Topless, I don't have a C4, but I did just remove the stock fan and fan clutch in favor of a single 16" electric fan that I got used for $45.00. So far it is working great. I let the car run at idle in my garage ( with door open for 20 minutes. I use a 180 thermostat and the fan is set to turn on at 185 and shut off at 170. The car heated up to around 185, fan kicked on and car cooled back down to around 170 at idle. Can't beat that. The only think I have not tested is in the dead of summer or with the a/c on. My a/c does not work and probably won't for many years. Many folks go with dual electric fans;however, for a mild 350 I think a high power single 16" fan works great and allows for better air flow at highway speed. Based on my dyno, I picked up 20 hp and 12ft-lbs of torque. I also think my gas mileage went up.
mine has a brass 3 row, have you run your car under hot conditions, our car will be operated in temperatures above 100 degrees with the air conditioner on, and thats why I was wondering if the single fan cars experience problems, my mustang fan set-up didn't work out the way I wanted, so now I need to figure out a electric fan set up, seem like each move I make on the car, I usually end up back where I started LOL, however the serpentine belt drive is working wonderfully
Size alone is not the important factor. There are so many things that go into a successful cooling fan conversion.
In fact, I had a V8 in my S-10 using the stock 4.3 V6 radiator, and I mounted a pair of 12" pusher fans on the grille side and was able to achieve perfect cooling capabilities in the dead of summer with the a/c blasting.
The trick is, the fan has to be very close to the radiator. At the same time, there has to be enough flow through space all around so that at highway speed you can get natural air to push through. If the single or dual fans cover too much radiator space, you might overheat at 65 mph.
However, the tighter and better fitting a shroud is around the fan the better. So, you will notice many factory cars have little doors or flaps built into the shroud. These open towards the motor. When the cooling fan is running and frontal pressure is low the little flap doors stay closed. When the pressure in front of the radiator at high way speeds increases beyond what the fan can recirculate the doors pop open allowing air to free flow in around and out of the radiator fins.
So, if you can put together a single fan (16" is good) and a good tight shroud that hugs the fan and covers the back side of the radiator. Then put two large flaps/doors and or four smaller ones to vent off the high speed air, you should be able to make that radiator you have now work like a champ.
I plan on doing what you see noted above on the 69 big block. I feel one fan done right is the best way to go. I will build my shroud out of fiberglass.
69MyWay has the right info. My fan sits about 1/8" from the radiator which is a three row also. The day I tested it at idle it was about 70 outside. I live in the south were it will be in the upper 90's to low 100's during the summer, but I won't be able to fully test my setup until the heat returns. At some point in the future I plan to get the a/c working. At that point, I may add a small electric fan in front of the radiator. There is about 2-1/2" of space between the radiator and the a/c. I'm confident that I can get a small secondary fan in there. If not, I can offset my 16" fan to one side and add a small secondary fan.
I can't speak to the particulars but my 85 which runs in south Florida year round Avg 90+ in the summer months never overheated with a/c on constantly. I did run at about 210/215 in traffic and about 200 on the turnpike. Since I installed the 160 with stage ll chip I never get above 190 with a/c in traffic. The stock fan did a good job. I have read the pros and cons of operating temperatures. Some say the car should be at the 200+ mark. All I know is she runs much better at the cooler temperatures.