Pulley Diameters

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Put almost 75 miles on the car this morning. A mix of mostly freeway & some surface street driving over a period of 2 1/2 hours. Temps never got above 205* & predominantly stayed between 195-200* :)

AC was on the entire drive & plenty cold!!

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what was the recipe that worked for you?

5 3/4" water pump pulley

7 1/4" crank pulley

Those were the only changes made to the cooling system. Lots of time & work to line everything up, but worth it!

I'm in business again :D WooHoo
 
Problem solved! I have a feeling your fix will help many here with the same issues. Great job there!
 
Problem solved! I have a feeling your fix will help many here with the same issues. Great job there!

Thanks Mike. This has been a thorn for several years, but I just dealt with it. Turn AC off until the car cools down....ugh :BangHead:

I don't remember reading much info about pulley diameters in the Heating & Cooling forum, but my gorgeous billet pulleys turned out to be the source of a perplexing problem. I'm not one to just throw $$ at my car & very well may have been able to fix it with a new radiator, but I wanted to try this 1st. 2 belts, $20 & some sweat equity. Done :D

Hoping another member or 2 may benefit from my solution.....:)
 
5 3/4" water pump pulley

7 1/4" crank pulley

Those were the only changes made to the cooling system. Lots of time & work to line everything up, but worth it!

I'm in business again :D WooHoo


I keep saying it's all about the FLOW. You can't drive the pump at crank speed, or worse, slower.

When I was in HS, I had the only MoPar. The Chevys were the worst. Almost every one of them had a 1:1 water pump drive. The simple fix was to find pulleys and speed up the pump. What I learned in the summer of 1980 I've never forgotten. Flow is the number 1 killer of cooling systems.
 
took me a long time to determine the March pulleys were causing me problems and hated to take them off but didn't like seeing it get to 240 either. The pulley change and Contour fan setup fixed mine. Glad to hear you got it!
 
took me a long time to determine the March pulleys were causing me problems and hated to take them off but didn't like seeing it get to 240 either. The pulley change and Contour fan setup fixed mine. Glad to hear you got it!

Thanks Joe!! Your early posts in this thread helped a bunch--Most appreciated too :thumbsup:

I know that sometimes the smallest change can make the biggest difference without just throwing
parts & $$ at it :)
 
Nice work C!

Now why in the damn heck doesn't the aftermarket make billet pulleys the same as factory? Why do they change the sizes?
 
Now why in the damn heck doesn't the aftermarket make billet pulleys the same as factory? Why do they change the sizes?

I think the billet pulleys are designed for maximum performance, not maximum cooling. Most people can sacrifice temps for better horsepower. I can't do that because of where I live....

Thanks :)
 
I have to say that I am surprised that overdriving the pump would have made that much difference.
This was a great experiment and a great learning excersize!
 
I had asked previously, where can I purchase the pulleys that you used?
Also, do you believe the solution was due to speeding up the water pump or turning the fan at a faster rate? I ask because I am using an electric fan set up, so I am trying to determine if speeding up the water pump will help me or not.
 
I had asked previously, where can I purchase the pulleys that you used?
Also, do you believe the solution was due to speeding up the water pump or turning the fan at a faster rate? I ask because I am using an electric fan set up, so I am trying to determine if speeding up the water pump will help me or not.


Water pump speed it critical. Once you are moving 15-20 MPH the fan is actually in the way. It's all about the FLOW.
 
I have to say that I am surprised that overdriving the pump would have made that much difference.

Me TOO!! But it does make sense...

This was a great experiment and a great learning excersize!

There was enough improvement with the 1st change--water pump pulley only that it made sense to overdrive the water pump & fan additionally with the 2nd crank pulley change.

Thanks for your input. :)
 
I had asked previously, where can I purchase the pulleys that you used?

Sorry I missed your previous post. Pulley info below...

Please tell us what pulleys to look for!!!

Both pulleys used were original Mopar pulleys.

The 5 3/4" water pump pulley is from a 64 273 V-8 car with AC.

The 7 1/4" crank pulley was original to my 340 non AC car as far as I remember.
 
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