Radiator Size ????
As has been said, get the biggest TWO CORE radiator you can get in there. Two big cores will out cool 3 or 4 smaller cores all day long.
And then, as pointed out above you need to get the water pump speed correct. Never and by never I mean never ever slow the water pump down to less that crank speed (under driven). You may save 2 HP but you’ll lose 12-15 HP because you can’t control engine temperature on hot days. And that makes the same engine much more sensitive to detonation.
So, a big two core radiator with a high flow pump and thermostat and turning the water pump at least crank speed (overdriving the pump is even better unless you are shifting at 8500 plus and then you need to worry about blowing the fan apart…unless you have an electric fan) and you can drive through downtown hell on the hottest summer day in slow traffic and your engine temperature will be under control.
Yeah, not all that is true.
Two cores with big tubes will not
always out cool 3 cores with smaller tubes. You actually have to do the math, figure out the surface areas, flow rates, number of fins, all of that. There are 3 core radiators out there that will out cool large tube 2 cores. The factory ran 3 core radiators too!!!
There are two major gimmicks in radiators at the moment. One is more cores, the other is big tubes. The companies that just add cores will sell you a 4 core radiator and say it's the best, despite the fact that the air going through the radiator is slowing down and heating up, making the additional cores less efficient as they go. The companies that add giant tubes will say they're best, despite the fact that they may actually be losing surface area, or that the large tube will not cool as efficiently all the way across that larger cross section. Both styles can become less efficient as things get extreme.
Bottom line is, "bigger tubes!" is as much a gimmick as "more cores!" if you're not actually checking the numbers and doing the math. A well set up 3 core can out cool a poorly set up large tube 2 core, and a well set up large tube 2 core can out cool a poorly set up 3 core. I would stay away from 4 cores just because of the overall thickness of the radiator, which can also be an issue with the really large tube 2 core radiators. It does have to fit in the car.
Do a search on FABO for "overheating"
Then come back and tell me what they have in common.
Easy, poorly set up cooling systems for both electric and mechanical systems. Want the Reader's Digest version?
-Electric fans that don't move enough air (expensive does not equal good)
-Mismatched pulley's under driving the water pump
-Wrong water pump for the pulley ratio (factory ratio .95:1 pumps had 8 vanes, factory 1.3:1 ratio pumps had 6)
-Poorly controlled electric fans (manual switches and temp probes are not great)
-No shroud (mechanical or electric), fan not covering enough surface area or pulling across the entire radiator
And you can even throw in mechanical fans that are too small or don't have the right number/shape of blades (they're designed to work at a certain RPM), electric fan systems with wiring that's too small or with alternators that can't provide enough juice to meet the specs, plugged tubes, radiator hoses sucking closed, thermostats not opening correctly (or removed altogether), internal engine passage issues, etc, etc.
But people that slapped together a poorly thought out electric fan SYSTEM will say electric fans suck. And people that spent a brick on a fancy radiator will say cheap radiators can't work either.
I actually ordered the Contour fans, a BeCool set, a Dorman set, and a Jeg's set. I tried them all for fitment to the rad. The best was the Jeg's #555-52115 which are actually Maradyne fans. It really covers a lot of the rad surface area and has the little rubber flaps where it doesn't to allow airflow. So that's what I used and sent the others back. I like the Contour since it's a production car unit but with my 22" rad, it was too wide and would have had fans covering the rad support and not as much on the rad. I can say if you have the hood open and the fans on, there's a lot of air/heat blowing at you!
FWIW - I use the Milodon hi-volume #16250 water pump.
I'm sure there are many ways to make a system that works. This is just what I did.
Exactly!
The OE Ford Contour fans work best on a 26" radiator. I love mine, my car will run at whatever temperature I program the fans for as long as the thermostat matches that temp. And I just run a standard thermostat, the 8 vane pump correct for my pulley ratio, and a Champion 26" 3 core radiator. There are a lot of ways to set up a good system, and even more ways to set up a bad one.