Electric Water Pumps (EWP)

3gress · Postby **3gress** » Fri May 20, 2016 7:56 pm

Its a -16an fitting.

I ran it like this for a while. I'd be in for a standard alt. mount cnc bracket madjak!

madjak · Postby **madjak** » Fri May 20, 2016 11:02 pm

First one is cutting now.

It will take a couple of days for this one to finish as I'm taking it pretty easy.

Rick

madjak · Postby **madjak** » Mon May 23, 2016 1:43 pm

Done...

The surface finish is nice and smooth. I mounted the end mill too far out of the collet initially and it was chattering anf damaged the side walls. I moved it further in and the cut cleaned up a lot. Still it came out nice and it only weighs 345 grams which is far lighter than my hand made one.

It all bolts up fine.

Ive fitted on the plastic flange for now but I've ordered an aluminum one from Davies Craig for final.

plohl · Postby **plohl** » Mon May 23, 2016 4:34 pm

Looks awesome man. Very cool work! :beer:

madjak · Postby **madjak** » Wed Jun 22, 2016 4:26 pm

I've completed a bench test of the EWP on a spare engine to get a gauge of how fast the coolant flows. One of my concerns running a reverse flow is bubbles trapped at the top of the head. I'm running the EWP off a 11.3V RC battery so it's not running at full pace, but would be close enough for a test.

Here is my test setup:

Front 12AN fitting comes off the front of the engine at 45 degrees so that it clears the timing belt. At this stage I'm running hose fittings to the radiator so that I don't have to modify the flanges on the radiator. One day I might switch them out to 16AN so that it looks a bit tidier.

Compact 12AN fitting at the rear of the head to clear the firewall.

I'm running the coolant in and out of a tub of water so that I can see if there are bubbles being expelled. As part of my build I also made a billet manifold that bolts directly to the Davies Craig pump that splits what is a 16AN ouput to 2 x 12AN lines which run to the front and read of the head.

The coolant flow that the pump puts out is easily sufficient to blow any air out the head and into the block. The water comes out of the pump in a strong solid flow through the 12AN lines and combining to push enough water out of the block to make a big mess on the floor of the workshop. After a few seconds of running the output is clear of bubbles and flowing cleanly. I'm pretty sure it's evacuating all the air out of the engine as multiple restarts of the pump show no additional air bubbles in the output. I end up running the pump for several minutes with no issues at all so I'm now confident to install the system on my race engine.

IanR · Postby **IanR** » Wed Jun 22, 2016 9:34 pm

Impressive work there, well done, Im sure your sowing many seeds with this great thread.

plohl · Postby **plohl** » Wed Jun 22, 2016 11:11 pm

That's awesome dude!

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gslender · Postby **gslender** » Thu Jun 23, 2016 3:13 pm

I doubt a mechanical pump on our engines zaps much more than 2 hp. Large V8s are seeing 10hp, but those pumps are seriously bigger. It would be fairly easy to test with an electric motor, of which if you can spin the water pump with your battery drill (which I can) then I'm fairly sure I'm only using up 500 watts or less!!

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Postby **NitroDann** » Thu Jun 23, 2016 3:59 pm

But can you spin it at 8000rpm with your drill against a partially open thermostat?

Dann

madjak · Postby **madjak** » Thu Jun 23, 2016 4:42 pm

I think there is also some power loss due to accelerating and decelerating the water mass. This might not be massive and will depend on how quickly the engine is climbing in revs. Held at a constant 6000rpm I think I'd agree with you and it won't consume massive amounts of power, put basically the water pump is accelerating and decelerating 2kg of coolant and then pushing that though the engine. If what I'm imagining is true then it should affect the rev rate unloaded as it would be equivalent to removing any spinning mass.

With the electric water pump, you can hear it loading up for a few seconds whilst the coolant gets up to speed, then the load on the pump eases off and the noise it makes reduces. I could actually measure the amperage it draws, and I think you'll see higher amps up on startup and less when running as speed.

So total power loss =
Less MoI from spinning the metal water pump
Less MoI from not accelerating and decelerating the water mass
Friction from bearings and belt
Resistance from pushing coolant past tight bends and thermostat

All of them might add up to a 2 or more HP at high revs... Who really knows without an engine dyno. If I had easy access to a dyno I'd do a before and after to get an actual benchmark, but to transport my car to the dyno, plus the cost whilst on the machine makes it too hard.

madjak · Postby **madjak** » Thu Jun 23, 2016 4:59 pm

I should add that I don't think the choice to do this mod is specifically to free up power. That's just a bonus. Personally I'm doing this primarily so that I can cool the car whilst it is sitting in the pits and run the head cooler.

gslender · Postby **gslender** » Mon Jun 27, 2016 4:08 pm

NitroDann wrote:But can you spin it at 8000rpm with your drill against a partially open thermostat?

Dann

Even if I had an electric drill, and even if it operated at the max watts for 240V (which is 2400watts) it would amount to 2.4kw and that's only 3.2hp.

Are you really thinking the mechanical pump is doing more work than an electric power drill - I'm pretty certain my pool pump is pumping more volume than the water pump in a car.

C'mon... let's not have that argument :roll:

madjak wrote:I should add that I don't think the choice to do this mod is specifically to free up power. That's just a bonus. Personally I'm doing this primarily so that I can cool the car whilst it is sitting in the pits and run the head cooler.

Now that sounds about right.

G

madjak · Postby **madjak** » Mon Jun 27, 2016 4:31 pm

There are several dyno comparisons online, mostly on V8 engines showing a good 10hp saving from removing the mechanical pump. This thread is a good example: http://fepower.net/simplemachinesforum/index.php?topic=959.0. In that thread the OP is mostly comparing power loss of a non-electric fan vs clutch and no fan, but he also dyno'd with an electric water pump instead of the mechnical. All up there was a 30hp saving between fan + mechanical water pump vs no fan + electric water pump. Of that 30HP approx 1/3rd is due to the EWP.

Personally I can't imagine 10HP going through a 4-rib fan belt, let alone from spinning a water pump, but if a Rotrex can sap 40HP and that is just a small impeller pushing against air then maybe 5HP from a spinning blade in water is accurate.

I almost feel like it's worth spending some $ on the dyno time to find out!

Dann, you might be able to answer this one. If the BP head is running 5 degrees cooler, how much extra timing / boost could you run with a turbo setup? Approx how much HP would you gain from a cooler head due to running reverse flow coolant. N/A I doubt it's a lot, probably none if you are running e85, but with 98 it might net you 2-3HP just from being able to run some extra timing.

3gress · Postby **3gress** » Fri Aug 05, 2016 5:17 pm

Bump for progress report :wink:

You will have to throw a pic up of the engine and plumbing once installed in car Madjak.

madjak · Postby **madjak** » Fri Aug 05, 2016 6:06 pm

Sorry no update yet. I've been away on holiday and its been damn cold in Perth. The install has been started but then I got distracted by rebuilding my dad's mini cooper motor with crazier cams that mine and playing around with porting a head. Plus my next event got cancelled so I have more time again before I need it done.

I'll report back as soon as its on.