Clutch Fan!

-
xLURKxDOGx

xLURKxDOGx

"An angel fat, at satan's feast"
Joined
Dec 27, 2013
Messages
4,361
Reaction score
1,754
Location
PHX
Is anyone using one of these on their slant and if so is it a better alternative than the Flex fan?

I was looking at one of these.


[ame="http://www.ebay.com/itm/1968-72-Mopar-BB-Fan-Blade-w-Thermal-Clutch-4266933-H-/111348836946?pt=Motors_Car_Truck_Parts_Accessories&hash=item19ece86a52&vxp=mtr"]1968 72 Mopar BB Fan Blade w Thermal Clutch 4266933 H | eBay[/ame]


Thanks,

Jake.
 
First, don't buy the one you have a link to. Way too pricey. You can find one here on the forum a lot of the time or get a new one at Jegs or Summit for a better price.

As for better, they all cool but the clutch fan will disengage at high speed since the air flowing through radiator is supplied by forward motion and free up a little horsepower. Still, not enough to get overly exited about. Stick with what ya got if it's working. Spend your money elsewhere. Dennis
 
You can get the nice MP unit from Summit for like 115 NEW.
 
When I tried to install a Mopar Performance 5 blade clutch fan on the wife's 73, slant 6, non-AC, standard cooling, it wouldn't fit.

I can't remember what the problem was, may have been hitting the upper hose or to close/hitting the radiator.
 
valiant1966 said:
First, don't buy the one you have a link to. Way too pricey. You can find one here on the forum a lot of the time or get a new one at Jegs or Summit for a better price.

As for better, they all cool but the clutch fan will disengage at high speed since the air flowing through radiator is supplied by forward motion and free up a little horsepower. Still, not enough to get overly exited about. Stick with what ya got if it's working. Spend your money elsewhere. Dennis
Click to expand...



Thanks for the info Valiant66! I was looks at those one on summit but the link wasnt working to post here. I think thats the one!!!!


Thanks,
Jake
 
You may be able to get away with the Jaguar clutch and a smaller diameter fan blade.
Clutch and fan can be purchased separately as you probably know.
I have run a thermostatic clutch fan on 20 of the 21 vehicles I owned and they are rock solid reliable from my experience.
 
I had one on my old 71 Swinger. Worked great. While in service I drove a 78 dually with 440 and clutch fan. Thing sucked gas until a turbo muffler was put on. One time coming back to base after a job, all of a sudden heard a horrendous noise from under the hood. Quickly followed by an interior filled with fog and stinking of anti freeze. There was a one shop town with a population of mmaybe 10
 
A clutch fan is better than a flex fan, but don't know if one would fit a slant. The engine is longer than a V-8, so less room to the radiator. Maybe Volare or Aspens used them. I can't fit even a regular factory fixed fan in my slant since the p.o. put in a non-Mopar radiator. It hasd a pusher electric fan (M-B) and no mechanical fan. I could fit a thin Summit nylon fan. A small mechanical fan, plus an electric should work fine and be efficient.

Besides the Jaguar clutch fan mentioned, perhaps one from a M-B like an 82-85 300D would fit. Euro clutch-fans are much narrower. I tested a Mopar clutch on my 300D and it fit the water pump, using a bushing that came in the box, so a 300D clutch fits a Mopar water pump if you drill the center hole bigger (small block, probably same for a slant).
 
BillGrissom said:
A clutch fan is better than a flex fan, but don't know if one would fit a slant. The engine is longer than a V-8, so less room to the radiator. Maybe Volare or Aspens used them. I can't fit even a regular factory fixed fan in my slant since the p.o. put in a non-Mopar radiator. It hasd a pusher electric fan (M-B) and no mechanical fan. I could fit a thin Summit nylon fan. A small mechanical fan, plus an electric should work fine and be efficient.

Besides the Jaguar clutch fan mentioned, perhaps one from a M-B like an 82-85 300D would fit. Euro clutch-fans are much narrower. I tested a Mopar clutch on my 300D and it fit the water pump, using a bushing that came in the box, so a 300D clutch fits a Mopar water pump if you drill the center hole bigger (small block, probably same for a slant).
Click to expand...


I wasnt sure if it would fit but it looked like it might be really close so i thought id ask. I bought a new champion aluminum radiator with a fan but didnt realize you need brackets or something to hook it up so i thought this might be a better alternative. Do you need a relay or can you hook the electric fan up straight to an ignition source?


Thanks everyone!!

Jake
 
An electric fan needs a controller. Hayden makes several models. The best type have a coolant temperature sensor that screws into a pipe thread (~1/4 NPT). Cheaper ones have a sensor you push into the radiator fins. I got a few of the better ones for $25 on rockauto a year or so ago, but usually see ~$55. The Hayden ones usually come with an integral relay and have an adjustment for the temperature setpoint. You could also wire to a manual switch in the cabin, if you want to play "man in the loop controller".

Simplest is to wire it to IGN1, so always on w/ the engine but not directly or you will melt your key switch and/or bulkhead connector. Use a relay. A cheapie fan can use a normal 40 A automotive relay. Bigger fans might need a bigger relay. My 02 Chrysler minivan uses a solid-state relay for the 2 fans, which should work (see rockauto). Same basic hookup as a normal auto relay.
 
I feel that clutch fans are the best choice there is as far as cooling fans are concerned.

Flex fans have a couple inherent problems. The first is that they spin proportionally to the engine rpm and have been known to abruptly disintegrate if subjected to high rpms consistently.

The second issue is that flex fans flatten out and stop moving much air at higher rpms. So, if you have a high-load, slow speed situation where the engine is working hard at higher rpms, the fan will not move enough air. That's why you NEVER see trucks and vans with a flex fan. They all have clutch fans, at least after air conditioning became common.

I personally am unconvinced that electric fans are worth the trouble. You have to have a large enough fan(s), all the wiring and a controller, and I don't think it's free horsepower. The alternator has to keep the battery charged, and that takes engine power to do so. The main reason the OEM's used electric fans was space considerations.

The clutch fan loafs along undriven until the temp rises, at which point it engages, and I find that roar comforting, not annoying because I know it's pulling loads of nice cool air through my radiator.

Be aware that there are two variations of fan clutches- thermal and non-thermal. The non-thermal do not respond to temp variations and stay about 80 percent engaged all the time.
 
BillGrissom said:
An electric fan needs a controller. Hayden makes several models. The best type have a coolant temperature sensor that screws into a pipe thread (~1/4 NPT). Cheaper ones have a sensor you push into the radiator fins. I got a few of the better ones for $25 on rockauto a year or so ago, but usually see ~$55. The Hayden ones usually come with an integral relay and have an adjustment for the temperature setpoint. You could also wire to a manual switch in the cabin, if you want to play "man in the loop controller".

Simplest is to wire it to IGN1, so always on w/ the engine but not directly or you will melt your key switch and/or bulkhead connector. Use a relay. A cheapie fan can use a normal 40 A automotive relay. Bigger fans might need a bigger relay. My 02 Chrysler minivan uses a solid-state relay for the 2 fans, which should work (see rockauto). Same basic hookup as a normal auto relay.
Click to expand...

Thanks for the info BILL!! I just got wiring set and im looking forward to putting it in. Also, i noticed a couple of guys mentioning how a belt fan robs you of quite a bit of power and stirs a bit of turbulence under the hood and thats to be expected i guess. Do you get more cooling of the engine with that turbulence or is it just a wasted byproduct?


Thanks,
Jake
 
You must log in or register to reply here.
-

Back
Top