BearKiller

Surely there are applications for the B-series Cummins engines that do not use a clutched fan.

Can someone point me in the direction of a source for direct-drive fan hubs; or, clue me in on some specific models of equipment or whatever that did not use a clutched fan hub ??

Many thanks.

jrs_dodge_diesel

Industrial engine applications (compressors, pumps, etc) might have the direct drive you seek.

Hvytrkmech

You can manually engage the fan that has a fan clutch, once you do this it will always be on. Pull the metal plate or spring assembly on the front of the viscous drive clutch, then pull out the small metal pin. The fan clutch should lock up and stay locked up.

BearKiller

You have my attention !!!


Can this be done effectively to a clutch that is otherwise no good ??

Can you show this to me in pictures ??

Thanks.

Hvytrkmech

I will be at the shop on Wednesday and will dig up the clutch assembly and snap some pics.

BearKiller

That would be much appreciated, thanks.

Stamey

You probably don't want to lock up your clutch permanently. Last year I bought a 1996 F500 with a 12v in it, at auction. The truck ran great, but when I drove it home I could not get over 53mph, empty, going downhill with a tail wind. This was about 2000 RPM. I thought, oh man, I'm gonna need to get some governor springs in this thing quick, because Ford really had them turn this engine down.
Well, actually, no, that wasn't the case. Once I got it home I found that the fan clutch was locked up on it. I still had not made a connection, but replaced the fan clutch as a matter of course.
Once the new fan clutch went on, suddenly the engine would turn 2700 RPM, even with a load, going up hill. It now can do a little over 70mph.
What I learned from this is the fan in a clutched system is designed to move so much air that it really puts a load on the engine when it is engaged, so much that the engine RPM is limited. This will likely be the case for you, if you lock your fan clutch. Engines that do not have fan clutches have differently designed fans, so that they do not pull so much power from the engine. An example would be a stationary engine that always needs the fan moving air through the radiator.
Of course, if you change the fan to something from a stationary engine (they use Cummins 5.9's in Gensets and chippers), you'd be OK because the fan was designed to put less load on the engine while getting the air moved.

Chris

G1625S

I think bearkiller has all the clutches on his trucks pinned--it's just the way he rolls

BearKiller

You got it.

Actually, I keep two seperate clutches for each engine, a pinned one for summer and an un-pinned one for winter.

Contrary to Stamey's experience, I can see nor feel no difference whatsoever in power or mileage between running either --- all with a stock fan; if it can pull eighteen big Charolais cows up Russell Creek Hill, it ain't gonna notice a little old fan.

All over the internet, I read of all manner of various vehicle owners that are trying all sorts of remedies to keep their fans locked up at idle speeds and when sitting in traffic.

My reasoning is, everything I ever owned that was made before 1985 has had no fan-clutch whatsoever and they all seem to get along fine without the inconvenience, so why not just eliminate the clutch and go direct-drive.

I am looking forward to experimenting with Hvytrkmech's solution.

cincydiesel

Well this thread got my attention.. I'm on my 3rd clutch and its gone already. I was not looking forward to replacing that thing again. Cant wait for some pics Tim

Fishguy 50

A direct drive fan "IS" going to "SIGNIFICANTLY" reduce your MPG. PERIOD!

Hvytrkmech

Guy's, I dug up and boxed the fan clutch and forgot it at the shop. I made a reminder note so you will have the pics and write up on it tomorrow.

Sorry,

rebal

I need to find the article in MOPAR MUSCLE! mag. it had a test done on this with different engines as I remember having a full lock up fan robbed the Engine of 1 HP verses clutch. and fuel consumption was minimal .

Stamey

Just keep in mind that how much power the fans robs depends on its design. In the case of my dump truck, and my Dodge's, that plastic fan is huge, and really moves some air when it is moving at engine speed. Older vehicles with a metal fan did not have as aggressive a style, and while the clutch may have helped fuel mileage a little, it didn't make much difference either way.
My dump truck was the first case in which I encountered the fan putting so much drag on the engine as to limit its RPMs. Never had a bad clutch on the Dodges, so I don't know, but I'm betting I'd see similar behavior.


Chris

Mexstan

Somebody correct me if I am wrong, but isnīt the clutch electricaly operated via a switch at the bottom of the rad? If that is the case, then why canīt you bypass the rad switch and install a manual switch in the cab?