Electric Water Pump question

[Dave Bilyk]

So far so good. I found a core plug to fit and got the electric pump running. A bit confused with the fan output from the controller, does it energise the fan relay or earth it? I measured a voltage of 1V when fan light is on. (Cold water after 2 minutes) Not sure if I can use this with my existing fan circuit which earth's to energise. Anyone know what voltage the Davies Craig Fan relay is?
Dave

 

[Brett James-McCall]

So far so good. I found a core plug to fit and got the electric pump running. A bit confused with the fan output from the controller, does it energise the fan relay or earth it? I measured a voltage of 1V when fan light is on. (Cold water after 2 minutes) Not sure if I can use this with my existing fan circuit which earth's to energise. Anyone know what voltage the Davies Craig Fan relay is?
Dave

I have the earlier controller. Does it matter? Should you not use the fan output to use it to switch the core fan relay anyway?

 

[Dave Bilyk]

Hi Brett, yes that's what I want to do, but trying to understand that the output from the Craig controller is compatible with my existing relays. There are two 12V core relays supplied from batt+ and earthed through the thermostat. I can change the cct so that thermostat is on +ve side and earth other side of coil, then connect in the Davies Craig Fan wire, but does it give 12V and will it handle two relays? :huh:

 

[Brett James-McCall]

Sorry, trying to visualise. You have 2 relays one for each fan?

Can you not just short the thermostat out to induce the controller into thinking it needs to switch on the fans and then test from there? You only need to make sure you hear the relays pick, or read the wire from the controller to determine whether it delivers voltage/current. If it's there running in parrallel to turn the relays on it doesn't need much to pick them?

Can you doodle a diagram?

 

[Dave Bilyk]

No problem Brett thanks for helping, I will post a diagram soon.
Yes separate relay for each fan. Batt+ to coils and both coils to earth thru the thermostat (existing). Davies Craig controller has internal solid state thermostat reading from a temperature sensor so I can't short it out to test, may have to run engine to test at weekend.

 

[Anthony]

Will post a picture of my electric water pump installation later, it's basically the same as Bill but with Silicon hose. I too have the EWP controller from Davies Craig but didn't use it for initial bleeding, just straight 12v to move as much water as possible.

Have you seen the new Carlos Fandango controller? Demon Tweeks have them.

Big digital display but more importantly it has a 2min over-run feature built-in. i was looking at using a timed relay in place of the standard one to get this feature but can only find them to run for either 10seconds or 10 minutes.

 

[Brett James-McCall]

Gibbo -The old ones had 2 min over run too. Mine is the 1st gen controller (pre integrated fan) and will over run. I plan on just siting in the car and using the dash fan switch to turn the fans on

Dave - I assume you are following the installations instructions (here: https://daviescraig.com.au/media/920/1431647745.8020-DigitalControllerPartNo.892703Apr14.pdf) or do you have a different controller?

 

[Dave Bilyk]

Brett Yes that's the same controller. Wiring diagrams on p5 is the same but with emphasis that the black 85 goes to Batt+. I wasn't sure whether to believe that, thought it was a typo, but with that confirmation it seems to say that the green wire goes thru internal stat to earth. Does that make sense?

 

[Dave Bilyk]

Thanks Brett, sorted. I managed to get an idle test after all.
When the fan light came on I checked the voltage of the green wire to earth, it was 1.1V . So I then trusted the cct diagram and connected the green wire to the existing tsat wire, runs both fan relays ok. I'll do a bit more digging to see if I can find the rating of the Davies Craig relay, don't want to overload the controller. I will post cct soon.☺ btw with fans on at tick over the cooling system holds its own about 80degC (15°C ambient)

 

[Dave Bilyk]

Brett, ok this is the complete wiring including the existing Fan relays and thermostat. Thanks for your help, it's appreciated. If any of you want a copy of the schematic program just Google ExpressSCH. There's also an ExpressPCB for designing circuit boards.
Dave

 

[Bill Musarra]

I have the Davies Craig controller, but I chose not to install it when I set my system up because I wanted a different way of electrically controlling the pump and the fans. The DC unit acts like an electrical thermostat. I like my engine to run a little cooler than most. Around 160-175. I have a large Griffin Radiator(3x26x19"), that with the 35gpm Moroso water pump and 205 AFR aluminum heads, allows me to run without a fan and get those temps while cruising in 90+ heat. I can tune the fuel efficiency with my FAST computer. I do like the run on feature and may still add the controller next year. Currently I use an off delay relay from Waytek to control 2, 5" fans at the front of the engine bay.
Off-Delay-Timer: 0-10-mins--adjustable: Solid State Relays | Timer Relays | Waytek, Inc
I had an issue with the paint in the tray surround blistering. Have added two shields and insulation to aid in blocking the heat from one of the exhaust tubes that stood proud of the others.

They have them with run times from a few seconds to an hour. I picked one that I could set at about 3 minutes. Didn't want to draw down the battery too far.

Bill

 

[Brett James-McCall]

Thanks Dave, I'll take a look at that.

I have the V1 controller and so my fans will still switch on via either the rad thermostat, trinary switch, or the manual switch I will have on the dash.

Getting close to see if I have wired mine up correctly...

 

[Dave Bilyk]

Bill, I see the height of the offending pipe.
Great work on your cooling system but your comment 'The DC unit acts like an electrical thermostat' implies that it only switches the pump on and off. On my controller it only does that for a quicker warmup, pulsing every 20secs , but once the temperature has come up a bit, it switches to what I think is a proportional mode running the pump at variable speed to control temperature. If the temperature increases 3degC above set point, say stationary in traffic, the fans come on. Set point can be 75,80,85 or 90deg.
Dave

 

[Bill Musarra]

Dave,
That pulsing is exactly what the thermostat does and then starts a more gradual opening as the temps in the incoming water starts to rise. I like the fact that it automatically turns the fans on when stationary. I use an electrical thermostat to do the same thing. I usually turn them on manually, but the thermostat is there if I get distracted. I am not running A/C so no need for the trinary. All of my wiring needs for the oil and trans coolers operate that way as well. I try to use the kiss principle whenever possible. The relays make the wiring simple and straight forward.

Bill

 

[Anthony]

Gibbo -The old ones had 2 min over run too. Mine is the 1st gen controller (pre integrated fan) and will over run. I plan on just siting in the car and using the dash fan switch to turn the fans on

This controller has overrun? Hope so, just dropped a load on Smiths Flight Gauges don't want to do buy another controller!!!!!

 

[Brett James-McCall]

No that's not the controller i am talking about the EWP80 would probably not be sufficient for the 302. I have the controller for the 110/120

 

[Anthony]

Hmm. I may not be a happy camper now. The items were bought separate on eBay and I am pretty sure the pump was advertised as the 110...

Anyone got details of identified marks on a 110?

 

[Dave Bilyk]

Ant, mine has a white sticky label. EWP115 P/NO 8125 QC PASSED.
On the body of the pump, it says DAVIES CRAIG PL PATENTS US 6425353 EU 11336624 AUS 756456
Dave

 

[Dave Bilyk]

Update; I took the car for a test run yesterday. Primary goal of preventing overheating in traffic/ when stationary is achieved. However, cooling is far too good when motorway cruising. Even with the controller only pulsing the pump, the temperature drops to around 50°C! I will put the wax thermostat back in and see if that gives control in parallel with the controller. Installation instructions say wax thermostat should come out.
I note that years ago, when I first installed the rear head bleeds, cruising temperature dropped to 70°C so another option would be to play with an orifice in that circuit, but I think that I just need to gain thermostatic control not reduce maximum cooling efficiency.
Dave

 

[Bob Putnam]

I put one of the original EWP115 pumps with the controller into a 450 bhp 331 cid car. It has functioned perfectly for the last 15 years, in all conditions. No thermostat necessary, and it runs at a constant 180F.