cheech147 Posted June 2 Share Posted June 2 I have a 78 Mack F model with a 290 Cummins. It has a constant radiator cooling fan that sounds like a jimmy when I’m going through gears. I was going to see if they made a clutch fan for that generation and was also thinking electric. Anyone out there in Mack land have any ideas or suggestions? Quote Link to comment https://www.bigmacktrucks.com/topic/74219-78-mack-f-model-with-290-cummins/ Share on other sites More sharing options...
BOBWhite Posted June 2 Share Posted June 2 Electric clutch fan or electric fans? I've haven't heard of many electric clutch fans and electric fans are a bad idea on anything this old with wiring and such. I would try and go with an air clutch like a Horton, they are available everywhere but adapting might be tricky. You could also go with a viscus clutch but you can't flip those on with a switch (switchable fans are nice if you don't have jakes). Quote Link to comment https://www.bigmacktrucks.com/topic/74219-78-mack-f-model-with-290-cummins/#findComment-552945 Share on other sites More sharing options...
Popular Post Geoff Weeks Posted June 2 Popular Post Share Posted June 2 (edited) Facet made electric fan clutches for trucks, My Marmon with a 3406B had one. Simple and worked, took utility trailer bearings and was easy to rebuild. Unfortunately parts are non existent. Namely clutch plate. Any Cummins 855 should be no problem fitting a Horton air clutch. The conversion will likely require a new fan and some plumbing, you might get lucky and be able to reuse the fan, but the mount an pulley will need to be changed. Electric motor driven fans just can't move enough air for a hard working big bore diesel. Edited June 2 by Geoff Weeks 3 Quote Link to comment https://www.bigmacktrucks.com/topic/74219-78-mack-f-model-with-290-cummins/#findComment-552951 Share on other sites More sharing options...
mechohaulic Posted June 2 Share Posted June 2 I'm not understanding the "sounds like a jimmy" part. which brings couple questions . 1- how is the engine running temp wise ? 2- could radiator need a cleaning on fins causing fan to work harder? I would go with a horton having electric fan control switch in cab. might be able to change fan from all steel to steel/ plastic combo. Quote Link to comment https://www.bigmacktrucks.com/topic/74219-78-mack-f-model-with-290-cummins/#findComment-552953 Share on other sites More sharing options...
mowerman Posted June 2 Share Posted June 2 Yes, Mecho, I’m sure we were all wondering the same thing. What does that supposed to mean ????? Sounds like a Jimmy…. Older Cummings .. fan had pretty loud howl to them I ran a lot of them back on the 70s… Quote Link to comment https://www.bigmacktrucks.com/topic/74219-78-mack-f-model-with-290-cummins/#findComment-552972 Share on other sites More sharing options...
h67st Posted June 3 Share Posted June 3 We need photos of this truck! You don't see a lot of F models around these days. 2 Quote Link to comment https://www.bigmacktrucks.com/topic/74219-78-mack-f-model-with-290-cummins/#findComment-552986 Share on other sites More sharing options...
cheech147 Posted June 3 Author Share Posted June 3 What I meant by sounds like a jimmy, is as one poster stated stated loud howling whine. I was just making a comparison to loudness of the old jimmy. Quote Link to comment https://www.bigmacktrucks.com/topic/74219-78-mack-f-model-with-290-cummins/#findComment-553040 Share on other sites More sharing options...
mowerman Posted June 4 Share Posted June 4 Ooooooooooooooo ok gotcha the Mack blades usually have soothing lower tone deeper howl especially with the shutters closed I don’t know anything about them electrics by Mechohaulic says they’re available. Good luck I would try Google search first… bob Quote Link to comment https://www.bigmacktrucks.com/topic/74219-78-mack-f-model-with-290-cummins/#findComment-553074 Share on other sites More sharing options...
mowerman Posted June 4 Share Posted June 4 Actually, my R model Western was like that and it had the Mack engine in it. I don’t know why it was so loud … maxidyne on top of that so I was constantly winding it out very annoying.i get your complaint … bob Quote Link to comment https://www.bigmacktrucks.com/topic/74219-78-mack-f-model-with-290-cummins/#findComment-553075 Share on other sites More sharing options...
Freightrain Posted June 7 Share Posted June 7 Are the shutters closed a lot due to no load on it? My shutters will close at times running down the highway(cool nights) and will get it sounding like a jet engine of sorts drawing against a closed radiator. 2 Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/74219-78-mack-f-model-with-290-cummins/#findComment-553201 Share on other sites More sharing options...
cheech147 Posted July 1 Author Share Posted July 1 No shutters Quote Link to comment https://www.bigmacktrucks.com/topic/74219-78-mack-f-model-with-290-cummins/#findComment-554560 Share on other sites More sharing options...
Lmackattack Posted July 1 Share Posted July 1 I'd assume you could put a mechanical fan clutch on the 290. My 77' maxidyne had a fan mounted directly to the pully. I was able to put a fan clutch on with no other modifications. It greatly reduces noise and gives you about 10hp back to drive the wheels 2 Quote Link to comment https://www.bigmacktrucks.com/topic/74219-78-mack-f-model-with-290-cummins/#findComment-554566 Share on other sites More sharing options...
Lmackattack Posted July 1 Share Posted July 1 Check out ebay . https://www.ebay.com/itm/355759405070?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=v0muxadktfq&sssrc=4429486&ssuid=B7peNTQaQY-&var=&widget_ver=artemis&media=MORE 1 Quote Link to comment https://www.bigmacktrucks.com/topic/74219-78-mack-f-model-with-290-cummins/#findComment-554567 Share on other sites More sharing options...
Vladislav Posted July 1 Share Posted July 1 4 hours ago, Lmackattack said: Check out ebay . https://www.ebay.com/itm/355759405070?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=v0muxadktfq&sssrc=4429486&ssuid=B7peNTQaQY-&var=&widget_ver=artemis&media=MORE Isn't that the same part as was used on Mack engines? E6-350 particulary. Quote Никогда не бывает слишком много грузовиков! leversole 11.2012 Link to comment https://www.bigmacktrucks.com/topic/74219-78-mack-f-model-with-290-cummins/#findComment-554574 Share on other sites More sharing options...
Geoff Weeks Posted July 1 Share Posted July 1 Before I spent $200 on that one ($100 +$100 shipping) I'd look at either a "front air Kysor" (which was designed as a replacement for a fixed fan) which can use the original fan drive, or replacing the drive with a whole air clutch. Problem with those viscus drives is: they wear out and hard to tell what you are buying, and very hard to find a new replacement when they do fail. Depends on your plans are for the truck. An Air clutch will cost slightly more, but are rebuildable. I had both Bendix and Horton and both were good. Bendix has some advantages but parts are harder to find. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/74219-78-mack-f-model-with-290-cummins/#findComment-554575 Share on other sites More sharing options...
Lmackattack Posted July 1 Share Posted July 1 8 hours ago, Vladislav said: Isn't that the same part as was used on Mack engines? E6-350 particulary. Not sure. It looks very similar to mine but not sure if the cummins have different fan mounting bolt spacing. Quote Link to comment https://www.bigmacktrucks.com/topic/74219-78-mack-f-model-with-290-cummins/#findComment-554591 Share on other sites More sharing options...
Vladislav Posted July 1 Share Posted July 1 Just now, Lmackattack said: Not sure. It looks very similar to mine but not sure if the cummins have different fan mounting bolt spacing. Agree. The mounting flange and the pattern look very similar to what I had off my engine. But I didn't take any measurements and the offset may differ too. Quote Никогда не бывает слишком много грузовиков! leversole 11.2012 Link to comment https://www.bigmacktrucks.com/topic/74219-78-mack-f-model-with-290-cummins/#findComment-554593 Share on other sites More sharing options...
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