What cools better

I have battled cooling issues for long time. Recently, I saw a post about Champion radiators. People were praising them and how good they were. They said, " I can't get the car over 180* in 95* heat. I on the other hand have the exact opposite problem. So I have a poll before I switch to a Griffin radiator to give that a shot.

What do you use on the street? I'm not concerned about the track because that is a run then shutdown for cooling. I am looking for higher horsepower street driven cars. Mechanical fan and pump? Electric fans and electric pump, combo of both?

I use a AfCO universal radiator , just had brackets tigged on and adjusted lower hose outlet angle

Tex

In my 512 Duster, I have a Champion aluminum radiator, an aftermarket flex fan, and a shroud. Adding the shroud was worth at least 20 degrees, and the thing never gets over 180 even in traffic on a hot day. No other fans.

Shroud needed

512 ci, cold ac, driven in 105deg temps,runs 180 all day long, sitting in traffic or not, 2 row ECP rad, 18" 7 blade flexalite mechanical fan, 68 Charger so far runs 11.33 @ 121, just had the car weighed again, 4050 with me.

I have a 512 inch big block in my '65 Coronet. Mechanical fan, shroud and a 22 inch aluminum radiator. I have a 180 thermostat in there and it doesn't get much hotter than 180. My EFI system has a data logger so I can review how hot the coolant temp is after a drive. Hottest I've ever seen is 187 degrees. It gets the hottest if it is sitting in the sun at idle after a hard drive. If the car is moving then the temp stays down around 180. I think that having a correct shroud is super important. You also want some pump speed so make sure the pulley ratio is correct. For a street car you should be driving the water pump a little faster than the crankshaft. The lower the engine speed then the more pulley ratio you want. You need water flow thru the engine in order to remove the heat. The more water flow the better as long as the pump doesn't cavitate.

The '71 Charger with 500" stroker is still running the stock 26" radiator with the Mopar Performance viscous fan package. I also have a pusher fan in front of the radiator, but mostly use it in the pits to cool the radiator with the engine off. Although this works, it is on the edge, and it temps do creep up on long drives when it is 90+ degrees out.
My '69 Coronet 505" stroker had a Champion 26" 4-core radiator. Pretty good for the cost. With Mopar Performance viscous fan package, no problem cooling. With the Contour (Ford) dual cooling fans replacing mechanical fan, it still cooled good until I added A/C and the A/C condenser in front of the radiator. The extra heat load and reduced air flow from the A/C setup made that combination marginal in hot weather. I think mostly airflow related. I have switched to the Griffin Exact Fit radiator and Larger Spal 13" dual fans. I hope it cools better, but I have made other changes and have not driven the car with that setup yet.
I also had a GlenRay HD Radiator with the mechanical setup, and it worked great, but when switching to the electric fan setup I did not want to mess up that radiator so I set it aside and installed the Champion.
On the Champion radiators, I think in my setup the 3-core may have cooled as well or better than the 4-core because the 4-core is pretty thick and I think that partly reduced the air-flow through the radiator.

How does the inside of your radiator look when looking through the cap-opening (w/ coolant drained a bit below the toplevel)?

Are the channel-entries clean and open?

A citric acid treatment cured overheating in a 496ci setup with stock 3-row radiator for me.
The car still has a 1:1 crank:waterpump ratio, but it also has its stock 'narrow' steel shroud with a metal flex-fan partly inside.

Engine has 10.5:1 CR, XR274-solid roller, Edelbrock heads.

Before it had rust and scale-particles blocking the radiator channels and everything had a brownish color.

After the first full day-soak in citric acid, the radiator metal already looked like new, aside from a few deposites near the channel-openings.
After that I let it soak a few days more while occassionally tilting the radiator to agitate the acid inside.

I'm running thermocure through it right now. However, it didn't look too bad inside. It seems like the common theme above is mechanical. I have a double electric fan with a shroud covering 95% of the radiator.

Is there a source for a smaller water pump pulley?

I have a 7" single groove water pump pulley and a 5.75" crank pulley.

You are turning the pump way too slow. That isn't even 1:1 unless the crank pulley is the smaller one.

One thing to keep in mind when it comes to radiator selection a copper and brass radiator of the exact same size as a all aluminum or aluminum and plastic tank radiator the materials in them will determine which will cool better, brass and copper work better for cooling
Been there done that with a Griffin cooper and brass versus aluminum of the exact same size and construction other than cross flow versus vertical flow

Yes the crank pulley is smaller. My stock crank pulley was just a little over 6.5", didn't think it would matter a whole bunch.

I looked at a few different vendors and don't see any overdriven water pump pulleys.

That crank pulley was the only diameter Source had when I ordered a new one, my stock pulley had just a little tweak in it. I suppose I could look for a new crank pulley and throw this one in the spare parts box.

Decades ago we all bought the Morose aluminum underdrive pulleys to free up a few horsepower. Now that we have stroker kits and good heads we can easily make a lot more power and we are now digging through the junk pile where the spiders live to find the biggest crank pulley so that we can trade a few of those easy hp for some hard to find cooling. Funny how that works.

Bigblock cars that originally came with airconditioning had a smaller, dual groove waterpump pulley, but the alignment is off compared to the single groove pulleys.
Takes some spacing and realigning of crank pulley and alternator if you want to go that route.

My set up with the 540" HEMI is STOCK. The 26" radiator is even the correct part# for a 66'. Viscous fan, stock shroud and 180 degree thermostat. I also have the rubber "air dams" that the factory installed on the front and back of the hood. Driving in high 90's produces temps of 190-200 on the freeway at speed. As soon as I am on a back road, 45-55 mph, the temp comes down to 180-190. The factory knew what they were doing!

I changed out the 440 source water pump to a mancini 6 blade with the anti-cavitation disc; reduced temps 15-20 degrees. I also use the hi-flow 160F thermostat. i'm still not where I want to be but was very surprised by a pump change.

I voted electric, b/c that's what I use. Then realized you asked which cools better...that'd be mechanical. I'm just not willing to take the power loss.

I've also found that the stock blade-type waterpumps seem to flow/cool better than the newer style scroll type waterpumps.
Perhaps the scroll type impeller needs to be spun faster before it becomes more efficient.
I'm sure someone has done a study about that somewhere in the (recent) past.

My street car has a Becool aluminum radiator and a Spal dual fan set up with a shroud. fan is set of 200 and shits off at 175. Car never gets hot driving all over town. Engine makes 750ish HP on pump swill

Damn Al, what you sporting on the streets of Vegas with that much power........

Thats awesome!! That's what I need to hear. What kind of water pump? Thermostat / Restrictor? Water or coolant?

Come on Al, inquiring minds wanna know!

What cools best is kinda general... I can comment on what cools well for me. Application is a warm BB stroker driven on the street X country and and road track including 20-30 minutes of continuous hot laps with 130'ish on long straight and 100'ish on the short straight. The car has AC.

Radiator: Mancini 26" "muscle car" downflow AL radiator
shroud: matching "Muscle Car" shroud
Pump: older MP high volume with anti cavitation plate
Pulleys: Provide around 7% overdrive of fan and WP. Meaning the crank pulley is a little larger diameter than fan/WP pulley. I run a ~6 1/4" AL crank pulley and ~ 5 1/2" fan pulley from Bouchillon. The crank pulley is a bit smaller than stock BB 7 1/4" and keeps belt speeds around stock with my faster spinning warmed up engine.
Fan: Currently a Bouchillon 6 blade with Bouchillon sourced thermal clutch. The car was first built with a MP 5 blade fan/clutch package which was wiped out by a "gator" (along with some other stuff).
T Stat: Originally Mr Gasket high flow. Replaced with Milodon high flow. Both seemed to work the same. It runs a bit below stat temp rolling and a bit warmer at a stop, especially with AC on. Temp measured by EFI water temp probe.

On a roll, including hot lap sessions, the car never goes over the 180 degree stat temp. At a stop in hot weather and AC on it warms up a little but does not overheat. The Bouchillon 6 blade fan/clutch setup cools noticeably better at a stop vs the 5 blade MP setup.