clutch fan

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383Scampman

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Hi guys , just throwing it out there . I have a Scamp with a 383 A/T with a severe cooling problem . I have a 2 row radiator and a clutch fan . My question is : how do you test a clutch fan ? It isn't a viscous fan but a clutch fan that the car was born with . I am able to spin the fan by hand when the engine is not running . Is this normal ? Thank you , Tom
 
Bought a repop shroud from Classic Industries this week . Went to install it today and it's a no go . I have Schumacher mounts and the fan is offset to the right . I mocked up the shroud out of the car and all was o.k. , but no fit in car . Bummer or Bumma , as we say , in New England
 
First, make sure your engine tune is correct especially timing. You need to move coolant so consider a performance water pump. You could go with a 3 core radiator. Loose the clutch get a better fan, slight overdrive pulley. High flow lower temperature thermostat, all directionally correct!
 
when you say you have an extreme overheating issue. Can you explain what is happening? How hot are you getting? How long does it take to get to certain temps. Does the temps go up or down based on your speed?

Also, what is the tube size of the 2 row radiator? Popular sizes are dual 7/16", dual 1" and dual 1 1/4". If you have the dual 7/16", that could easily be your problem. If it is the 2 larger versions, then I'd have to hear what temps you are actually experiencing.
 
There are two types of clutch fans, thermal - has a bi-metal thermostatic coil spring; and non-thermal, no spring on the front. Which do you have?
 
Ccas is thinking. Demonic makes a good note in his question. I agree with Plymouth 65 on a 3 row.

How far offset is the shroud and how exactly is it not fitting in the car?

How is that 383 sitting in there. The Schumacher site has measurements for alignment purposes. (Not steering)
Photos?

I know there’s a lot of questions here for you to answer. Take your time.
 
383Scampman said:
I am able to spin the fan by hand when the engine is not running . Is this normal ? Thank you , Tom
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Tom, that will depend on how easy it is to turn and how hot the engine is as well as the clutch for the fan. They do wear out. Generally speaking, I would have to say “NO” to your question if the engine is up to temp.

MoPars replacement (IF you can get it!) is the best I have used. There viscous package.
Hayden also makes replacement units. You’ll ya ento measure yours up. There is a go to part number for a big block in an A body. I don’t remember it off hand. I’m sure someone will chime in with that parts number.
 
You really didn't give us any history on this problem. Did you just do this swap ? Did it ever run normal ? What do you consider hot ? 180 degrees, 200 degrees ? does it cool off back to "normal" when cruising over 40 mph ? Rear end gearing ? 3.23 ? 4.11 ? Coolant type and mixture. 50/50 ? Radiator cap tested ? 16 lb. ? As mentioned before, tuned properly ? All of these things can affect coolant temp.
 
First I want to thank everyone who responded . The radiator is #3574658 which is the radiator the car was born with . 318/A/C or 340 no A/C 2 row . After 5 minutes of running the temp goes up to 220 d. I have had the rad flow tested and it's fine . I have tried thermostats of 195d., 180d.,and 160d. I drained the coolant out yesterday and it was loaded with rust . The 383 is a mild performance motor with a clutch 18" fan . The factory shroud won't work because of the engine offset . I am just getting this car out after a long restoration . I have just 10 miles on it other than running in my driveway . I have NOT changed the radiator cap or the clutch fan . I would like to enjoy this car before I expire . Thanks again , Tom
 
383Scampman said:
What's the difference between a Hayden #2765 and a #2947 ?
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Exactly I don’t know but it would be how long they are off the engine. This would determine where the fan itself will sit in the shroud. You would want the fan blades no deeper in the shroud by approximately 3/4 of the blade and no shallower than 1/2 the blade. More or less reduces the effectiveness of the fan.
 
F.Y.I. guys . A Haden #2765 is standard duty fan clutch and #2947 is their heavy duty fan clutch . I'm going to flush out the block , again . Get a new 16# rad cap and a #2947 clutch . I installed a high flow water pump along with a high flow 160d thermostat yesterday before I purchase a new radiator . I'll keep you posted , thanks again , Tom
 
383Scampman said:
...I drained the coolant out yesterday and it was loaded with rust . Tom
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all these suggestions can help, but only if the water is flowing in the motor. at the least, you need to flush as much crap out of the motor as you can. the back flushing kits work sometimes...but, the only good way to do this is pull the motor, knock out all the freeze plugs and flush and scrape all the crap out. PIA i know, but worth it. p.s. heater core is going to be suspect after all this time too

good luck
 
I used a Dodge Dakota radiator cap. Just a few more pounds! LOL
 
383Scampman said:
What's the difference between a Hayden #2765 and a #2947 ?
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One is 3 1/4" long, the other is 2 5/8 " long. I have both for sale , phone pics upon request. 2947 id virtually brand new, comes w/ the appropriate studs for mounting to the water pump.
 
If you hold a wadded up small shop rag against the engine side of the fan blades and you can stop it with the engine idling it's garbage.
(10 second fan clutch test, and been doing it this way for decades)

Now all the newbie mechanics can freak out, and if this scares you don't F'n do it and just go buy a new clutch.
 
Ordered a #2947 fan clutch and lower radiator hose from rockauto.com . Should be here Monday . I'll let you know .
 
clutch fans slip and turn at as low as 80% of crank speed at idle and lo speeds...exactly where most engines need extra air.Try a proper mechanical fan but i'm betting it needs a 3 row or the newer 1 1/4" dual tube style rad.
 
Thanks ir3333 . that's my next move . I tired of throwing parts at the thing . I want to drive it . So far , I've gone 12 miles since completion .
 
ir3333 said:
clutch fans slip and turn at as low as 80% of crank speed at idle and lo speeds...exactly where most engines need extra air.Try a proper mechanical fan but i'm betting it needs a 3 row or the newer 1 1/4" dual tube style rad.
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A directly mounted fan to the W/P?
HP thief in a big way.
Better radiator? Probably so with the B.B.
 
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