7 blade fan with no fan clutch

[67mopar]

Hi all
JayCee (67 Chrysler Newport Custom 383) has a 7 blade fan but no clutch, should i change it to the 4 blade?

 

[413]

Why? Those move lots of air. But they rob power of you are going higher RPM

 

[Ross Wooldridge]

It can be done, but it will be LOUD, and power robbing. Designed to run with a thermal clutch assembly.

 

[thrashingcows]

Yup I've run the 7 blade with no clutch...noisy as all heck! But they do move a ton of air and keep things cool...with the proper fan shroud in place that is.

Any reason you can't run a clutch on your car? Even the weird off set 5 blade fans used on the RWD mopars in the late 70's and into the 80's move a ton of air and are relatively easy to find.

 

[CBODY67]

I have seen some pictures of a 7 blade non-fan clutch situation in some sales brochure engine pictures. Seems like they were 440s in about 1968 or so?

 

[1970FuryConv]

Hi all
JayCee (67 Chrysler Newport Custom 383) has a 7 blade fan but no clutch, should i change it to the 4 blade?

I vote NO.
7-blade fan gives much more air-draw through the radiator. Makes engine cooler and happier.
Important, your fan spacer, between fan and water pump, needs to put the fan about 1.0-1.5" from the radiator if you have no fan shroud.
If you have a fan shroud, the back of the fan blades need to protrude a little beyond the back of the shroud.

 

[Gerald Morris]

I've got a straight 7 blade, 18 inch salad chopper that came with Gertrude, another 6 blade one from Mathilda, and have but a week ago put a clutched 7 blade 18 inch fan on Gertrude. The straight fan sat just 0.25 inches from the radiator, sans shroud. Same with Mathilda when I got her w the 6 blade fan. These cars didn't always come with shrouds.

I fabricated a NICE shroud for Mathilda last Spring, but we know what came of it later that summer. It helped, but the cheap A Team electric fan helped more. For the dollar, I find this to be so, and will stick by that assessment.

7 blade fans move PLENTY air, when they're turning, but I'm more apt than ever to be RID of mech fans altogether and might even ditch the clutch fan I just installed, if the nice new FFD 3600 I installed a couple days ago will do for it well enough.

Mind you all, 75% of my time behind the wheel is in urban traffic under 40 mph, so electric cooling makes more sense in this environment. On the highway, a clutch fan certainly pulls air, though once rolling above ~40 mph, the headwind will cool the radiator nicely without any fan.

For now, I've saturated the amount of air I can push or pull through that radiator, and am looking into increasing the flow rate at low rpm. The non-AC, 4.375" 8 blade impeller iron pump I installed with the clutched salad chopper moves coolant a bit quicker, which has helped reduce my average running temperature by 15 degrees Fahrenheit, when rolling.

 

[MrMoparCHP]

How I have seen it.
4 blade solid - Non AC / Non Cooling Package
7 blade solid - Non AC / Cooling Package
7 blade clutch - AC

Just my observation, not set in stone.


Alan

 

[fury fan]

Old post , but:
FWIW - my 65 Sport Fury 383-4 ran quite cool with a 4-blade fan.
And be very watchful if buying a new replacement fan - the Magnum engines used a 5-blade metal fan with clutch, much like the old Mopar Performance fan kit - but the Magnum fan is reverse-rotation.