viscous fan drive

[hotrodstude]

why bother just put a regular flex fan on the engine. you may need a shroud.but i have never had any problems with this system.works for me.

2006,f-150,2x4,v-6,5-speed manual,8ft bed, will post stude info when i get it on the road.

[Alan]

Off the 425, 472, 500 CI. Don't try the ones off the 4.1 aluminum motor.

[maxpower1954]

Thank you! Russ Farris

[alpayed]

I am a bit confused here. The fan as mentioned by Bob (above) installed on my Hawk works differently to what is described above.
When cold it simply freewheels. As the engine temperature rises the thermo spring on the front which is subject to the hot air coming through the radiator activates the coupling (progressively) When it is very hot the coupling is almost locked giving the most cooling.
To my way of thinking you should be able to spin fan freely, (or with little effort) when the engine is cold. Only when it is hot do you need cooling.
Allan

[64V-K7]

Speaking about function....
I HAD a straight 6 blade fan on my GT Hawk and at road speed, was pretty noisy (3.31 rear).

Earler this year, a T-bow viscous fan coupling and 6 blade, was installed because I wanted to reduce noise and I knew the viscous part would reduce the rpm of the fan, which it does.

But, the fan turns with the engine, all the time. It just turns slower because of the fluid medium. When its hot, the fluid is thinner, but it still pulls a lot of air and the speed and fluxuates with engine rpm.

I believe the point of a viscous coupling is ONLY to reduce the fan speed and allow a larger fan to pull more air thru the radiator.

The function of a thermostatic coupling should be more akin to what Alan said, however, I just gave an original 63 Lark fan/thermostatic clutch to a friend. It was in prime condition and did have a definite resistance to turning it by hand.

Once both types of couplings are functionally worn out, the fan will spin, but do no work or very little. At that point, it is no longer being driven by engine force, just going along for the ride due to frictional reasons.




Bob Johnstone

https://www.studebaker-info.org

64 GT Hawk
55 President State Sedan
70 Avanti (R3)

[Bob Bryant]

Not sure if this info is helpful. My viscous fan clutch on my Avanti R-1 was tired. I bought a used unit which did not work as well as the one it replaced, so I changed to a bi-metallic clutch.

In 2006 it was my understanding that viscous fan clutches were no longer available and new units off the shelf of the vendors I contacted were bi-metallic. Both types were referred to as Part #1560257. My new unit needed a little filing, as the milling of the slots for the bolts attaching it to the water pump had not removed quite enough metal. Obviously, there can be some NOS viscous units out there if you can locate them.

It would be interesting to know the manufacturing source of the bi-metallic clutches.

"It's like deja vu all over again."--Yogi Berra

[Dan White]

Bob I think you have it reversed. Bi-metallic or thermostatic whatever you want to call them are no longer available. There may be some NOS out there somewhere but I have not seen any. All the vendors to my knowledge are selling the viscous coupled units now.

Dan White
64 R1 GT
64 R2 GT

[hotrodstude]

was the 6 -bladed fan fixed blades? i use flex fans no noise the fan flattens out at high rpm. the blades are flexable but you have to watch putting them on the edges are razor sharp.always wear gloves leather gloves.

2006,f-150,2x4,v-6,5-speed manual,8ft bed, will post stude info when i get it on the road.

[Bob Bryant]

Dan: Thanks for the clarification. My Avanti manual from SNM refers to a viscous fan drive and I assumed the manual content had not been revised. It describes the fluid as being silicone. I won't tell anyone again I have a thermostatic fan clutch! Bob

quote:Originally posted by Dan White

Bob I think you have it reversed. Bi-metallic or thermostatic whatever you want to call them are no longer available. There may be some NOS out there somewhere but I have not seen any. All the vendors to my knowledge are selling the viscous coupled units now.

Dan White
64 R1 GT
64 R2 GT

"It's like deja vu all over again."--Yogi Berra

[Jolly-John]

Hi, Gang. The Flex-Fan has another advantage no one has mentioned yet...its use significantly reduces the weight on the water pump bearing and shaft. This is especially important for the R series engines, where you have that heavy multi-groove pulley to contend with, plus the weight of the fan drive and the metal fan. I know the Avanti water pump has a beefed-up snout, but I still find the original R engine fan set-up is hard on water pumps.

I have two extra Flex-Fans available for purchase. One is new-in-box, and the other is an excellent used Flex-Fan. These are the genuine Flex-Fan brand, and have the correct diameter for our Stude V-8s. These are made totally of fiberglass (no razor-sharp metal blade edges). I have used these very successfully on my Avantis in the past. Just private message or email me, if someone wants more info, a photo, or a price for each. Thanks. John in Wisconsin

[bige]

I can't find any reading that suggests that what you are saying is correct.

I've never had a bad fan clutch allow the fan to continue its rotation on a hot engine when it's shut off nor a bad one stop spinning.

This has been my experience on both thermostatically controlled and RPM type. In fact it has been my experience only a month ago with a defective unit on my '76 Chrysler. Installed a new Evercool unit and noticed the car running hotter than before. After changing the thermostat because I assumed it was something other than the new fan clutch I relented and observed the clutch's operation when the engine was good and hot. It did exactly what a bad clutch will do, spin the fan much slower than a good one will and continue to spin when the engine is stopped. I replaced it and have a nice fast spinning fan, a cool engine and a clutch that locks up tight enough to halt the fan in 1/4 turn when I shut the car off.

I'd rather be wrong with a cool running engine than right overheated by the side of the road.

quote:Originally posted by Mike Van Veghten

That fan ISN'T nesessarally bad...!

A BIG question you didn't offer...and no one asked -
Was the fan hot when you noticed it running on?

That's what they are supposed to do when hot...!

When they are cold/cool, they are tight and...yes, should stop pretty quickly.
When hot, they loosen up and spin a few rotations after shut down.

Read up on them..

Mike

On its way to a 15.097 Island Dragway Great Meadows NJ Spring 2006.

[alpayed]

This link explains fairly well how the clutch/couplings work.

.http://www.aa1car.com/library/cooling_fan_clutch.htm

Allan

[60ragtop]

I installed a viscous drive and 5 blade fan on my 60 convertible to try to fix a problem with the engine running hot at idle, long stop lights, in traffic, etc. Problem not solved, but I noticed the fan continues to spin a few revolutions after the engine is shut off. Based on most comments here, this means the viscous drive is not working as intended. Correct? I only ask because there seems to be some difference of opinion.

[GTtim]

I think the link above summarizes it nicely, if the fan/clutch spins easily, it ain't workin.

Tim K.
'64 R2 GT Hawk

[60ragtop]

Yep, I shoulda read that before I posted....maybe one of those flex fans would solve the problem without undue noise. Not that I mind noise all that much.