Electric Waterpump

[italiansedanman]

IS the US fan meant to be more specific to warmer climates?

[Tifosi]

That or for more stop-n-go driving.

For either/or you'd need a bit more airflow :shrug:

Consider also that as the US speed limits were generally lower than pretty much anywhere else, so you couldn't go screaming down the highway and rural routes at Autobahn speeds to keep forced air moving through the rad. (55mph was the limit from mid-70's til the past 8-10 years or so......)

[cameron]

hey all sorry for bringing up an old topic but i have a davies craig eletric water pump in my 1987 33 boxer 1.5 i have removed the stock mechanical pump, the pump is wired into the ingnition so when you turn the key it comes on i have also hooked up an over ride switch so it can be turned off. but the biggest problem i had and i think you guys are having is the heat issue when you turn it off. my way around that was to install a TURBO TIMER i purchased as a kit(kc-5379 around $30au) from jaycr electronics. the kit allows you to set a time from 1second- 15mins i found this is a cheaper way around it so i didnt pay $250for the original davies craig timer. i also installed a turning knob similar to a light dimer or volume knob on a radio this was because the pump was making everthing run cooler than it should around 70'c( i was told to cold and ill have engine problems later on) so you can adjust the temperature you want it to run i found this good driving in the city allot i could turn it up so it ran cooler but as soon as i got out on the highway/freeway id turn it down so it ran at about 110'c and not at 70'c

im not an electronical minded person but the kit was easy enough to follow the instuctions and the guys at jay car helped me identify some of the diodes and other things.

the pump cost me $300 and the kit cost $30 and a $10 soldering iron and $5 for wirring and other little peices. the davies craig gear would of cost $600 for just the pump and the temp switch.

if you have any questions or cant understand some of the stuff ive said let me know and ill try help out

cameron

[Tifosi]

Quote:

Originally Posted by cameron i also installed a turning knob similar to a light dimer or volume knob on a radio this was because the pump was making everthing run cooler than it should around 70'c( i was told to cold and ill have engine problems later on) so you can adjust the temperature you want

[cameron]

the guys in the shop figured that out for me would it be the same ohms as the pump

[slyalfa]

unless the thing is a monster it would need some PWM amp in it.
Around 1980 I made a linear one for the heater fan and the power transistor needed a huge heatsink and the fan air the heatsink was at lest 4 inches long 2 inches thick and 3 inches wide.
So a pot would need something like that much cooling too if used alone. but if you use a PWM circuit it could be done in a tiny box without any cooling about the size of a small reley.
and it is just about as easy to have it temp controled as is to use a pot.

[FMG_V6_btb]

Here I present you a OEM electric water pump used in many BMW:

A source of inefficiency in some engines is the conventional water pump. Water pumps need to supply enough flow to cool the engine at full throttle. But the majority of driving situations is at part throttle, when the engine is producing less heat. Without a means to vary pump speed independently of the engine speed, the conventional water pumps are too big for the task. A pump that is flowing more coolant than needed for the engine is consuming more horsepower and more fuel.

The solution is the electrically driven water (coolant) pump, controlled by the engine electronics (EMS) by means of maps.

Conventional water pumps also circulate coolant when the engine is still cold. Electric water pump is switched off while the engine is warming up, this strategy allows the engine to reach its operating temperature quicker, reducing emissions. Also when the engine is stopped, electric water pump keeps the flow to avoid engine overheating.

As you can see, there are many benefits when installing a electric water pump.

Regards.

Paco.

[OzMidnight]

Reasonable write-up/review on a pump from another site.

redlinegti.com :: View topic - Davies Craig Electric Water Pump Setup - Full Review/Update

[cameron]

i dont know on increase in power but think of it as a standard pump runs off youre crank shaft, take away that extra weight it will give you better fuel comsumption and it will accelerate quicker.

just my .02c

[Sniady]

Paco beat me to the punch.

BMW is using these water pumps on all there NG engine (new generation engines). The DME (digital motor electronics) controls the water pump and so does the heater.

The pump only runs when needed, it can also bleed the cooling system when replacing a part of the cooling system.

An electric water pump would be nice for alfas, but would be to complicated to design a variable controllable one.

[slyalfa]

hmm a OEM pump sounds very good a lot of the race pumps have very short lifes. but a OEM pump should last a long time. the control of a pump should be very easy. say have a min flow so the coolent will flow past the temp sender then have a steep ramp up after the set point say 85°C almost the same setup for the cooling fan. if a controler was made might as well control a electric fan too.

I wonder how much the BMW pump will cost...

[FMG_V6_btb]

The BMW EWP uses a brushless electric motor (in fact is an AC motor), which improve the pump durability.

About electronic control, things are a little more complicated here, because control is made via CAN protocol. So you need to replicate the original BMW CAN protocol, or made your own electronics

Paco.

[iachella]

The piece that I don't quite understand is what you do with your existing pump, exactly? If you gut it, how about the hole that the drive goes through? Do you have to weld that up? And how about the alternator belt? You can't just route that alone, can you? Won't it pull the crank out of ballance? Maybe you need an idler pulley at the old water pump? If you take out the impeller and leave the pulley, it's still subject to bearing failure, right? That doesn't seem very good.

I can understand the benfits of this electrical pump, but I just can't picture what to do with the old equipment. Can someone who's done it be more specific as to what they did?

Thanks,

[FMG_V6_btb]

The best solution is to replace the actual pump for a plate with the coolant inlet, but that could be difficult to manufacture, so I think the best compromise is (if a new belt can be used) to take out the impeler, shaft and seals from the original pump, and install a stopper or plug instead.

Also you will need to take out the thermostat from it housing in order to better control the engine temperature.

Any problem with crank balance, pump pulley has not relation with that. Why don't post you some pictures from the front end of your engine? just to see the belt layout and pump inlet.

Paco.