Ron Davis Radiator Update

zonker

SILVER Star
Joined
Mar 3, 2015
Messages
336
Location
Lonely Nevada
Website
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!
 
Last edited:

zonker

SILVER Star
Joined
Mar 3, 2015
Messages
336
Location
Lonely Nevada
Website
www.willenosphotography.com
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!
 

zonker

SILVER Star
Joined
Mar 3, 2015
Messages
336
Location
Lonely Nevada
Website
www.willenosphotography.com
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!!
 
Joined
Apr 12, 2019
Messages
42
Location
The Dalles, Oregon
Visit site
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.
 
Last edited:

Onur

11101-17020
Moderator
GOLD Star
Joined
Aug 28, 2004
Messages
29,871
Location
Tabasco, NY
Visit site
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.
 

zonker

SILVER Star
Joined
Mar 3, 2015
Messages
336
Location
Lonely Nevada
Website
www.willenosphotography.com
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.
 

Users who are viewing this thread

Top Bottom