Ron Davis Radiator Update (1 Viewer)

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Joined
Mar 3, 2015
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Location
Lonely Nevada
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www.willenosphotography.com
As some of you might remember I purchased and installed a Ron Davis radiator in the fall of last year. Absolutely no complaints as it has provided a substantial coolant temperature drop. I love the radiator.. the quality.. the incredible welds.. the fit.. and the function. I still believe it is an "exquisite work of art". At 85º ambient.. I can drive for about 20 minutes before the thermostat opens. The A/C is not on tho. However I have not been a fanboy of the wiring harness for the SPAL fans that go along with that spec'd part of whole radiator package. In my humble opinion.. I think Ron Davis needs stick with what he is best at.. beautiful radiators.. shrouds and support hardware. Leave the electrics to someone else!

Initially I had to upgrade the mini fuses that are internal to the potentially waterproof GEP housing (relays, fuses, diode and wire connections). As a refresher to the thread that I posted about the failed mini fuses.. I created an external harness with 40amp ATC fuses to replace the suspect mini 40's which are unobtanium and don't last. I believed that the mini 40 amp fuses were incapable of handling the load from the fans.. especially at start up. After I eliminated them and replaced the circuit with 40amp ATC's.. the blown fuse problem went away and has stayed away for 6 months.

Now for the other part of the harness and hardware that I am not enthralled with. The SPAL Thermostatic Switch. Turned on at 185º and off at 165º. Well with type of temp range.. no matter how cold the ambient air.. the fans will always turn on and not shut off until you shut the ignition key off. Fan cooling this past winter was way more than needed. In fact I removed one of the 40amp fuses as I felt that oil temp stayed way too cool.. evidenced by my oil usage between 5k oil changes. Lots of overly high pressure oil due to temperature being pushed past sealing surfaces at normal RPM levels.

With a little bit of research I found that Painless Performance had a nice range of Thermostatic switches. Only problem they are spec'd to switch a ground. In the Ron Davis harness configuration.. the switch would be turning the relay positive coil wire off and on. Obviously a low amperage draw across the switch. Called Painless tech support and asked if the switch would work in that configuration. A solid definitely! Ordered up the #30113.. on at 205 / off at 190º. Perfect. The fitting for the SPAL is 3/8" NPT.. this switch is 12mm x 1.5. Located a 3/8" to 12mm adapter bushing and installed away. The bad news.. the switch only lasted about 3 weeks. Crap! Called Painless and they offered no help with a replacement.

I do believe I might have solved this Thermostatic switch conundrum.. finally! First off more research to hopefully find an even higher quality switch that could handle the low amperage 12vdc across "T-Switch". Absolutely no luck. So while taking a nice hot shower a couple of days later (great time to solve problems) I landed on what might be the solution.. short of going back to an OEM setup for fan duties. What if I got another Painless switch as they are of a high quality.. at least Painless has always had that type of reputation. Except this time not running 12vdc thru the switch.. but change it over to handle the other side of the relay coil.. aka the ground.

Had to strip down part of the harness and reconfigure it. Well.. how did it turn out? Works very well and now actually operates closer to spec'd temperatures. Before it worked good.. but not at temps that were more akin to the labeling. The great "lemonade" part of this whole procedure.. I had to drain the coolant in order to remove the SPAL switch. Was very easy with 4Runner style block drain that @NLXTACY at Wit's End sells. Bucket under the drain hose that runs down from the block drain. With a 10mm socket from the wheel well.. open the drain.. no muss.. no fuss. Put new coolant back in as I ran it all winter and spring and I wanted to make sure any contaminants flushed out. When I had to drain again to install the second switch.. sure was a SUPER easy drain / refill with the almost brand new coolant.

Would buy another Ron Davis radiator tomorrow.. just not the electric fan harness!
 
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Marco Lau.. the difference is.. I thought I was being really smart to go with the electric SPAL fans. Great fans.. but it would have worked perfectly with the modified blue hub.. OEM fan and shroud that I had to begin with. Trying to be one of the smart guys always gets me in trouble!! The SPAL's work great.. just had to sort them out.. but "YES".. I could have skipped all that!
 
One thing I have always been really good at.. pretending to be a Guinea Pig!! True story.. it was not a superior solution in regards to the harness. The GEP relay housing was spot on.. the solid state relays were of high quality. But the wiring execution and operational stability was definitely lacking. Nobody builds a finer radiator than Ron Davis.. IMO. However it is evident that electrical engineering is not his businesses strong point.

If anyone has this electrical fan setup here on MUD and is having any difficulties with correct operation.. definitely drop me a message. I can supply a new schematic which I drew up in response to the problems. Not saying I am an electrical guru. I do have some experience in the electrical arena and what I just finished up works very well. Should I have another problem to solve with this electrical control.. guess I will be picking up a whole new OEM fan setup.. sheesh!! The whole thing looked good on paper.. dang-it!!
 
I'd love to order one of these, but the website is down. They are still like 1k right? And can you still get one from some other means?

I should also add that the lack of other quality options really weighs in to the decision. It's a 1HDT which is very similar to a 3FE in the radiator department but most of the go-to's I see here are a not available, and OEM is not at all available anymore. That said, the CSF copper-brass I replaced it with is usually fine except in the big mountains which there seem to be a lot of around here. That and our ever increasingly hot summers (115* in Oregon today??) have me contemplating a next preventative step when I see the temp climbing up to 210* by the top of the hill.

edit: the website is working now from my home internet, maybe it was just not working on the net at my work.
 
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I'd love to order one of these, but the website is down. They are still like 1k right? And can you still get one from some other means?

I should also add that the lack of other quality options really weighs in to the decision. It's a 1HDT which is very similar to a 3FE in the radiator department but most of the go-to's I see here are a not available, and OEM is not at all available anymore. That said, the CSF copper-brass I replaced it with is usually fine except in the big mountains which there seem to be a lot of around here. That and our ever increasingly hot summers (115* in Oregon today??) have me contemplating a next preventative step when I see the temp climbing up to 210* by the top of the hill.

edit: the website is working now from my home internet, maybe it was just not working on the net at my work.

This is incorrect. OEM 1HD-T/1HZ/1HD-FT radiator for 80 series is still available from Toyota here in the US.
 
Nothing wrong with OEM radiators. CSF.. not so much. Had both OEM and CSF and the OEM is superior in my opinion. Since I am somewhat of a creature of habit.. I went with a CSF initially as radiators were always brass in my car building heyday. Unless of course you had unlimited dollars for an aluminum custom. Also you could easily re-core a brass one. Until I found out that no one does it anymore.

Then there is Ron Davis as well other high end radiator builders. Ron Davis is huge and very successful in the competition car arena.. from road racing to off-road. The reason I went with one of his.. I did not want to find myself staring at my UltraGauge. On super hot days going up and down mountains fully loaded it was hard for me to get my eyes of the gauge as it crept up. Like other MUD folks.. my 80 is pretty "porkie" with all of the extra steel and endless bits of other misc hardware.. recovery stuff and travel gear.

Not everyone needs a Ron Davis.. as the OEM radiator does an excellent job. However if you feel that you need the extra cooling and a minimum of $1100 works into your budget.. there is probably no finer radiator in my truly "humble" opinion.
 
Price on the RD Rad?
 
This is incorrect. OEM 1HD-T/1HZ/1HD-FT radiator for 80 series is still available from Toyota here in the US.
Not with the built in automatic transmission fluid cooler/warmer if I recall correctly.
 
Having recently finished overhauling my cooling system I also installed a RD radiator and with out a great deal of metrics I can attest that in recent wether in near the Bay the hottest my scan gauge has captured was 186’. Usually after I’ve let my truck idle while I run into the store for a few minutes. Grant it the warmest it’s been is 75’ here.

Also running the modified blue fan clutch and new OEM thermostat. Glad I pulled the trigger and no longer feel guilty lol
 
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Having recently finishing overhauling my cooling system I also installed a RD radiator and with a great deal of metrics I can attest that in recent wether in near the Bay the hottest my scan gauge has captured was 186’. Usually after I’ve let my truck idle while I run into the store for a few minutes. Grant it the warmest it’s been us been 75’ here.

Also running the modified blue fan clutch and new OEM thermostat. Glad I pulled the trigger and no longer feel guilty lol
Those are a lot of variables....low ambient temps, modified blue fan clutch....it would be interesting to see what you get when you drop down into the desert with 100 degree temps, running AC and climbing a grade. We want to know! :):)
 
@dsmud4u Congratulations on your trigger pulling. I have definitely found the radiator to be awesome. Plus it is an absolute work of art. Welds are definitely perfect and it fit the engine bay like it belongs there.

I had a neighbor who was a top tier welder who as a career put submarines together have a look at craftsmanship. He said whoever welded it up was an outstanding craftsman. Not quite submarine worthy.. but darn close!! He was a definite no bull***t guy. True story!!

Once again good job on a great choice! At least in my humble opinion :cool:
 
I use RD radiators in all the trucks I swap. I also use their twin Spal fan set up with shroud. Top shelf quality and service. I can not afford to send out a customer truck with anything less than the best available cooling system and the RD radiator is the heart of that system. Generally, fans are not needed at all once past 35-40 MPH. They just plain work and keep working.
 
LONG BUT WORTHWHILE READ, get yourself a beer and get comfortable.


I have been an advocate of electric fans pretty much all of my life, getting the combination of parts right is every important. I did run twin electric fans on a 500 BHP V12 without issue but let's get straight to the 80.

I fitted a two speed electric fan from a Lincoln 4.6 IIRC, I used two separate switches for the dual speeds and this worked fine, keep in mind it is a diesel but when being worked hard it makes no difference. This worked for a number of years and you will see everything I have done on my 80 here Builds - My LC 80 thread. - https://forum.ih8mud.com/threads/my-lc-80-thread.365673/page-33#post-14256806 One day when asked to help some friends get to a dog shelter that had been cut off by floods I used the 80, I have an overide to turn the fan off and drove through, without doubt the fan got filled with water but once through and back about half an hour later I let the fan dry out and switched turn the cut out off and got the engine hot and the fan worked fine. A few months later the fan was making a racket the bearings obviously gone, trying to get the proper two speed fan was a nightmare, the later ones were single speed and apart from that production had been moved to Mexico, and like the Optima battery quality fell when Johnson Controls moved production to the same place, I starting looking elsewhere. Eventually I found an electric fan with shroud on a Mercedes that looked promising, sure enough the fan blade itself is the same diameter as that on the 80 and the shroud took minimal trimming for it to fit the 80 radiator, which was not OE Toyota it was one I picked up from a store before driving the 80 from the UK over to Spain and certainly nothing special.

Now the Mercedes fan needs a fan controller and rather than go with trying how to figure out the Merc wiring I look across the pond and sure enough, a clever person had actually built a multi speed fan controller! I am sure the info is in my build thread, if not it might take some time to find as it was done years ago. IIRC it uses a stock Chevrolet temperature switch? The controller does everything most people want and is a quality item, it starts the fan off slowly when the temperature calls for it, it then ramps up the speed to cope with further rises in engine temperature, the controller was built to suit some American V8 which again is probably in my build thread. It has a take off that runs the fan at 50% of it's maximum to cover AC if called for. The Mercedes fan is sealed so no water worries there either, I did modify the controller for something which I cannot remember but it was something to do with a personal requirement, keep in mind we see 40* C temps here when out in the desert and I have NEVER had the fan come up to full speed except when I needed to check maximum amperage draw to confirm the size of circuit breaker I needed. I would point out during testing on the kitchen worktop (as you do) the fan was upside down and lifted itself from the worktop like a remote controlled drone, and with the fan pitched that gives you an idea of it's power.

I would like to dispel some of the myths that an electric fan cannot cope and have been voiced on this forum, the reasons are there if you look for them.

With a fan diameter along with a similar pitch to the stock 80 the electric version runs faster at idle this means it can pull more air through the radiator.
Then there is the AC factor again the fan coming on at 50% of it's maximum speed means your AC performs better, there is also the fact that when you get into a hot car but cold engine the viscous coupling is freewheeling because the engine is cold, so there is no real draw of air through the condenser or radiator, of course there will soon be some warm air being drawn from the AC condenser, but this is going to be drawn through a cold engine radiator, so some of that temperature will be lost before it reaches the viscous coupling so that continues to idle over, the electric fan is on within around five seconds.

There is also some weird math that someone came up with indicating that by method they came up with the fan drawing something 200 BHP? Now to the fan itself inside the housing is a range of capacitors, and if you understand how DC voltage works you will find that the fan builds it's speed from the these capacitors, recent brain surgery has left me without much of a memory so again referring you to my build thread, but needless someone needed to go back to school.

So is it all positives? The answer is no

First there is the complication of installing the wiring not much more than fitting spotlights with a relay but still has to be done. The trimming and fitting of the shroud which is a slow process to get it right, I cannot remember how I secured it but the car is outside, I am still on a driving ban given the recent brain surgery.

The temperature switch which is IIRC Chevrolet needs to be fitted, but I think I found one that changes resistance as temperature rises (note you can set the temperature you want the fan to come on via the controller), I put the switch in again another stateside offering a metal insert that goes into the top or bottom radiator hose, but it may well fit in a spare threaded hole in the cylinder head?

Then there is reliability, with so many components each one increases the possibility of the fan failing, other than the Lincoln fan failing which I blamed on the water dunking and again from the same place I go the switch tube the wiring whilst heavy enough for the job the quality of the terminal crimps was suspect so I made up my own, I would point out the Mercedes setup is simpler in wiring.

And as a lover of the rather isolated places you can get to here in Spain one of my spares is the old viscous unit, they are simple but old hat nowadays but would get you out of trouble. And so how has the Mercedes fan been? Nothing less than perfect, I had upgraded the alternator remembering the diesel does not need much amperage to keep it running (8 amps) but I upgraded from the stock 80 up to a 150 amp unit, that packed up after X amount of years so I put the old 80 amp unit in, I had no issues with amperage during the August of last year, but will fit another higher amperage unit when I am sure I will get my licence back.

I have never heard anything bad about the RD radiators on here so perhaps throw the Spal units and get yourself a Mercedes windmill?

Apologies in advance for typos as I lose concentration during the small fits I am having, and I have to keep going over it to correct them.

Regards

Dave
 
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Those are a lot of variables....low ambient temps, modified blue fan clutch....it would be interesting to see what you get when you drop down into the desert with 100 degree temps, running AC and climbing a grade. We want to know! :):)
Yes, looking forward to see the numbers going up the grapevine during the summer. I would see around 206’ on average with the A/C on with my foot mashed to keep up with traffic.

Nothing a Witsend’s turbo kit can’t resolve but that’s another topic of discussion.
 
Yes, looking forward to see the numbers going up the grapevine during the summer. I would see around 206’ on average with the A/C on with my foot mashed to keep up with traffic.

Nothing a Witsend’s turbo kit can’t resolve but that’s another topic of discussion.
My old RD radiator will never pass 200 climbing the grapevine, in the summer even with AC on full blast in the summer.
 

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