Now that my 67 standard is on the road, I’ve realized I have a cooling problem. I’ve got the 20" 3-row radiator with a 6-blade fan and no shroud. I’m currently flushing the system to get all the rusty crud out. I’m currently on the second flush. I’ll probably flush it two more times. However, I don’t think there’s any way this radiator and fan combination is going to support air-conditioning in Houston heat and stop-and-go traffic.
After watching Don’s video, I plan to switch from the 20" to 24" radiator, but I’ll probably grab this 2-core aluminum one with 1" cores (https://www.johnsmustang.com/1967-1968-mustang-radiator-aluminum-8-cyl-small-block-24-rh-lower-hose-high-performance) from my local guy.
I was wondering if anyone had tried the electric dual fan kit (https://secure.cougarpartscatalog.com/50-5067.html)from WCCC. I like the fact that the shroud is made for the 24" radiator and that it has all the thermostat controls included. I was just hoping to get some reviews before I order.
Your current fan will work fine with a shroud and a 3 core 24" rad. Same design as a 427 GTE or 428 CJ and it kept them cool! Save your money I say.
Don, first off, I want you to know that I highly respect your opinion, and I’ve watched all your videos and read all your advice posts.
However, when I did my 66 Mustang about 15 years ago, I started with a 3-row copper with shroud and the six blade fan. Then I moved to a four row copper with the shroud and the six blade fan, and that worked until I got the engine rebuilt and bored .030. Then it would never hold temp when sitting in stop and go. The local guys suggested switching to the aluminum 2-row, and it helped, but I still vividly remembering sitting in bumper to bumper traffic with a panting labrador in the backseat attempting to evacuate from Hurricane Rita and having the car overheat and die even with the air-conditioner off because it was about 95 degrees with an insane amount of humidity and the air moving along the road was heated up even more by car exhaust.
I learned my lesson on that car that doing things right the first time is much cheaper than trying to do them cheaply and having to re-buy multiple parts.
I’m really hesitant to spend $100 on a fan shroud when I’m almost positive I’m going to have to go with an electric fan to get enough cooling in gridlock situations.
We have a car in right now with the electric fan and it is not performing well (cannot use AC on hot days) so we are going back to the clutch fan. Keep in mind no 24" rad is available for the 66 stang, 24" wide makes a big difference.
Ok, I’ll give it a shot.
I know you prefer the original style radiators over aluminum, but it’s only a $30 price difference between the 3-row copper and the 2-row aluminum here, and while the aluminum takes slightly different brackets from Scott Drake, they’re the same price.
Is there a reason not to go aluminum?
They do not dissipate heat as well as Brass / Copper and do not hold up as well.
The advantage of electrics is that they effectively cool the engine when stuck in traffic. OEM’s wouldn’t use them if they weren’t effective
I have twin 12" fans on my 68 - that is a +30 roller cam engine and they work effectively with a shroud or mounted directly to the radiator. I’m running 24" radiator and a wider condenser with a/c and live in the sub-tropics where temps get sit around 90F for three months of the year.
My fans pull around 3000cfm
Biggest cooling issue I have is related to the a/c condenser. I replaced the Ford one with a wider condenser, thinking it would aid cooling with R134. It doesn’t and it blocks airflow to the radiator at cruising speeds. No problems at all under 50mph but on a longer run at 60mph on 90+F day, the temperature will gradually creep up. I have same temp issue with the same condenser on the 69 - and it currently has a fixed blade fan and shroud while I was diagnosing problem
69 will get a 14" fan and 12" fan combination with a shroud that doesn’t cover as much of the radiator face and slow air speed at cruising speeds
I also run one of the fans when the compressor is on and have a block mounted temp sensor, although I might consider putting a bung and sensor in the bottom radiator tank to get a more accurate reading
Eliminator has these sitting on the shelf. Ford Australia setup for their 302 and 347 windsors
I agree with Don. 24" OEM radiator with OEM fan and clutch will keep you car cool, also make sure you have the shroud installed. I live in So Cal and can sit in traffic with the AC on when its 90 degrees out. All day long. Im running a stock j-code 302
I am most likely going electric fans when the time comes. The fixed blade non clutch setup has to go! Electric are just as efficient as a clutch with the right setup and as a bonus they remove that parasitic drag on your motor.
Electric is actually far less efficient in real terms. What they may do is deliver more air when the engine is at, or close to, idle. This may be reason enough to use them if you are frequently sitting parked in stop and go traffic or if the car may end up idling for long periods in hot weather.
A mechanical fan using a fan clutch that slips at high RPM or when the engine is cool, connected to a very aggressive fan with big blades is about as efficient as you can get. Electrics are powered by an alternator that consumes more horsepower than it produces in electrical current. And the motors consume more power in electrical current then they produce in mechanical energy to spin the fan. This is all simple physics. What electrics do better than mechanical systems is to deliver high CFM air at idle. Once you are moving down the street, both systems are essentially just along for the ride.
Houston is nothing but stop and go traffic, but I’m going to spend the $99 on a shroud and try the mechanical fan first.
I’ve flushed the old 20" radiator four times now, each time making sure I hose out every section of the cooling system. I went from the temp climbing any time the car was accelerating to being able to stay cool on the freeway with no problem. I put in both a new sending unit and gauge before I started anything else.
Here’s before the flush.
Here’s after four flushes.
I put a new 180 thermostat in, and 180 is just a little left of the T in the word Temp. When I’m driving on the freeway and on roads that are 40 mph plus, I have no issues. The needle doesn’t even touch the T.
My temp starts rising when I get back to my neighborhood, and I have the long slow trip through my suburbs at 20 mph with lots of stop signs. I’ll go from just left of the T to between the E and the M. My hypothesis is when I’m creeping through the neighborhood, often just idling, not even really gassing the car, neither the fan is working fast enough nor is the car moving fast enough to move the needed amount of air to get effective heat transfer in the radiator.
I saw no temp change between flushes three and four, so I think this is about as clean as this system is going to get.
The car came with this 7-blade flex fan.
Now, I fully plan to convert to the 24" radiator, which I know will increase the overall cooling capacity, but this slow speed problem is what had me leaning toward an electric fan in the first place. Logic says that a 3000cfm electric fan is going to move a lot more air through the radiator than a mechanical fan when your engine is only running at 500-1000 rpm and you’re moving less than 20 mph.
Unfortunately, once the temp gets up between the E and the M, which I’m guessing is around 210, it never cools back down no matter how long I let it idle in park. It just ever so slowly continues to creep up.
So that’s my situation and the reason I was leaning toward the electric fan.
Hopefully the increased cooling capacity of the 24" radiator will be enough to compensate for fan speed.
Look in the top of the radiator at the end of the tubes. They are soldered to the floor of the top tank. The copper of the fins and the brassof the tank are very resistant to corrosion, but the solder is not. Corrosion always favors the least noble material. The solder will bloom when it corrodes. When the radiator is rodded out they are actually filling out some of that solder bloom that restricts the flow through the radiator. It is like having a restriction in an artery…
Also how is the condition of the outside of the radiator? No bent fins or packed with dirt or debris?
My J code rarely passes 1/4 of the temp gauge, and i don’t remember ever seeing it at 1/2. Slightly below 1/2 when in very hot weather, in crawling circulation. It just stays there. it has done plenty of stop & go traffic in Gatineau in the summer, and i often get carried away on long trips. It then stays even a tad below 1/4. Everything is original, and no shroud.