Direct Drive Or Clutch Fan On 440 Mag

[turbine68rt]

1968 440 mag, 22" rad, 727, no A/C. I purchased this car in 1987 and it had an oem clutch fan before I bought it with 77k miles. I recently talked a very knowledgeable Mopar guy who has been working on these cars for 60 years. He informed me that my car should have a direct drive fan. I said I thought all 440 mags had the clutch fan for performance reasons and I wouldn't know why a po would make the effort to locate an oem fan setup in the 70's when they could have just put on an aftermarket piece. Did this setup come with a clutch fan or direct drive? Anything is possible, just wondering what the typical setup was back then.

 

[R413]

Do you have a broadcast sheet? There is a spot for fan, spacer and clutch.

I’m generally seeing that 727 cars with 3.23 gears got a solid fan.

Previous owners did anything they wanted and our justification of why means very little today.

 

[turbine68rt]

Do you have a broadcast sheet? There is a spot for fan, spacer and clutch.

I’m generally seeing that 727 cars with 3.23 gears got a solid fan.

Previous owners did anything they wanted and our justification of why means very little today.

I looked everywhere possible for a sheet and couldn't find anything.

 

[Darter6]

Original owner guy had his 68 440 R/T Charger restored at a near by shop. His did not have a clutch fan.

 

[493 Mike]

Fan clutches are quieter in operation if that is a concern.
Mike

 

[famous bob]

Fan clutches are quieter in operation if that is a concern.
Mike

they are quieter, and dont have as much drag on the engine , on my 505 , the direct drive fan appears to run 7-8 degrees cooler than the clutch type. that being said , my ex 1968 426 street hemi came out w/ a clutch type fan.

 

[WileERobby]

If so, the p.o. installed the OEM fan setup because it works ! Are you concerned with originality or functionality ?

 

[68BabyBlue]

Baby Blue is virtually untouched original in the engine compartment, and I also have her broadcast sheet. Factory original direct drive fan with 22 inch radiator, 440 and 727 automatic. My third GTX, with A/C , was also direct drive, even though the A/C cars came standard with clutch fan. A one owner survivor car, with broadcast sheet, it was ordered with a spacer and fixed drive fan. The original owner lived in Richmond, VA, and wanted maximum cooling. The broadcast sheet will tell the story. In the absence of the sheet, it's your preference.

 

[turbine68rt]

If so, the p.o. installed the OEM fan setup because it works ! Are you concerned with originality or functionality ?

Originality

 

[ckessel]

Clutch type fans pull more air as they don't rotate as fast as direct drive which means the blades don't flatten out like DD units. Plus quieter. Just make sure you get a "thermal" style clutch which as a spring on the front as opposed to a non thermal which has no spring. Thermal units work better.

 

[turbine68rt]

Clutch type fans pull more air as they don't rotate as fast as direct drive which means the blades don't flatten out like DD units. Plus quieter. Just make sure you get a "thermal" style clutch which as a spring on the front as opposed to a non thermal which has no spring. Thermal units work better.

Been running a non thermal for over 30 years and it tops out at 180 even sitting in traffic. Love it. I was just curious if cars like mine came with them or the DD.

 

[ckessel]

I tried the non on my Duster years ago, had issues. Went with thermal, no issues. Could have been a defective unit. On the DD fans, you'll need some extra fan to radiator clearance as when the RPM's go up, the blade tips pull forward. Potential disaster if not taken care of.

 

[famous bob]

Clutch type fans pull more air as they don't rotate as fast as direct drive which means the blades don't flatten out like DD units. Plus quieter. Just make sure you get a "thermal" style clutch which as a spring on the front as opposed to a non thermal which has no spring. Thermal units work better.

I tested fan combinations all last summer , a clutch type fan ''does not'' pull more air than a direct drive fan, on mine its about 6-8 degrees better w/ a direct drive , I only stuck w/ the clutch type for the small perf. gain . Noise is of no concern on mine ------------

 

[ckessel]

Nice to get feedback from a real world test.

 

[moparedtn]

So many factors determine how much cfm a given fan will potentially flow - some of
the aftermarket will actually advertise that cfm on their stuff, in fact.
Size, blade pitch, number of blades, shape of fins - so many factors.
I only run a direct drive on Fred because there simply isn't the room for a clutch setup
(Griffin fat-*** radiator).

 

[RJRENTON]

Clutch type fans pull more air as they don't rotate as fast as direct drive which means the blades don't flatten out like DD units. Plus quieter. Just make sure you get a "thermal" style clutch which as a spring on the front as opposed to a non thermal which has no spring. Thermal units work better.

Not necessarily accurate information.....the amount of air moved is in direct proportion to the number of blades, the diameter of the fan assembly, the pitch angle of the blades, if the individual blade is an air foil design and the RPM of the blade assembly at a specific RPM. Torque drive fan clutches tend to stay engaged for a longer time b4 achieving the limiting RPM. Thermal drive fan clutches sense air flow temperature and, depending on the calibrated RPM and temperature relationship, usually, dis-engage at a lower RPM than the torque drive fan clutch. IF Actual AIRFLOW is measured, then the torque drive fan clutch will likely move more air flow, becsuse it remains engaged at lower RPM level. For example, Mopar's HP engines, 426 Hemi and the 440 +6 engine and the 340 HP, had torque drive fan clutches as origional equipment. Just my opinion of course.
BOB RENTON

 

[ricks_RR]

i like DD fans they work a cluch fan if is dont work right you start to over heat . DD fan works all the time

 

[RJRENTON]

i like DD fans they work a cluch fan if is dont work right you start to over heat . DD fan works all the time

True.....but as RPM's increase, the direct drive fan's horsepower requirements increase as a cube function of the rpm differences. See fan law #3 below. Both the torque drive and the thermal drive clutches limit the fan's RPM and therefore the horsepower required to turn the fan. Its sort of equilivant to waisting HP.
Just my opinion of course. But do the math for yourself.
BOB RENTON

 

[ricks_RR]

i see but i want that motor to run cool all the time . my 69 383 runner runs 180 and 190 going up hill and right back to 180 when running on flat ground no matter how hot it is out side

 

[62 Dart Convertible]

Clutch type fans pull more air as they don't rotate as fast as direct drive which means the blades don't flatten out like DD units.

This is not true at all.