Already had a lwp setup including brackets.......installed on 67 Chevelle, not enough room for clutch fan..............have found a 6 blade 17" clutchless fan that will fit....just wondering if anyone else has done this and does it cool, with a shroud, or without one...................thanks.

I had a buddy put a flex fan on a 383 last week. The hood now has hole in it.:D The fan came apart.:yes:

This is not a flex fan, from talking to the owner of this shop, it is made out of steel, same as regular chevrolet fans, but with holes configured to fit straight onto pulley...original for V-8 Chevy 2

Already had a lwp setup including brackets.......installed on 67 Chevelle, not enough room for clutch fan..............have found a 6 blade 17" clutchless fan that will fit....just wondering if anyone else has done this and does it cool, with a shroud, or without one...................thanks.



I do. 67chevelle 427 LWP, stock radiator, charging system moved over to the pas side

I'm running a steel 15in 5 blade fan from Speedway Motors no shroud at this time. I have absolutely no running hot, or over heating problems on the freeway or in stop and go traffic. I have a 195 t-stat, and the temps never go over 210*. 95 percent of the time its stable between 195 and 200 degrees.

Also I ran a 17in 6 blade flexfan with the same results but I'm not sure though if it will fit inside my shroud. I'm not even sure my shroud will fit with a LWP setup with the 15in fan, I guess I should try it some day. IF I remember correctly the flex fan blades were very close to touching my alternator the way the blades were curved, so I went with a 15in fan

If your interested I'll get you the part number from Speedway it's a nice fan it really moves air.

I've never been a fan (no pun intended) of clutch fans I can get them to work but I never liked the wild temp swings that they can produce from time to time. My water temps are very stable staying within that 10 degree range. The only time temps move up towards 210 is when its like 95 degrees outside in city traffic with stop and go lights.

Also as you found out, there really isn't enough room for a clutch fan with a long water pump setup with a stock radiator location. Your 17in should work fine unless you have some other hidden problem. Timing is a major factor in eliminating hot run conditions, base, total and vac adv, and to a certain extent carb setup.

Hope it helps

Trivia:
In the late 60s & early 70s, NO- BIG CUBE--HIGH HP. car left Ford-G.M.-Mopar with a direct drive cooling fan. They ALL had clutches.
A clutch driven fan will not spin over 3-4 grand. When the engine is spinning 6 grand. At 6 grand with a direct driven fan blade the water pump is trying to fly away or be pulled off the front of the block.

I have a Mopar dyno test story from 1969-70. The engine used in the test was a 426 Hemi. The 426 gained 16.2 HP. using the Mopar Clutch on the fan blade. If you are going to use a direct drive cooling fan on a engine that may see 6000 RPMs. I would suggest a scatter shield on the front of the block and over the fan blade.
Ask the Mfg. if the fan blade you want to use, Is designed to operate at 6000 Plus -RPMs. Do your homework then decide........
Bob

Trivia:
In the late 60s & early 70s, NO- BIG CUBE--HIGH HP. car left Ford-G.M.-Mopar with a direct drive cooling fan. They ALL had clutches.
A clutch driven fan will not spin over 3-4 grand. When the engine is spinning 6 grand. At 6 grand with a direct driven fan blade the water pump is trying to fly away or be pulled off the front of the block.

I have a Mopar dyno test story from 1969-70. The engine used in the test was a 426 Hemi. The 426 gained 16.2 HP. using the Mopar Clutch on the fan blade. If you are going to use a direct drive cooling fan on a engine that may see 6000 RPMs. I would suggest a scatter shield on the front of the block and over the fan blade.
Ask the Mfg. if the fan blade you want to use, Is designed to operate at 6000 Plus -RPMs. Do your homework then decide........
Bob

The '70 LS5 car has had a mechanical fan on it since it was new. It has not blown up. No holes in the hood. It sees north of 6500 on rare occasions. But I do see where that could be a big concern for cars that see high RPM's quite frequently.

So my 350ci reving to 6500rpm all day long with a 4 blade steel propeller fan is a good idea? I wonder if it robs much power. Car certainly doesn't over heat, half filled brass rad and propeller aparently does a good job at cooling.

I agree that your 4 blade steel fan will work, WHY ? It is made from two pieces of stamped steel that are held in allignment with rivits. ( Nothing to come apart or metal fatigue)
A 3947772 stock 70 Chevelle fan blade has a stamped hub and the blades are rivited on to the hub, And they are designed to spin 3-4000 RPMs
I would guess if a 7 blade direct drive was the way to go, Forty years ago G.M.-Ford-MoPar would have done it that way.
Bob:thumbsup:

Bob, would the seven blade clutch fan move any more air than a seven blade mechanical fan? I know that is kind of a silly question given the obvious. But I remember you said something about the clutch fans moving more air, or the GM clutch fans moved the most cubic feet of air, or something to that effect.

The 7 blade gm clutch fan moves more air then the std issue 4 blade gm stock non clutch fan does esp when a hd or severe duty fan clutch is use with the 7 blade clutch fan.

And you always get better cooling when a shorud is uses to esp a idle in traffic.

A fan without a shorud pulls littl eto no air thur rad when at idle which isnt good for cooling at all.

Scott

I use an 18" Flex-a-lite fan (model #1318) on my BBC. I trimmed my shroud to allow the fan to be almost 2/3 out of the shroud at idle. It moves an incredible amount of air at idle & low rpm. The blades flatten out as rpm's go up so it's about half in/half out at cruise speed.

Had a 17" flexalite come apart and shred the hood in my Vette. When we put it back together I reused a new flex fan but keep the RPM below 6000. Am waiting for a new steel one with clutch :yes:

I had a buddy put a flex fan on a 383 last week. The hood now has hole in it.:D The fan came apart.:yes:

Had a 17" flexalite come apart and shred the hood in my Vette. When we put it back together I reused a new flex fan but keep the RPM below 6000. Am waiting for a new steel one with clutch :yes:

Alright, so this is causing me to think a little more about the flexi fans. My Chevelle will rarely see anything north of 5500rpm, not sustained anyway. How old were the fans that you guys mention in your posts? Were they used in a higher rpm application than what mine will see?

Alright, so this is causing me to think a little more about the flexi fans. My Chevelle will rarely see anything north of 5500rpm, not sustained anyway. How old were the fans that you guys mention in your posts? Were they used in a higher rpm application than what mine will see?

I am not sure how old the flex fan was when it came apart.
I had one on my Elco when I was 18, then the first cruise I went to, I heard lots of horror stories. So I took it off and thrashed it.:D

Mine was 3 years old with less than 10000 miles.
Even got Flexalite to pay for it and the damage.

OK if RPM is low.
I could never get an answer form them on safe RPM.

Rick's question concerning a LWP on a BB 67.
I have a 6 blade 17" fixed (not flex) fan I bought at the PeachState Show.
Nice meeting you there by the way.
I replaced the fixed 4 blade fan that I had in the car with this new 6 blade. Pulls a lot more air.
I have no trouble about overheating.
Only problem I had was that I had to trim a little on the top side of the shroud.
It's either a fixed blade or change out all to a SWP and find all the brackets, etc, to move your alt over or.......electric fan set up.
Hope that helps.

Nice to meet you too, always great to put a person to a name...we fired up the big block this past weekend with the fixed blade, no shroud yet, hope to buy one at Chevelleabration.......after timing was set, temp stayed around 195, no stat, with blower in front of radiator...3 core radiator seem to be doing good so far.....fan was not as noisey as i would have thought.....if it works, i save a bunch of coins on brackets....wish me luck..:thumbsup: