So I've been working on my project 318 dart and am now moving onto cooling system. I've never worked on older cars and wanted to see if what I have is complete or not. I see the water pump and the fan attaches to a pulley on it but I don't have a fan clutch. The car is a 1970 but the motor from what I was told by previous owner is a 74 318. Should I have a fan clutch or was that not a factory thing back then? By the way a fan shroud is on my list of things to get. Thanks!
Cooling system questions
- Thread starter 70dart318
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You should be good with that factory flex fan. Probably won't need a shroud.
Is your dart a '70 as indicated in your tag line?
Yup it's a 70. Did lil research, didn't know about flex fans till now. So I'm good with this set up for now? Flex fans seem to have iffy reviews though lol might just keep it till I have more money to throw at it. I'm not gonna be getting very high in the rpm range anytime soon anyway. Just trying to get it to drive down the street lol
I was facing the same situation and fan/clutch questions in my car, but I have less room between the water pump hub and the radiator than you have so I had to go another direction.
Just as info - this is my opinion, and we all know what those are like because everyone has one. I would not run a flex fan. They are noisy, inefficient, and have been known to come unglued sending blades slicing through whatever is in the way. YMMV. A clutch fan has the advantage of working when you need it, and idling when you don't need it. This translates into less power-robbing from your output HP.
I did a lot of research and came to the conclusion a clutch fan is the way to go. I was told the shortest total distance is for a clutch and fan from a 74 Duster 360. It won't fit my early A, but it is supposed to fit the next generations of A bodies such as yours. I did not try this set-up as it's clearly too deep to fit my car, but the info was from a highly reputable source. It might be worth a shot in your Dart.
Just as info - this is my opinion, and we all know what those are like because everyone has one. I would not run a flex fan. They are noisy, inefficient, and have been known to come unglued sending blades slicing through whatever is in the way. YMMV. A clutch fan has the advantage of working when you need it, and idling when you don't need it. This translates into less power-robbing from your output HP.
I did a lot of research and came to the conclusion a clutch fan is the way to go. I was told the shortest total distance is for a clutch and fan from a 74 Duster 360. It won't fit my early A, but it is supposed to fit the next generations of A bodies such as yours. I did not try this set-up as it's clearly too deep to fit my car, but the info was from a highly reputable source. It might be worth a shot in your Dart.
Factory flex fans are pretty good and much stronger than cheap, scary, and sharp aftermarket flex fans. Clutches fail also.
If this set up doesn't cool as it is, I would have an old fashion radiator shop clean and rod your radiator.
BillGrissom
Well-Known Member
Should be fine since a factory design. But whether adequate depends on where you live in NV. I think factory cars shipped differently for AZ. A recent post linked a magazine article where they tested various fans in small block Mopar engines. As I recall, the factory clutch-fan w/ shroud was the best combination of cooling w/ minimal power loss. Some after-market flex fans were power hogs and also didn't move as much air, though they made a lot of noise. You appear to have enough room for a clutch-fan (~3", I recall). If not, some people use ones for other cars like Jaguar which need less axial space. All small-blocks were the same length, but the later aluminum water pump on your 74 engine adds 1" over the cast-iron w.p. It was around 1970 when they switched, so your car may not allow a clutch-fan. I couldn't fit even a thin M-B one in my 65 small-block after I changed to the aluminum w.p. Measure carefully so the fan doesn't eat the radiator.
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