fan clutch

[bkahler]

With all the talk recently about people being worried about over revving their engines while driving. It sounds like a lot of the concern is based on what might be the sound of the engine fan turning at 3200 rpm.

I know on our motorhome it definitely makes a difference. You can certainly tell when the clutch kicks in and the fan is engaged. It sounds like the engine down shifts when the fan clutch kicks in.

So what I'm wondering is if anyone has fitted a fan clutch with fan in place of the original fixed fan and if so how'd you do it?!

Thanks,

Brad

[Merle Coggins]

I thought about that too, but I don't think there's enough room in there for a clutch fan.

Merle

[Guest Dave Claussen]

There might be room if you were to move the radiator in front of the radiator support-I think. This might be a little extreme but I have read on other posts about moving the radiator forward to make room for a longer motor, either a longer 6 cylinder or a V8. I have not tried this but if I'm sure I've seen accounts of others doing it with success. Dave

[grey beard]

Yes, I have seen the longer 25-inch blocik installed in Pilothouse applications with this mod to the radiator, so it stands to reason that Dave is right - should net two extrra incheds of space one could use for a fan clutvch, as well.

Whilse working for a Natrional Lease fleet account back in the seventies, I attended some schools on truck noise abatement. The research they cited pointed to the fan as the number one noise culprit on semi's. We all know how much quieter diesels on the higfhway are today, and my understanding is that this was accomplished through two avenues - fan clutches and tire technology - both of which are certainly availabvle to us in the Pilothouse fraternity.

I have read over the archives in this forum, and to my best knowledge this is the first post on this issue. If you pursue the subject, please let us know what fits, and or course, how it works from a sound perspective.

Wouldn't it be nice to drive a Pilothouse at 3200 rpm . . . . . . quietly?

I think this is a great idea.

Thanks for sharing it with us.

[Don Coatney]

I have no fan noise as I have no belt driven fan. I installed a thermostically

controlled electric pusher fan. At speeds above 35-40 MPH there is no need

for a cooling fan even with 95 degree ambient temperatures. My electric fan

kicks on when the engine temperature exceeds 185 degrees. I am very happy

with this setup.

[bkahler]

Thanks for the replies. I don't as yet have my radiator installed so I had no way of knowing how much space was available between the water pump flange and the radiator core.

While I'm not overly interested in modifying my truck to install a fan clutch (at least not until I get it done and driveable first!) I do plan on looking into the options with the various fan clutches that are available on the market just to see if anything might even be close to working.

If or when I get around to this effort I'll definitely keep the forums updated.

Have any of you heard of or used "flex" fans? I have seen a few where the blades seem to flatten out once the fan speed gets up above a certain rpm. I wonder if a flex fan might be a partial solution to the noice issue.

Also I keep thinking back to how variable pitch propellers operate. I would think something like that might be a potential solution as well.

Any thoughts?!

Thanks!

Brad

[grey beard]

Hey Don,

That is NEAT! Ddid yo u have the opportunity to drive the unit both with and without the mechanical fan? How much difference did it make in cabin noise from the engine? I would think it should be appreciable.

Next question - do any of the aftermarket retrofit shops offer a sox-volt fan of the sort you employed? That is what I will need to copy your efforts.

Thanks for the idea. I like!

[Don Coatney]

Hey Don,

That is NEAT! Ddid yo u have the opportunity to drive the unit both with and without the mechanical fan? How much difference did it make in cabin noise from the engine? I would think it should be appreciable.

Next question - do any of the aftermarket retrofit shops offer a sox-volt fan of the sort you employed? That is what I will need to copy your efforts.

Thanks for the idea. I like!

Dave;

I installed this electric pusher fan as I did not think

I would have enough real estate between the water

pump and radiator to install a conventional fan.

Remember I have a long block Desoto engine in my

P-15. I did plan this out early on once I made the

decision to go with the long block. My fan and

controller are 12 volt. There are 6 volt fans

available as a quick google produced several hits.

However finding a 6 volt thermastatic controller

that will operate in the desired temperature ranges

may be a problem. It took me a while to find one

that would work for me.