Aftermarket Radiator & Electric Fans

[matthew21lutz]

So I've been going through some old threads on here about radiator replacements. I need a good radiator, preferably aluminum and 3 core. I need to replace my stock one, it leaks a little bit, doesn't have a trans cooler and it's flat out heavy.

So I know some people are going to say, just get a trans cooler, I have one, but I don't like how the line are run. I got a stock th350 from the junkyard, works great, got the lines as well. So the lines are there but, from the end of the lines I have rubber hose going to the trans cooler and i just don't like it.

I need suggestions on where to buy. So if you're running an aftermarket radiator with dual electric fans, where'd you get it? How much should I pay? What about kits that include "everything" to change over to aluminum with electric fans?

Any help will be appreciated, I thank you guys for all the help!

[bbbc10]

I would run stock big block radiator and stock ls1 Camaro fans

[tucsonjwt]

I got a "stock" aluminum/plastic radiator from Auto Zone and I added a pusher fan from the pick and pull out of a Geo Metro (I had little room in front of the radiator because my truck has a factory oil cooler in that area, taking up about half of the available space.) I was a copper/brass radiator advocate in the past but I could not see paying $400-$500 for one like that now. Autozone had 20% off over $100 purchase so I paid about $120 delivered to my house.

I have a 83 C20 454 camper special and that Autozone radiator (Spectra brand, I think) works as well as the old copper/brass one. I got about $37 for the old copper/brass radiator at the scrap yard so my net cost was less than $100.

In my experience,a new properly sized radiator will keep your engine cool even in the 117 degree HotZona desert. So far, that aluminum/plastic radiator is working fine and I think I will not have the leaks I had with the copper/brass radiator. The radiator I got was only 2 rows but it seems fairly thick.

I installed the pusher fan earlier to improve the 134A conversion A/C on my old axial compressor and it helped a lot. I think it also helps keep the engine cool.

I think a lot of guys spend big money on dual electric fans and all aluminum radiators when it is not necessary. If your truck has a high horsepower modified engine than it may make sense, but I don't see why a stock engine would need that much cooling. It is possible to have an truck engine too cool (although truck drivers are always "too cool"

[notallthere]

When I replaced mine I went with the heavy duty radiator from Spectra CU730 I think. As for the cooling I have dual fans from a Windstar. Thus far I have not had an issue with either as the radiator is 8 or 9 years old and the electric fans have been in for 4 years now.

[1970pelle]

I'm using a Champion all aluminum 3 row radiator 19 X 28-1/4 core size. And for cooling a Flex A Lite, dual electric fans. That come with its own module that allows them to run at two speeds. They are an easy install, and work great.

I run my trans cooler lines in to the radiator first then a Hayden Trans cooler mount out in front of everything behind the grille. My trans temp stays at 180 to 190 degree's.

Ken

[SparkyRnD]

We also make radiators here in the USA using domestically sourced materials by hand to fit your truck (and we can put the inlet / outlet wherever you need at no additional charge). They are all tig welded, no epoxy or glue either. Plus, we are a site sponsor. Let me know if you are interested.

[gmachinz]

As stated, not everybody needs an extreme radiator and yes cost can be a factor. In extremely hot climates w/AC and even moreso with a built motor, a radiator upgrade is a MUST. Does this mean aluminum? It can....aluminum radiates heat more efficiently BUT-there is also the question of proper airflow-radiator material and volume mean nothing if you can't pull heat out. Going down the highway is never the problem-it's sitting in traffic on a 110 degree day with the AC on full blast. IMO a high output fan assembly is at least equal if not more important than the radiator itself.

Now, when choosing to go aftermarket (or more accurately...NOT STOCK) there are a lot of options. Spal, DeRale, Flexalite ect always get mentioned because they are easy to find. But there are issues besides the cost like being too loud (inferior blade pitch/design), lack of mounting hardware (requiring custom work), and all aftermarket fans use a pancake style motor for no other reason than its cheap to manufacture and they just can't pull big CFM unless you get into massive fixed and straight bladed assemblies which do pull some CFM but require a lot of amps to do so.

And never mind the generic aluminum shrouds they all seem to like...why? Cheap to design and build-ever wonder why Detroit uses high temp thermoplastic shrouds? I'd guess because they don't want hot aluminum shrouds building/holding in heat-plastic is cheap granted but the molds to make them aren't. The biggest fan assembly and radiator I can think of for our squares is a 6.2 Diesel radiator combined with a set of 2010 F150 dual 14" fans-this fan combo barely fits on the 6.2 radiators (yeah....they are massive!) and moves a reported 6000 CFM on high speed-no aftermarket fan assembly even comes close! I've built a few of them and at $430-440 for the fan assembly and built in 3-speed resistor control harness rated @ 100A it isn't cheap to buy but nor is it offshore cheap quality either! That's the extreme side-a stock HD clutch and mechanical fan being the low side of it. You just need to decide which direction you lean more too. Can you go overboard on cooling? I would say no-you just need proper control over the system.

I've seen too many people go skimpy just to try things out....get mad when it doesn't work like they thought and give up on it all together. Electric fans aren't scary and I would say the benefits outweigh the cons.

[tucsonjwt]

It doesn't get much more extreme in terms of heat than the southwest AZ desert and engines don't get much bigger than a 454, but the stock setup has worked fine for the past 14 years for me. I have had maximum capacity loads in it many times in the heat of summer.

My neighbor is continually having trouble with leaks in his all aluminum Champion radiator/electric fan set up. My preference is to spend as little money as possible and if it doesn't work I can use the Autozone lifetime replacement warranty and start over. I have about 8 gallons of $2 per gallon Peak antifreeze in the shed.

[hatzie]

The Lincoln MK VIII fan pulls 2700 CFM on HI and they are cheap. You will need to incorporate them into some kind of shroud to get decent cooling. I have rubber flaps over slots, like the VW radiator shrouds, to allow full airflow when driving at highway speeds.
The $300 SPAL dual 11" fans are only slightly higher.

Both fans draw 30-35A and starting inrush is somewhere between 50A & 80A so you need to size your wiring, circuit protection, and control contactor(s) accordingly.
See this writeup... http://www.corvetteforum.com/forums/...pal-duals.html

My MK VIII fan on my 2000 6.5L GMC never comes on when I'm moving. It will cool the engine down RIGHT NOW on LO. I've never had it come on full bore. The AC compressor bypasses the LO Coolant Sensor and it cools just fine at humid nasty sticky Cincinnati 105°F ambient outdoor temps.

If you'd rather not put parts made by the big blue oval on your GM... Another option may be the LT1 dual fan setup. There are some claims of 8500CFM with both fans on. Those same sources place the MK VIII fan at 5000 CFM full blast and I know that's baloney. I would bet the LT1 duals are somewhere of the order of 2500-3000 CFM but I have no real tests to back that up.

[SCOTI]

Revisiting this one....

I'm still trying to get the a/c in my dually going. We think we have the leak-down solved but another issue has come to light. The pressures are getting so high it's kicking the compressor off.

They charged it w/a nice fan blowing across the condenser (entire system is knew except the Evap). Everything looked good. On the high side but nothing outrageous. Once I started cruising around it was fine @ low speeds. Get into the throttle (like the on-ramp to the highway) & off the comp goes.

So it seems my fresh BBC radiator & fan combo isn't cutting it (fresh OE replacement 4-row brass radiator, reverse flow Stuart water pump, HD Murray fan clutch, slightly larger diameter Derale serpentine fan). The truck runs below 200°F but it is HOT under that hood....

I like the Ford F150 approach because despite the fact it's from F@#d, it's OE based which 9 out of 10 times is better vs aftermarket. Not really interested in doing the wrecking yard parts approach either. I'm a do it once, do it right type.

Any other easy swaps where parts you guys have used were available @ the dealership?

[hatzie]

Originally Posted by SCOTI

Revisiting this one....

I'm still trying to get the a/c in my dually going. We think we have the leak-down solved but another issue has come to light. The pressures are getting so high it's kicking the compressor off.

They charged it w/a nice fan blowing across the condenser (entire system is knew except the Evap). Everything looked good. On the high side but nothing outrageous. Once I started cruising around it was fine @ low speeds. Get into the throttle (like the on-ramp to the highway) & off the comp goes.

So it seems my fresh BBC radiator & fan combo isn't cutting it (fresh OE replacement 4-row brass radiator, reverse flow Stuart water pump, HD Murray fan clutch, slightly larger diameter Derale serpentine fan). The truck runs below 200°F but it is HOT under that hood....

I like the Ford F150 approach because despite the fact it's from F@#d, it's OE based which 9 out of 10 times is better vs aftermarket. Not really interested in doing the wrecking yard parts approach either. I'm a do it once, do it right type.

Any other easy swaps where parts you guys have used were available @ the dealership?

It likely has too much refrigerant. It's very easy to do when you move from R12 to R134a or R152a refrigerants.
If they slammed in refrigerant by weight as a percentage of the original R12 charge then they put way way way too much in the system.
You need just enough refrigerant to make the evaporator cold and a dribble on top of that so the evaporator runs right around 35°F or just above to keep from freezing the evaporator into a block of ice. The only way to do this is slowly dynamically charging the system when ambient temp is right around 85 degrees.

You could use the 1990's Subaru approach. Put a thermal compressor cycling switch on the evaporator and run the system slightly low on refrigerant. The thermal switch will cycle the compressor to keep the evaporator from turning to a block of ice. System pressures should be lower but the thermal switch becomes a very very important part.

I'm making the rash assumption you have a stock 7 blade fan and clutch with a shroud and side flaps to force airflow through the condenser & radiator stack.

[gmachinz]

Well pics are worth a thousand words so here ya go! I don't know of a more powerful fan assembly IF that is your problem. When it comes to cooling, so much attention goes to the radiator and IMO not enough on being able to pull massive CFMs @ low speed-and this is where electric fans beat mechanical fans all day long.

[SCOTI]

Originally Posted by hatzie

It likely has too much refrigerant. It's very easy to do when you move from R12 to R134a or R152a refrigerants.
If they slammed in refrigerant by weight as a percentage of the original R12 charge then they put way way way too much in the system.
You need just enough refrigerant to make the evaporator cold and a dribble on top of that so the evaporator runs right around 35°F or just above to keep from freezing the evaporator into a block of ice. The only way to do this is slowly dynamically charging the system when ambient temp is right around 85 degrees.

You could use the 1990's Subaru approach. Put a thermal compressor cycling switch on the evaporator and run the system slightly low on refrigerant. The thermal switch will cycle the compressor to keep the evaporator from turning to a block of ice. System pressures should be lower but the thermal switch becomes a very very important part.

I'm making the rash assumption you have a stock 7 blade fan and clutch with a shroud and side flaps to force airflow through the condenser & radiator stack.

First.... Thanks for the quick info. You're correct on your assumption. However, the OE fan/set-up was standard rotation but I swapped to a serp set-up & needed the rev rotation parts. I measured the shroud & noticed the OE fan was almost 2" smaller in diameter so I got the largest OD that would fit within the opening. I also swapped to the HD fan clutch while updating everything.

New parts used w/the OE BBC shroud were:
Stuart water pump (for a serp app BBC)
Derale fan (19" I believe.... maybe 20")
Murray HD BBC fan clutch
Murray condenser
Murray accumulator
Murray compressor
Orifice valve

Only other item I'm currently working on is the AUX fan is not running. I checked the lead running to it after work tonight & found there's no power coming from it. I wired the fan up hot & it works. I'm going to have to see where that wiring goes. Not sure if it's disconnected upstream or if that AUX fan runs off a different fused power source that's compromised.

The additional airflow ddefinitely made a diff when charging the system (they put a medium sized swamp-cooler in front of the truck on this go-around & it was a different group helping me this time vs the others.

[gmachinz]

Here's a closeup of the relays-my setup uses (2) 50A switching relays and (2) 100A load relays and these are controlled by my 3-speed conversion harness design for extremely high output fan assemblies-so this pretty much rules out aftermarket electric fans as nothing can touch the durability of an OEM setup such as this one from Motorcraft. From my research on various Ford forums, this fan assembly is moving airflow @ the 6000 CFM range on high speed.

[SCOTI]

Nice set-up. I've gotten one of your older Mark VIII set-ups w/the PWM controller for a previous build. I like/understand the reliability of the OE stuff (cop cars, ambulances, & similar sitting & idling for extended periods w/o over heating concerns is nice).

Is that set-up as effective w/my thicker OE style brass radiator?

[gmachinz]

I would have to say this setup is much more extreme as far as airflow-moreso than any other fan setup I've used or built. However keep in mind too that nothing is free-in order to pull huge amounts of air on high for example, it draws 40A to do it-this fan setup alone requires you to run at least a 140A alternator. I believe the Ford pickups have a 160A alternator stock.

[hatzie]

Originally Posted by gmachinz

Here's a closeup of the relays-my setup uses (2) 50A switching relays and (2) 100A load relays and these are controlled by my 3-speed conversion harness design for extremely high output fan assemblies-so this pretty much rules out aftermarket electric fans as nothing can touch the durability of an OEM setup such as this one from Motorcraft. From my research on various Ford forums, this fan assembly is moving airflow @ the 6000 CFM range on high speed.

Relays to switch the contactor coils are needlessly superfluous. You can switch DC contactors directly. The coil side of the contactor will usually draw less than 1 amp and certainly less than 2 amps. You can use much cheaper 20awg wire on the coil side and save the heavier and more expensive 10 - 14awg wire for the short runs on the switched side.
You can get a 300-1,000v or better spike from a relay or contactor coil. Needless to say this is bad for any electronics or switches in the coil supply circuit. An extra relay will still spike and ring just like the contactor. The spike is an inductive pulse from the electromagnetic field in contactor/relay coil collapsing when the voltage is removed (similar to collapsing the 12v primary field in an ignition coil generates 60,000v in the secondary). The solution is to place a diode across the coil contacts biased with the Cathode toward the positive connection. Any diode will do the trick. I use 1N4xxx power diodes. This will reduce the inductive spike voltage to a reasonable level... usually 5v or less.

Fan CFM is like HP and torque numbers from add on components. Marketing goons use a bunch of sleazy tricks to make their product look better when it isn't.

I bet this is free running CFM. Real world as in pulling through a restriction like a radiator will give wildly different numbers depending on fan blade shape electric motor torque at operating RPM etc.
http://www.oldairproducts.com/catalog/electricfans.php

I've seen the MK VIII fans listed as 4,000 CFM and even 6,000 CFM on HI when real world numbers are actually between 2,300 & 2,700 CFM on HI mounted on a radiator with a shroud.

[gmachinz]

The relays I use in this instance are specific since the fans speed changes based on dropping resistance. I know it isn't scientific but if I walk past the front of my truck grill with fans on high speed with a big loose shirt on, the fans will draw my shirt to the grill from about 4" inches away. This is with a stock type 4-core brass radiator and AC condenser. Airflow on the engine side is about like sticking your hand out the window going down the highway....lol

[gmachinz]

And these 100A relays have built in suppression protection btw-I'm sure TYCO knows what they're doing.

[hatzie]

You can buy relays and contactors with and without snubber diodes or resistors in parallel with the coil. The cheaper parts typically don't have them. I add them to the relay sockets used in the harness on some of our products at work so the end user can buy cheap SPDT ISO relays without causing spikes.

You can feel the air pulling my windbreaker when the MK VIII fan kicks in on my 2000 T400 C2500 even on low. Sources I trust rate it somewhere between 2,300 & 2,700 CFM at a static pressure .5" of mercury.

The rating you're looking for will actually be a graph of CFM vs static pressure in inches of mercury. As stated in the article a "regular" condenser and radiator stack will run between .4" to .7" of mercury.

[gmachinz]

I noticed a typo in my previous post-should have read dual 16" fans-not 14". At any rate, I can't find any hard data on these Mororcraft F150 fans-trying to locate the CFM rating but so far nothing. They differ from previous Motorcraft designs in that they have straight blades vs curved so they are fairly loud @ high speed.

[hatzie]

They're probably on par with the MK VIII fans or even a little more. Without the honest figures you don't know.
Not sure what the relatively common 90's B Body GM cars and LT1 F-Body dual electric fans ran in honest CFM either. It's worth finding so we can post a real honest list. They may be fairly close. OTOH some of them may be pretty anemic.

I know my finely tuned hand gauge tells me the LT1 B Body fans moved a lot of air... How much is "a lot" in corrected CFMs? I don't know.

[hatzie]

Originally Posted by SCOTI

First.... Thanks for the quick info. You're correct on your assumption. However, the OE fan/set-up was standard rotation but I swapped to a serp set-up & needed the rev rotation parts. I measured the shroud & noticed the OE fan was almost 2" smaller in diameter so I got the largest OD that would fit within the opening. I also swapped to the HD fan clutch while updating everything.

New parts used w/the OE BBC shroud were:
Stuart water pump (for a serp app BBC)
Derale fan (19" I believe.... maybe 20")
Murray HD BBC fan clutch
Murray condenser
Murray accumulator
Murray compressor
Orifice valve

Only other item I'm currently working on is the AUX fan is not running. I checked the lead running to it after work tonight & found there's no power coming from it. I wired the fan up hot & it works. I'm going to have to see where that wiring goes. Not sure if it's disconnected upstream or if that AUX fan runs off a different fused power source that's compromised.

The additional airflow definitely made a diff when charging the system (they put a medium sized swamp-cooler in front of the truck on this go-around & it was a different group helping me this time vs the others.

What are the blade lengths for the Derale compared to the stock unit? Some of the GMT400 fans have some pretty short blades.

[SCOTI]

Originally Posted by hatzie

What are the blade lengths for the Derale compared to the stock unit? Some of the GMT400 fans have some pretty short blades.

The Derale fan blades are at least 1" longer than the original fan.

[hatzie]

Originally Posted by SCOTI

Revisiting this one....

I'm still trying to get the a/c in my dually going. We think we have the leak-down solved but another issue has come to light. The pressures are getting so high it's kicking the compressor off.

They charged it w/a nice fan blowing across the condenser (entire system is knew except the Evap). Everything looked good. On the high side but nothing outrageous. Once I started cruising around it was fine @ low speeds. Get into the throttle (like the on-ramp to the highway) & off the comp goes.

So it seems my fresh BBC radiator & fan combo isn't cutting it (fresh OE replacement 4-row brass radiator, reverse flow Stuart water pump, HD Murray fan clutch, slightly larger diameter Derale serpentine fan). The truck runs below 200°F but it is HOT under that hood....

I like the Ford F150 approach because despite the fact it's from F@#d, it's OE based which 9 out of 10 times is better vs aftermarket. Not really interested in doing the wrecking yard parts approach either. I'm a do it once, do it right type.

Any other easy swaps where parts you guys have used were available @ the dealership?

Originally Posted by SCOTI

The Derale fan blades are at least 1" longer than the original fan.

With the larger than stock fan you are moving enough air through the stack at idle and sedate cruising but the compressor cuts out when you get in it. Over 30mph the fan is not moving more air than the road speed is pushing through the stack.

At WOT the ECM on a TBI engine should kill the AC compressor til you back off the go pedal. Not sure if all of them do. It gives you a temporary HP boost for passing etc. My 76 has a WOT compressor kill switch on the 6.5L diesel. I installed it on purpose.

If this is not a WOT kill switch... you are describing an overcharged AC system or a failed or incorrectly sized HPCO switch.