O.K.,
So I do not leave well enough alone, lol. I love to mod and this truck is not my daily driver. This weekend I will be changing out my water pump to the new high flow brass type and putting in a new radiator. I found a couple of 12 inch fans, about 1400 cfm each, they came with a 180 degree thermostat. I have searched and read a few threads on the subject but no one has posted real world numbers that I can find.

I would like to know what the average running temps, highway, stops and idle temps are. If there is spikes in the temp depending on slow rpm usage and if there is any mpg benefit. I am not concerned with the mpg so much, just want to see if the electric fans instead of the fan clutch could show any benefit other than slight weigh savings and less stress on the water pump and engine drag. I would also like to know the water temp sensor thermostat range being used. I have put some thought into that as well and I know of adjustable thermostat that works very well so I can play with the on/off for the fans.

I am familiar with this kind of cooling and I have used it on street rod and Cobra replica builds before with great success, just not sure how it relates to the Discovery. If I can keep a 428FE cool under the hood of a Cobra I would think that it applies here as well, just need to get some input first. I will of course be posting my numbers in about one to two weeks.

Thanks,

Mike

 

The D2 stock stat (not an in-line) is start to open at 180F, full open at 204F. Had recent post from an owner with an Ultra Gauge seeing mid 180s thru 190s, had not touched 200 yet, 70F outside. The D2 logic is set to bring on AC condenser fan at 212 F to assist cooling. 180 Stat seems like a good idea. I suspect that it won't exactly track the coolant stat, but instead lag behind, coolant one will start to open first, more heat to radiator, electric fans come on, cycle repeats. Electric fans might not run at all at say 40 - 50 mph. Would run more in slow traffic. Keep in mind the coolant temp sensor is some distance from the coolant thermostat, there will be a time lag.

Also the air flow should always be from grille toward engine block. My PO didn't and with AC I would overheat but only at idle and slow, when both fans were "fighting" each other and net flow was zip. You would also not want to mount electric fan stat on lower part of radiator. If rows became clogged over time, they would be cooler than normal (not much hot water inside), less overall cooling, and stat would keep fans off, sort of a double whammy.

Please post pix of all the details.

 

Hey Savannah,
Very good points. I am going with a adjustable thermostat so I can play with the On/Off settings. I also will use my Ultra Gauge to track the temps. I will either use the temp sensor port on the new radiator or a probe type sensor, not sure yet. What do you feel the best place is to pull temp data from? I will be doing a lot of tests and I will post pics and data here on this thread. Any and all suggestions would be great.

Thanks,

Mike

 

I believe a 180 setting on the fans may be too cold, 32 degrees from what the ECU is looking for.
As for normal warm temp running, you will normally see in town temps around 204 to 206, idling at around 110 and high way at 195 to 198.
I am not sure how you are going to install an adjustable t/stat with out screwing with your hoses and by-passing the heater core but I believe you are going in the wrong direction.

 

Always worth a shot. I have plenty of time and the money is not an issue, got the D2 for little out of pocket. If things don't pan out I can always switch back to the clutch fan and use the electrics on another project. I do see around town temps now of 204 to 208 and its 55 degrees out. After I get my new water pump and radiator in I am assuming that will go down. I agree 180 running temp is to cold. Looking for a steady 194-204 around town, beach, off-road in 100 degree weather. Seeing I can adjust the on/off temps I am betting I can get close. The T-Sat is not getting changed or adjusted, the temp sensor (thermostat) for the fans is adjustable, sorry I did not explain that well.

Thanks,

Mike

 

Very interested to see how this is gonna work out. I also have been interested in running a similar setup. Couldn't really find any real information about it. My other cars have always had an electric fan. MJ, I think the balance we need to find is open and closed loop temperature and not overheat or undercooling. I live in jersey, if you wanna confer on your poa, let me know. Pm me.

 

Please keep us up-dated.

 

Well, if the RAVE says the temp of the mechanical stat is start to open at 185 and full open at 204. That is a 180 marked stat in the US market. In another place it says the "too warm" extra cooling from the condenser fan is ON at 212 and OFF at 202. So that could imply that 206 - 208 is OK, but it does not consider things back in normal range until under 204. And in another place it says if the ECT is failed the ECU will use a preset value of 185. So by what ever combination of settings, and the overall condition of your cooling system, staying close to 200 is good. Leaves you a little extra flow capacity for stat to open just a little more for long hills, trailers, etc. I would not think the ECU wants you to run at 212 for extended periods, or the extra cooling fan would not be stock programmed to come on. On the other hand, 50:50 coolant mix and 15 PSI cap raise the boiling point well above that. IMHO, the size of the temp swings is also an issue, keeping the operating temp range narrow keeps expansion changes minimal. As if the head gaskets needed an excuse.... The air temp coming out of the radiator will lag behind the coolant temp the ECT measures, let that be your guide from the OBDII port. The remote thermostat in a D2 adds fun to the mix, as ECT is some distance and elevation from the mechanical stat. In a D1 they are beside each other.

 

You got it. Here is my thinking on open and closed loop cooling. I have a car with a mid mounted aluminum engine, 2 radiators, electric fans come on at 195. This temp is maintainable in even in 100 degree weather at a stand still so logic says the same should be possible on a vehicle with even more airflow through the radiator. What is the closed loop temp range for a 4. 6 Disco II? That is important and the temps will need to be controlled to hold in that range. If I place the probe or temp sender at the right location and have an adjustable temp for the fans there might be a "sweet spot" that could be set.

As Savanna has relayed the temp range specs are a little fuzzy. We need to nail down operating temp and closed loop temps, I am sure they overlap. Seeing you are in Jersey, I may look you up after the install so we can put eyes on this and tweek it a bit. I am still a couple weeks away from completion as I want to have my new radiator and water pump in place so I am sure I am going to start from a factory functioning system before modding.

One other thought. We should set parameters to judge how things are going. I will use the Ultra Gauge for testing.

1. Warm up time
2. Optimal operating temp at idle with air conditioning on (and off)
3. Optimal operating temp driving at 55mph with air conditioning on (and off)
4. Off-road, beach, etc. slow crawl in high heat, say 85-100 outside temp with air conditioning on (and off)
5. Cold weather operation optimal operating temp under 40 degrees outside temp at 55mph

Also,
I guess we should do mpg recordings.


--Mike

 

What you want to avoid is this: