
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Electrical engine water pump for the e34?

Hi Everyone,

I'm about to replace my water pump (bearing noise), and was wondering if there is such a think as a non-belt driven electrical water pump for the m50 engine. Clearly a modification, just like the clutch fan delete/replaced with an electric engine fan....but is there such a thing? I can't seem to find reliable information, if anyone knows about this and has some views and links etc would be most obliged if you could chime in.

And anyway, is this a Good Thing to do, even if it was available ? Thanks.



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  #2  
Old 09-25-2012, 01:11 PM
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_Ethrty-Andy_ _Ethrty-Andy_ is offline
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not that i know of, but im sure its possible. the main trouble i could see is that it will be less reliable though, and you'd probably have to modify the tensioner to attack the belt at a different angle. could be done for sure, but i dont see the point. why do you ask?
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  #3  
Old 09-25-2012, 02:02 PM
robertobaggio20 robertobaggio20 is offline
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Hi Andy.

I was wondering if an electrical water pump would be less of a drag on the engine, resulting in more power to the wheels. Since I am about the swop out my water pump, was planning on swopping in an electrical one if it made sense.

Would you say that an electric water pump would be less reliable? Why?

What do modern cars come with? I know the electric fan is a standard item, as is the power steering, but what about the water pump for the engine?

The pulley could be removed and a new belt of the appropriate length considering that this pulley is bypassed, could be fitted.
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Old 09-25-2012, 05:10 PM
My525iT My525iT is offline
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I get your drift. But hard to see it making sense on this car. Maybe it is the straight 6 on it.
It would be an interesting calculation.

If you wanted to road test the theory. Take off the AC belt.
It would seem to be a similar equation as it would remove one pulley from the assembly line....
Remember though - you would compare it to the way the car drives with the AC switch off.
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  #5  
Old 09-25-2012, 11:01 PM
robertobaggio20 robertobaggio20 is offline
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Originally Posted by My525iT View Post
I get your drift. But hard to see it making sense on this car. Maybe it is the straight 6 on it.
It would be an interesting calculation.

If you wanted to road test the theory. Take off the AC belt.
It would seem to be a similar equation as it would remove one pulley from the assembly line....
Remember though - you would compare it to the way the car drives with the AC switch off.
Not possible to test the theory using this method. The engine would overheat in 5 minutes due to non-circulation of coolant. I'll need to have the electric pump in place first already. Still don't know if that exists for our car though..
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Old 09-26-2012, 01:40 AM
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Interesting concept but steer clear LOL... Blow a fuse and you could blow your head gasket. That is why it is belt driven... Yes belts can break but thats why we check them often and replace when worn. By eliminating the drag of a water pump pulley you gain very little but stand to lose a great deal.

Actually, I think it's a mute point as no one makes an electric water pump for your M50 for the same reasons suggested above.

Stick with the battle tested, tried and true steel impeller, belt driven water pump. Slides right in, bolts right up for years of joy LOL...
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  #7  
Old 09-26-2012, 02:22 AM
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Quote:
Originally Posted by CarDriver View Post
Interesting concept but steer clear LOL... Blow a fuse and you could blow your head gasket. That is why it is belt driven... Yes belts can break but thats why we check them often and replace when worn. By eliminating the drag of a water pump pulley you gain very little but stand to lose a great deal.
this. the electrical side is what makes them less reliable. that said, late model cars including BMs are electric everything, even the starter motor and alternator are all in one units.

I've been down the road of removing pulleys etc like power steering, its only going to give you literally 1 or 2 hp, its really not worth it given the losses. also, youd have the expence of the electric pup plus modifying it to fit, the issue of sealing it so it doesnt leak, and after all that you would then need to wire up an AUX fan. yes it will give another few HP on the dyno which wont even be noticable in real life, any power gain would be offset by the increased weight.

what My525iT is saying is to take the aircon belt off, and notice the "performance gain". the zircon pump and water pump will have very similar internal friction.

the only point in doing it would be so you can say to people its got elctric waterpump conversion. whoopee lol.
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Old 09-26-2012, 06:54 AM
robertobaggio20 robertobaggio20 is offline
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Thanks guys.....so the electric water pump is out of the window.

How about the fan clutch delete modification? Does it get the engine any more oomph ? Is it more reliable? Do the electric fans last for a lifetime ? Are there certain brands that are considered highly reliable? Is the dual temperature switch necessary...what are the benefits of this?

Does the extra load on the alternator due to its power requirements for the electric fan (an extra 25 amps I believe) lead to more drag on the engine than what is doing away with the fan clutch ?

Expert advise very much appreciated here.


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  #9  
Old 09-27-2012, 12:17 AM
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now your talking. if your car has aircon it will have an aux fan on the other side of the radiator. this is all you will need. the viscous fan is really only there because that was the norm in those days to have that. in the current setup, the aux fan will come on if the radiator gets hot to help the viscous fan. If you are going to do that though, replacing the temp sensor and the resistor pack would be a good idea as you would no longer have a backup plan.
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  #10  
Old 09-27-2012, 12:26 AM
robertobaggio20 robertobaggio20 is offline
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Originally Posted by _Ethrty-Andy_ View Post
now your talking. if your car has aircon it will have an aux fan on the other side of the radiator. this is all you will need. the viscous fan is really only there because that was the norm in those days to have that. in the current setup, the aux fan will come on if the radiator gets hot to help the viscous fan. If you are going to do that though, replacing the temp sensor and the resistor pack would be a good idea as you would no longer have a backup plan.
Are you suggesting that I can take out the fan clutch WITHOUT replacing it with a new electric fan, and only rely on the auxiliary fan located on the outside of the radiator ?

If so, would the presence of the a/c's condensor impede air flow to the radiator proper?

Would this setup work in a situation involving sitting in traffic on a hot day?

Would it be a good idea to simply keep the aux fan's switch permanently jumpered so that its permanently on ?

If I take out the fan clutch and rely 100% on the aux fan for cooling, will it function effectively to cool the engine, even with the air conditioner on?

I have changed the aux fan's resistor before, but not the temp sensor. My observations have been that temperature sensors on the car (including those on the cylinder head) work well despite a light coating of rust, even after all these years, as they contain no moving parts and are made of metal which does not break down. Is it beneficial to do this? Thanks.
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Old 09-27-2012, 12:40 AM
robertobaggio20 robertobaggio20 is offline
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Quote:
Originally Posted by _Ethrty-Andy_ View Post
now your talking. if your car has aircon it will have an aux fan on the other side of the radiator. this is all you will need. the viscous fan is really only there because that was the norm in those days to have that. in the current setup, the aux fan will come on if the radiator gets hot to help the viscous fan. If you are going to do that though, replacing the temp sensor and the resistor pack would be a good idea as you would no longer have a backup plan.
Do you know anyone who has successfully driven with merely the aux fan alone? Have you perchance tried this on your car before? What's the feedback like?
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Old 09-27-2012, 01:56 AM
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yes my M52 E30 was like that. i never installed the viscous fan. also i took it off my 520iT as well. the only reason there is one on my E30 is that there is no aircon in it. all BMWs of this era are the same. do not hardwire the fan to be on as this will maximise cooling even when the car isn't heated up properly. yes the aircon grill will decrease flow slightly, but a pusher fan is FAR more effective than a puller fan anyways
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Last edited by _Ethrty-Andy_; 09-27-2012 at 01:58 AM.
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  #13  
Old 09-27-2012, 06:12 AM
robertobaggio20 robertobaggio20 is offline
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Originally Posted by _Ethrty-Andy_ View Post
yes my M52 E30 was like that. i never installed the viscous fan. also i took it off my 520iT as well. the only reason there is one on my E30 is that there is no aircon in it. all BMWs of this era are the same. do not hardwire the fan to be on as this will maximise cooling even when the car isn't heated up properly. yes the aircon grill will decrease flow slightly, but a pusher fan is FAR more effective than a puller fan anyways
It might be a good idea to use the aux fan as a main engine cooling fan, but still install an electric fan as a backup cooling fan for intense situations ? The "spare" electric fans' circuit can be dovetailed with the aux fan's circuit to be triggered when the temperature is high. What do you think ? The idea of two fans as a backup provides some comfort.
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  #14  
Old 09-27-2012, 07:59 AM
damengoodsman damengoodsman is offline
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It appears that I am a few days late but I still want to chime in on the motor driven water pump idea. The way I see it, an electric motor driving the water pump wont really free up any significant amount of horsepower to the wheels. the only difference between the pump being motor driven or pulley driven is where the power comes from. with a pulley driven pump the power comes from. with a pulley driven system the power comes from the crankshaft via the belt. to switch to motor driven pump would mean the power would come from the alternator (the alternator would have more drag on the engine than before due to increase in electrical demand)which happens to be pulley driven as well. The only power to be gained here is if the motor is more efficient at driving the pump than the pulley (which is likely true as there would be almost no side load on the pump's drive shaft as there would be with a pulley drive) but in this case you are only gaining the difference in efficiency. Of course the alternator may run at higher or lower efficiency at higher loads as well, but either way you are splitting hairs I think.
One place where a motor driven pump would be advantageous is when the engine is cold and little to no coolant flow is required. A controller could send a small amount of voltage to the motor (for a DC motor, an AC motor would be much more expensive and require much more expensive components to control speed) so it would run slowly and would draw less power doing so until the engine started warming up and required more flow. Of course this would require more parts (that could fail) and ultimately who really cares about an extra 1/2 hp to the wheels during warm up?
I think this answers the question that has already been answered above, hopefully i am not overlooking or misunderstanding something that will make a fool out of me..
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Old 09-30-2012, 05:01 PM
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Quote:
Originally Posted by robertobaggio20 View Post
Hi Andy.

I was wondering if an electrical water pump would be less of a drag on the engine, resulting in more power to the wheels. Since I am about the swop out my water pump, was planning on swopping in an electrical one if it made sense. .

Sorry but water pump is probably the most useless and dangerous pulley you can replace to expect 0.1 HP of performance gain. Get underdrive pulley for your power steering if anything.
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Old 09-30-2012, 09:53 PM
robertobaggio20 robertobaggio20 is offline
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Thanks for your responses everyone ! I've done away with the electrical water pump idea and have decided to remove the fan clutch as well and survive on the aux fan. I've been driving with the fan clutch restrained by a spare belt tied between the blades and the intake manifold (the fan just stays there while its pulley spins away as per normal), and have had no overheating issues.
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  #17  
Old 10-01-2012, 01:51 AM
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Quote:
Originally Posted by robertobaggio20 View Post
Thanks for your responses everyone ! I've done away with the electrical water pump idea and have decided to remove the fan clutch as well and survive on the aux fan. I've been driving with the fan clutch restrained by a spare belt tied between the blades and the intake manifold (the fan just stays there while its pulley spins away as per normal), and have had no overheating issues.
just take it off asap! sooner or later the viscous clutch will lock up and shatter the fan, not a good look next to a spinning engine. its only one reverse threaded 32mm nut to undo to take it off
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