famous bob
mopar misfit
It's lighter, too.
I still don think they will cool as well as a 6 or 7 blade fan, they were made to keep fan noise down.
It's lighter, too.
Larry Shepard and his bunch discovered the five blade fan moved more air because it breaks the air up more since the blades are offset. Similar to the external fans on a GM alternator. Each blade is a different size. If you've ever looked at one, you know what I am talking about. The Mopar fan achieves the same effect since it's blades are offset. I'm no physicist, but it makes sense. I have actually proven it. I replaced a seven blade symmetrical fan with a five blade non symmetrical MP fan and the car ran cooler. Some people argue that a clutch fan cannot move more than a fixed blade, but that's false. The MP viscous fan is thermostatically controlled. It has a bimetal spring on the front that expands as it heats up. The fan can and will achieve 100% lockup under a heavy load as temperatures increase. The advantage they have is, they don't ALWAYS move the most air they can as the clutch allows slippage which saves horse power and increases mileage. It also reduces wear and tear on the water pump. Those old guys weren't stupid.
They really aren't THAT hard to find. If you have some GOOD yards around you, you should be able to find one. They were used on almost everything from the late 70s through the late 80s. The fan is the important part. You can get the clutch units new.
Factory flex fan Bob or aftermarket?Flex fans add heat to my set up---------
Thanks Jimacuda....someone saw this and hooked me up already.
Special thanks to fshd4it. An awesome member indeed.
Geesh....I guess you have...lol
I guess you are prepared for the zombie fan apocalypse. But at least you save something useful, not so much in my garage....
amen to that , I cut down studs to use ----------
I use bolts on mine. It helps to just get the bolts started first - like a thread or two on each. That'll allow you to pull the clutch out in order to fish them all in. Then use an open end wrench and snug them all down one flat a time. It's a shitty process, but it can be done.Bob, I am trying to put all the bolts in my Hayden 2947 fan clutch. It is more difficult than I even imagined. I had one bolt in for mock up before. I am trying your stud method now & that is even hard. Any other tips?
Yep. It's been described as "a real pain in the dick!" Pretty much sums it up.I use bolts on mine. It helps to just get the bolts started first - like a thread or two on each. That'll allow you to pull the clutch out in order to fish them all in. Then use an open end wrench and snug them all down one flat a time. It's a shitty process, but it can be done.
Interesting...When my 5-blade was destroyed by a General Lee-style crossing of some train tracks, I switched to a factory 7-blade and it pulls with noticeably more suction, at least just spinning at idle.It’s been said that the 5 blade moves the most air but if the 7 blade’s doing the trick why change it?
Bob, I am trying to put all the bolts in my Hayden 2947 fan clutch. It is more difficult than I even imagined. I had one bolt in for mock up before. I am trying your stud method now & that is even hard. Any other tips?
Yep. It's been described as "a real pain in the dick!" Pretty much sums it up.
Interesting...When my 5-blade was destroyed by a General Lee-style crossing of some train tracks, I switched to a factory 7-blade and it pulls with noticeably more suction, at least just spinning at idle.
I didnt use studs this time , I used a hair longer grade 8 bolt w/ a flat washer .
I cut the lip off of the back of my clutch ,about .100 , wish I`d have gone another .20 or .030, that lip doesnt do anything , and is just extra mat`rl.
I still had to install one bolt ,"leave ''unscrewed'' a bunch, to set the clutch groove in , to help get the fan in position, and rotated it around ,starting all the bolts w/ it way loose , and had to use needle nose pliers to get it in position ,( I WAS DOING IT W/ BURNED FINGERS ON MY RIGHT HAND). If u tighten one to far, u cant **** the thing out enough to get all of them started. w/o cutting the lip off , I doubt I could have done this ,then it would be back to using the studs , u can cut carburator studs to the exact length < trial and error .
Cutting the back of the clutch can be done easy in a lathe , my lathe took quite a bit of imagination because it wasnt big enought to swing the clutch over the cross slide , I would recommend having it cut by a machinist , would be ''no big deal.''
HANG IN THERE , ITS STILL A ***** !----LOL
Fantastic member fshd4it hooked me up with a 5 blade brand new in the box kit. Threw it on yesterday and tested it out for a few hours. That baby really moves some air. It’s hugely noticeable even at slow idle compared to the piece of crap flex fan that was on it. Constant cruising temp 182*, stop and go traffic drifts to 196* on an 86* day. No shroud yet but definitely considering it.
View attachment 1715542904 View attachment 1715542905
Factory flex fan Bob or aftermarket?
That’s close enough you don’t need a shroud.
Bob, I got it in, what an ordeal. I cut off some bolts like u suggested and used red locktite to hold them in the waterpump. I took the bolts out of the fan so it would tilt out of the way a little & give me a little more room. That made it a lot easier. I couldn’t get a lock washer on it, so I hope it it will stay tight. Looks like the slots in the clutch might dig in to the nuts and help.
I have a 7 blade fan. Looks like it would be easier with a 5 blade fan since they are asymmetrical and there are bigger spaces between some of the blades.
Having a bag of nuts helped cut down on the swear words, since I didn’t have to get under the car every time to look for a nut. I bet I dropped 30 or 40 of them.
I made a shroud out of a Ford Explorer shroud, and it is two piece, so I can install it last. That was very helpful as well. Don’t need anything else in the way to make it harder.
Machining of that ridge is a great idea, but out of my skill range. I wonder if Hayden ever actually installed one of these?
Thanks again for the help!
2 dif. aftermarkets , never seen a factory flex !!