A-Body 440 cooling problem

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Duster Bud

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I guess I am going to keep you guys busy with questions....
The 440 4 speed engine that came in my Duster had an stock 8 blade steel fan. The problem is that the fan pully has 2 grooves and the only one getting the use has only got about a 23% wrap. It squeals like a stuck pig. I tried a clutch fan in it's place and seems to run hot. (26"X18" 3 core, stock)
So....if I go with an alum rad. Do I need the dual fan or single or should I try the ele on the old stock rad. Oh..almost forgot the car does have a complete AC system installed. (not charged yet). Do I need a pusher on it or just hook the rad fan switch to the AC control to bypass the thermostat in hot weather? How many CFM will cool a 440 street car in warm weather with AC.
Also...do you guys run the fan on a thermostat or on with the key?
Bud
 
Depending on how much HP you are making a clutch fan with a shroud using the stock big radiator like you have should cool the beast.

The basics are what you need to look at :

Verify the operating temperature using a mechanical or mercury thermometer. The electric guages are not accurate.

Are you using the correct factory designed pulleys for your engine application ?

Are you using a shroud ?

Are you using the correct water pump for the pulley set up ? This is extremely important. The impellers on AC pumps are smaller and are matched to a smaller water pump/fan pulley, If you feel you need more flow use a NON AC pump with the AC water pump pulley. The impellers on Non ac pumps are larger, and are matched to a larger pump pulley used in non AC applications.

Are you satisfied that your thermostat is working correctly ?

Are you using a coolant water mix ?

Are you running enough initial timing ? Retarded timing will cause excess heat.

If any of these are out whack then you may have issues.
 
I had a similar problem with my 383 A body with no shroud. A flex fan solved it and then some.
 
if you don't have a shroud, get one. it helps pull the air thru the rad instead of scavenging air from all over the engine bay. are you running a 180* HP stat? hi flow water pump? aluminum does not cool more than copper/brass. the rate of heat dissipation at 180* is higher in copper/brass than aluminum. they are just lighter, and have 1" tubes and claim to be better than stock rads(2 row). yes they can be better than STOCK, but a high effieciency core(3/8" on center tube to tube instead of 1/2") and a 3 row with a good clutch fan and shroud is better than stock. use a milodon/mr. gasket stat(they open with the flow of water, stant opens AGAINST the flow).
 
First things first. Find out why the belt is slipping, is the pump hard to turn? The single belt drive for the pump-fan is more than adequate however I've never used an 8 bladed fan only a 7 or 6, but this might have been installed at the factory because of the Air Cond. Also if you haven't got a slotted belt like the Gates gatorback then get one, they're more flexible around tight corners (like the alternator sheave) and tend to grip better and slip less. If the belt still slips trying to drive that big fan then use 2 belts for the 2 grooves but they have to be "exactly" the same length and as said before you need a shroud.

Terry
 
Anyone know where I can find a big block A body fan shroud? What about a full set of tan seat belts while I'm at it?
 
Thanks guys,
You all are a pretty sharp bunch...Very good advice...and I thank you.
The fan was pretty heavy and the belt (new notched) didn't wrap very much of the pulley. It started to squeel around 2000 rpm (guessing) and did it every shift. I am also guessing that the clutch fan I replaced it with may of been a bad one It has silicone leaking from the heat spring. I figured that a flex fan would do the same squeeling...maybe not. The shroud is another problem. My fan seems to be in the center of a 28 X 18 radiator. Most shrouds seem to be off set. I saw a steel truck shroud that looked pretty close ,but missed it. I'm not sure the builder used the right K-Frame for the 440 install. I saw some welding on the motor mounts that wasn't very good.
The timing is also an issue. I will be checking it this Wed at a friends shop ( don't have a total advance light) I may have it too retarded because any more advanced...it doesn't like to start...it bucks a few slow revs when warmed up, then kicks off. (new starter and new gell battery 800cca). (manual choke...never used) The vacuum advance is disconected..might of been re-weighted? This friend of a friend is a mopar drag racer...hope to learn new stuff there this Wed.
Thanks for the very helpfull suggestions and advice. Good stuff to think about. Thanks, Bud
 
A thing that a lot of people miss is the rubber strip that mounts on the hood to seal the top fo the core support. It forces all of the air that goes through the grille to go over the radiator, not over the top of the radiator. Every little bit helps.
 
You might try checking the spacer between the pulley and fan. How far is the fan from the radiator? Try to get it within 1-1.5 inches from the radiator. This will insure a good draw of air across the cooling fins. A shroud would help a lot, but finding an original big block A-body shroud would be near impossible,( and wouldn`t work with your existing radiator anyway) however you may be able to find a 340/ AC equipped car to salvage one from.
 
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