Ok, so?

What year is your disco? What are you running for radiator, water pump, inline, t stat?

big difference between 30” and 33” tires on the engine load

per Extinct - your math doesn’t work for me

so everyone telling me they run sub-200 when he is the expert and already told me that 200 is the best I should expect when it’s 90’degrees out seems to contradict the guy who created the in-line to start

if the Disco 4.6 can’t break 100 over air temp, then at stock it would have only run at 190 right now

so add 10 for the load from
mods and 200 is the bottom

why I am between 200-210 is the question and if I can do anything about it

 

This is the big tell, slowing down does the job which is a giant reduced load. Remember wind resistance goes up with the square of speed. Again we could compare MAF reading (this would be the true engineering measurement) but my guess is you are using a lot of fuel/btu's at that speed. Everyone chiming in doesn't have the same level of load you do. My relatively stock trucks run right at 200 degrees at 70mph when the air temp is at 98-100 degrees with the AC on (Columbia SC to Athens GA area last summer - extreme humidity) with the safari grill and no winch. A lifted truck on 33's, winch, roof rack is A LOT more wind load.

I don't think any of those parts other than the larger radiator are going to help. You are likely getting plenty of flow through the radiator from the water pump (what is rpm with 33's @ 70?). You can try Safari grill (I run it on all of mine, improves about 5 degrees) and water wetter (supposed to improve radiator efficiency - relatively low cost to try).

LS is not going to change the cooling equation which is horsepower to push the load and cooling capacity to cool the horsepower. Still going to need a bigger radiator. You could buy a custom made radiator in the DFW area for 1/10th the cost of the LS swap.

 

The LS comment was more about getting rid of all of my maintenance issues - not just temp - but yes my plan included redoing the entire cooling system with the LS since the cooling capacity needs is considerably different. Not quite there yet but getting pretty close lately since I am in the cycle where I fix one thing and something else happens because of it...

Is a Safari grill the same concept as the Saudi grill? Basically a piece of mesh in place of the current grill or is a Safari a different concept? If it is the same, did you just cut out the middle of the existing grill or fab something different or can you buy one?

Do you think water wetter is better than the Purple Ice? I was looking at that last night also and seems like opinions vary so curious what you have found.

Two other things:

1. at what temp should I really be worried? again there are opinions everywhere but is 220 truly point of concern for damage? or higher? is running 210-215 for extended periods an issue?
2. I asked this before but don't see answer - which side of the reusable gasket does the tstat need to be one? I have it installed on the "grill side" of the gasket and just want to make sure since the instructions don't cover it and you have pics of it on both sides on your site.

 

IMO, I think that a major issue here is the vehicle profile and speed. I rarely drive my 04 over 65mph and I don't have a rack, etc creating even more resistance than it already has. An off road set up is for going slowly off road IMO not cruising at 80 mph. I guess I'd be curious about how the cooling system works in a slow moving off road application.

 

Just returned from a Northern Arkansas trip with the family. We had the truck loaded pretty good with four people, dog and gear. The truck is a 04 with a 2" lift, 235/85-16 mud tires (31.75") which are heavy. Extinct inline, Nissens radiator new in the last 2 years and all new coolant hoses. Weather was humid and in the 80's. On the highway at 65-75 the temps stayed pretty even in the 183-194 range depending on the elevation. This was the outbound leg and the AC was turned off for most of the trip down from KC. Now, if you have ever been to Northern Arkansas you know it is not flat. Once we got into the Buffalo river area and started the climbs, temps started to climb. For most it went up to 200-204 before cresting, then dropped quickly back down to the 180's or lower. Climbing up to Mt. Sherman it did get to 210, held there until the summit and then dropped on the decent. On these climbs you are mostly going slow due to the tight hairpins and they are steep. For me thats about 30-35mph max. So you are trading less airflow for speed load I guess. On the return trip with AC on and temps in the high 80's, it stuck right at 200-204 at 65-75mph. I consider 70mph the sweet spot for my truck. For the most part I was impressed with how temps behaved. My truck has 185k, runs well but I know the engine is tired. I leaked or purged zero fluids or used any oil. Scan gauge said 14.7 mpg

So my post trip questions are -
What happens on a real mountain pass that lasts for many miles and longer times? Say, I-70 over Vail pass or up to the Eisenhower tunnel? With a well functioning cooling system, which I think mine is, do the temps stop climbing at some point? What speeds can be held? I have driven all over Colorado for years, just not in my D2. I felt like in Arkansas I ran out of mountain before the temps got scary, but if the climbs kept going who knows.

On radiators -
Does anyone have experience with the aluminum options you see on ebay? There are others CHR, etc but the GPI link is below. Cost is in the stock range. They advertise more cooling and capacity but who really knows? My amateur thermodynamic thought is increased capacity would help but surface area is what it is and maybe set with the space available.
https://www.ebay.com/itm/28406126216...oaAsrsEALw_wcB

 

• 04 Disco
• 4.6 Liter
• Nissens rad about 2 years old
• In line thermostat 180
• Stock Water pump of unknown age
• The throttle body heater was completely bypassed - lower intake directly back to the expansion tank
• The Electric AUX fan working correctly
• Run 89 Oct shell
• 10/40 Royal purple HPS
• No oil cooler
• Transmission serviced 5 years ago
• Copper Discovery St Max 245/75/16 47 lbs each
• Steel rear bumper but it is about the same weight as old resin one

Picture for reference

 

Another data point for you @FtWDisco2 since I ran in warmer weather yesterday coming back from a climbing trip fully loaded with climbing gear and 2 people. Keep in mind, I suspect my rad is partly blocked because I see 188 around town as well whereas before I would regularly see 177-182 with a heavy duty clutch.

Ambient temps 50F to 80-85F. Cruising speed 70-80mph over rolling hills on the highway. A/C set to 70F.

Setup: 2004 D2 with 4.6 161k miles, OE water pump (30k miles), Nissens radiator (10k miles), 180F inline stat, Dorman fan with Hayden Severe duty clutch, "saudi" grill mod
Relevant mods: 33.1" KM3s, ARB bumper with winch, dual spotlights ahead of grills, RTT, sliders, 4.12 gearing

Cruising temps from 188-195 depending on ambient temps. On hotter climbs on the highway, I saw as high as 206F on the scanguage. A/C was on most of the time even at low speed climbs on the roads up to where the crag is located. I hovered in the 200F range when climbing at low speeds in backroads but this was mainly due to using the severe duty clutch. Running a HD clutch in 70-75F I would see around 208-209F from experience 2 weekend ago in this same area.

 

so is the severe duty clutch helping at highway speeds?

how did you do your Saudi grill mod? Do you have a pic by any chance?

I may take my grill out grill out for a test drive and test the idea that removing that portion that is blocking airflow will help

 

Severe clutch makes no difference at highway speeds. I don't have a photo of the grill but I cut out the center slat on the facelift grill and glue/ziptied a mesh to the inside area so its flush with the remaining slats. I don't think it made a huge difference tbh but I want to redo it so there's more airflow. Just haven't had time to work on that project because I have two other project cars besides the D2 haha

 

so what did you change from a few weeks ago that got you the temp reduction driving the same area? The in-line?