Heavy Duty Radiator
- Thread starter Bigrichrod
- Start date
1of40
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It seems there are always 3 ways to skin a Rover so I'm more or less sharing that a simple/cheap toggle switch on a efan that I flip on before the temps start to typically climb has done the trick. I'll add that I'm running a 5-6 year old $500 Proline rad from RN, a HD clutch fan, good t-stat, and fresh coolant. I also monitor my temps through the ECU with an OBD2 app.
This is why I stopped messing around with all of the guess work and just spend a lot to get a setup that I know works. Honestly, I’ve probably spent 20 hours trying to isolate issues on a single defender, and have done that several times on other defenders. There is no one common issue.
I even switched to a RRC 11 blade fan and fan clutch on my D90 which was inadequate. Electric fans fixed that one
MountainD
Technical Excellence Contributor
Jimmy, when you are out next, let’s hook up my trailer and go up I70 to the Eisenhower tunnel and see how the E-fans do on the way to camping! I’d love to see how they work for others! I should have crap dialed in by then for myself if need be. either way, I’ve got a couple sites to show you and the fam that I think you’ll like.
If I still had my D90 I would! I don’t think my 300 Tdi 110 could hit 50mph on flat ground towing a trailer 😂. My 110 has an Allisport radiator and mechanical fan which seems to work fine. I’ve never had issues with diesel fan clutches or radiators.
DPdotCOM
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Reviving this thread: I'm convinced the primary issue with my cooling is just the lack of shroud/cowling/funneling of air from the radiator. The standard revotec setup is this, which has TONS of open space where the fans are not pulling air:
Ron Davis and Alisport both offer shrouds to help funnel the air through only the fans:
Has anyone seen shrouds like this for sale without buying an entire radiator to go with it? I saw this, but I've never heard of this company and it seems kind of random/sketchy.
If I was more caught up on projects, I'd just do all the measurements and have it made via Send Cut Send, but I just don't have the bandwidth right now.
Ron Davis and Alisport both offer shrouds to help funnel the air through only the fans:
Has anyone seen shrouds like this for sale without buying an entire radiator to go with it? I saw this, but I've never heard of this company and it seems kind of random/sketchy.
If I was more caught up on projects, I'd just do all the measurements and have it made via Send Cut Send, but I just don't have the bandwidth right now.
Shrouds make a huge difference at low speeds. For optimal performance a fan should be a minimum of 3/4 inch away from the fins, the further the better for even flow. I made my own shroud with 1 inch spacing for my R2.8 conversion.
Note, above like 35 mph the fans can't keep up with the airflow and shroud/fans become a restriction. A lot of performance radiators that cant add extra surface area will include cutouts around the fan with silicone flaps that suck closed a low speed due to the fans, but at high speed blow open.
If you have the revotec and you are overheating at idle (with fans on), a shroud would help. If it is overheating at speed above like 35 or 40, you need more surface area (bigger rad). Access to a press brake would be able to make a great shroud in like 10 minutes.
Note, above like 35 mph the fans can't keep up with the airflow and shroud/fans become a restriction. A lot of performance radiators that cant add extra surface area will include cutouts around the fan with silicone flaps that suck closed a low speed due to the fans, but at high speed blow open.
If you have the revotec and you are overheating at idle (with fans on), a shroud would help. If it is overheating at speed above like 35 or 40, you need more surface area (bigger rad). Access to a press brake would be able to make a great shroud in like 10 minutes.
I built up my 300tdi with the following:
2.8 L injector nozzles
Rebuilt FIP
Billet turbo
Standard width, extra depth intercooler
Electric vacuum pump
I used the RN HD radiator, and it's 100% up to the task. It's a tdi, so it barely runs at operating temp anyway. There's no way anyone on this forum puts their truck through what I do.
2.8 L injector nozzles
Rebuilt FIP
Billet turbo
Standard width, extra depth intercooler
Electric vacuum pump
I used the RN HD radiator, and it's 100% up to the task. It's a tdi, so it barely runs at operating temp anyway. There's no way anyone on this forum puts their truck through what I do.
Mattarm
Well-known member
Using the Maradyne MK22KT mated to the 3.5L V8 Defender radiator on my LC9 swapped 110 which is meeting my needs. To the point raised earlier, I am only at 900ft of elevation and temps creep when climbing at elevation.
Ash
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DPdotCOM
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I have a rebuilt 4.2 V8. And I'm only struggling to cool it in two scenarios:
I currently have the stock RN V8 rad replacement with the Revotec fan kit: https://www.roversnorth.com/parts/pll885_radiator_defender_1983_1991
I went electric years ago bc my viscous clutch died. But I'm not opposed to going back to it if it's the right move. But I never had a shroud, it was just the fan. I still have the water pump on there with the threaded fitting that could accept it.
- driving over sand, where it's hot as hell at sand level even on moderately warm days, you're pushing through the sand AND you're only going 10-15 MPH, and
- sometimes I've had the temp creep up a bit when sitting in traffic on very hot days (aka trying to cross the Bourne Bridge in July).
I currently have the stock RN V8 rad replacement with the Revotec fan kit: https://www.roversnorth.com/parts/pll885_radiator_defender_1983_1991
I went electric years ago bc my viscous clutch died. But I'm not opposed to going back to it if it's the right move. But I never had a shroud, it was just the fan. I still have the water pump on there with the threaded fitting that could accept it.
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erover82
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The Revotec fans are fine but the lack of a shroud makes them really inefficient. With the symptoms you describe, I think you're on the right path. An Allisport radiator probably wouldn't do you any good and would probably be a downgrade in reliability.
Sounds like a shroud should fix it. At low speed your rad is effectively only the size of the fans, and fans being right against the rad is not the most efficient for the blades. A shroud with proper spacing may give you like 60% better cooling. R2.8's are known to run hot and I can watch my temps drop instantly when the fans kick on.
I highly, highly doubt it. Everyone is welcome to post up photos and videos. It's not just the couple-times-a-year, but I wheel more frequently than most anyone here as well.
In the last week, I've snapped a rear axle shaft, wheeled twice for 8+ hours both times. Drove it home in 4-High. I see a lot of trucks get built to high heaven, and used less than a quarter of the time mine does.
Again... bold claims are easy to shoot down with ammo. Have at it.
Ash
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Shroud should make a big difference given what you described. Our radiators are a pretty odd size so the likelihood of finding something drop-in is quite low. It's a simple fab project though, surely someone can build you one for cheap if you don't have the time to design something yourself.
I hope you stick around the Defender world long enough to be able to reflect on the hilarity of bragging about breaking an axle shaft. The 'poser shot' photo of your stock 110 on a green trail is all the ammo I need to shoot down the claim that you're wheeling harder than anyone here. It's cool that you're actually using it because that does seem anomalous these days, and you should keep that up, but I assure you that if you're hoping to claim 'most hardcore' title, you've got a long way to go my dude.
I hope you stick around the Defender world long enough to be able to reflect on the hilarity of bragging about breaking an axle shaft. The 'poser shot' photo of your stock 110 on a green trail is all the ammo I need to shoot down the claim that you're wheeling harder than anyone here. It's cool that you're actually using it because that does seem anomalous these days, and you should keep that up, but I assure you that if you're hoping to claim 'most hardcore' title, you've got a long way to go my dude.
That local construction site trail looks pretty intense.
DPdotCOM
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you've inspired me folks, I'm gonna just design the shroud. In fact, the first draft is in Send Cut Send already, but I'm going to cut it out of cardboard first to mock it up before spending $100 on aluminum:
Is there any science around the proper spacing away from the rad for maximum efficiency? My current totally random choice was 1" separation.
Does the thing need to be relatively air tight, or just reasonably good? Debating if the thing should wrap totally under the rad or just meet the face of it with a rubber edge piece
Is there any science around the proper spacing away from the rad for maximum efficiency? My current totally random choice was 1" separation.
Does the thing need to be relatively air tight, or just reasonably good? Debating if the thing should wrap totally under the rad or just meet the face of it with a rubber edge piece
Ash
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I think reasonably air tight is good enough. The Ron Davis radiators I use just have a simple foam strip around the perimeter to help seal, but there are air gaps present. Ideally you want all of the air entering the core to exit through the fans, but some bleed is probably inconsequential. Can't offer much on the theory of spacing, but on these the face of the fan hub is roughly 1.75" from the core.