Correct pulleys for 440 w/AC

[Big_John]

Thing is, my car runs fine when it's in the 70's or low 80's. Once the temps hit 90 here and I've run the car for a while, my temp starts hitting 200-210 depending on how bad traffic is and how long i'm sitting.

First... I hate you. It's in the 30's here and it snowed yesterday.

Second, that temperature isn't all that bad. I have similar temperatures with the A/C running on hot days.

Have you tried a 160 degree thermostat? That won't limit the temperature if there's something wrong, but it does start cooling the engine a little earlier.

 

[70Tom]

The problem is not the diameter of the water pump pulley it is the offset. The non ac pulley is deeper than the ac moving the belt back to the rear most groove. The ac and non ac water pumps are essentially interchangeable (won't get into that discussion).

So you'd need the pulley that is more of a top hat than a beret to remove the ac compressor.


Alan

Yes, understood on the offset.

So a smaller pulley will not spin the pump faster?

 

[70Tom]

First... I hate you. It's in the 30's here and it snowed yesterday.

Second, that temperature isn't all that bad. I have similar temperatures with the A/C running on hot days.

Have you tried a 160 degree thermostat? That won't limit the temperature if there's something wrong, but it does start cooling the engine a little earlier.

Haha. I'm sorry John. I lived in that many years and am very happy I no longer have to deal with it.

Yeah, I know it's not horrible, but I have a feeling if I was really stuck in bad traffic, it would keep climbing and eventually overheat. Plus, once I get the A/C working, I know it's going to heat up even more. Plus the temps here are going to heat up even more come summer, so I really need to get this cooling thing done correctly.

I have not changed the thermostat yet. I was trying to troubleshoot this "correctly" (if there's is such a thing). Was going to go power flush, then thermostat, then water pump, then radiator recore. However, I started reading about the pulley issue and thought that would solve the problem.

 

[70Tom]

Also, it really seems like I could just get an 8-blade water pump and stop worrying about this pulley stuff. I could just put the 6-blade back in when I install the A/C. If so, where's the best place to get one? I saw AutoZone appears to have an 8-blade.

 

[Big_John]

Also, it really seems like I could just get an 8-blade water pump and stop worrying about this pulley stuff. I could just put the 6-blade back in when I install the A/C. If so, where's the best place to get one? I saw AutoZone appears to have an 8-blade.

Here's some reading for you about different pumps. Someone did some flow testing on different impeller combinations.

An Error Has Occurred!

Starts getting good about halfway down the page.

 

[Big_John]

I have no idea why it says "error". The link is still good.

 

[70Tom]

Here's some reading for you about different pumps. Someone did some flow testing on different impeller combinations.

An Error Has Occurred!

Starts getting good about halfway down the page.

Interesting test. Like the one guy says before the tests began, I think I'm sticking with the stock housing and I'm going to buy this and get a 160 thermostat. It's not bad in price in case it doesn't cool well.

http://www.autozone.com/cooling-hea...-pump/duralast-new-water-pump/61161_381122_0/

 

[70Tom]

Here's some reading for you about different pumps. Someone did some flow testing on different impeller combinations.

An Error Has Occurred!

Starts getting good about halfway down the page.

John, here's a question for you. If I go with the new 8-blade pump, would you still go with a 160 thermostat, or is that too cool?

 

[Big_John]

John, here's a question for you. If I go with the new 8-blade pump, would you still go with a 160 thermostat, or is that too cool?

I had to replace my water pump this summer. I wiggled the fan and it was obvious the bearings were on the way out. It was the week before Carlisle, so I didn't have a lot of choice. There no longer was an A/C option listed for my car. They have one pump and that's it. An 8 blade pump replaced my 6 blade A/C pump.

There was no difference in how the car cools. None. It didn't stay any cooler and it didn't get any hotter.

So... I probably wouldn't change the pump based on my experience.

To answer your question though, I'd change the thermosat either way you go.

 

[MrMoparCHP]

No combination of different pumps & pulleys is going to fix your problem. You have a 40 year old radiator 40 year old engine.

As for the difference in water pumps, the impeller on the 8 blade is smaller in diameter than the 6 blade. So just having more blades doesn't mean it moves more water.

As far as I know there are only two different pulleys, the ac and non ac pulley, each of those have different diameter.

The engineering behind all this is probably above all our pay grades.


Alan

 

[70Tom]

I had to replace my water pump this summer. I wiggled the fan and it was obvious the bearings were on the way out. It was the week before Carlisle, so I didn't have a lot of choice. There no longer was an A/C option listed for my car. They have one pump and that's it. An 8 blade pump replaced my 6 blade A/C pump.

There was no difference in how the car cools. None. It didn't stay any cooler and it didn't get any hotter.

So... I probably wouldn't change the pump based on my experience.

To answer your question though, I'd change the thermosat either way you go.

Wow, that's pretty surprising there was no change based on all the stuff people post. So it kind of sounds like I'm better off changing the thermostat and doing a power flush.

 

[Samplingman]

Not sure if this will help, but here is a stock setup from my 70 300:

You should also consider an over-flow bottle. I'm going to upgrade to an actual overflow, but you get the idea:

 

[70Tom]

No combination of different pumps & pulleys is going to fix your problem. You have a 40 year old radiator 40 year old engine.

As for the difference in water pumps, the impeller on the 8 blade is smaller in diameter than the 6 blade. So just having more blades doesn't mean it moves more water.

As far as I know there are only two different pulleys, the ac and non ac pulley, each of those have different diameter.

The engineering behind all this is probably above all our pay grades.


Alan

haha. Yes, it probably is. Hence why I was considering just going to an 8 blade pump with the non-AC pulley for now. However, John said he saw zero difference whatsoever, so there doesn't seem to be much point. Right now, it seems like my best option is get a 160 degree thermostat (looking at a 160 High Flow Milodon) and then get the system power flushed to see if there's any major crud blocking passageways in the block and/or radiator. If neither of those 2 things solve the problem, I'm left with getting the radiator re-cored.

 

[70Tom]

Not sure if this will help, but here is a stock setup from my 70 300:
You should also consider an over-flow bottle. I'm going to upgrade to an actual overflow, but you get the idea:

Thanks for the pics.

 

[commando1]

The engineering behind all this is probably above all our pay grades.

Ah. A sane voice from the crowd cries out.
Thank you.

 

[70Tom]

Ah. A sane voice from the crowd cries out.
Thank you.

Where's a MOPAR engineer from the 60's when you need one.

 

[MrMoparCHP]

Keep in mind the thermostat does NOT impact the operating temperature just the point that it opens, if your engine is running at 200 it will run at 200 regardless of what thermostat you have.


Alan

 

[Big_John]

Keep in mind the thermostat does NOT impact the operating temperature just the point that it opens, if your engine is running at 200 it will run at 200 regardless of what thermostat you have.


Alan

Yes and no.

If the engine runs at 200 no matter what, that's true. It will run run at 200 no matter what t-stat is in the engine. A cooler running engine will be more dependent on t-stat opening temperature.

To give a specific example, my 70 300 had a 195 degree t-stat in the car when I bought it. Living up in the hills, on a hot summer day, the engine would ping hard driving up the hill to my house. With the only change being a 160 degree T-stat, average operating temps dropped about 10-15 degrees and the pinging stopped. Chances are good that changing to a 180 degree t-stat would have the same result, but a lot of past experience has shown me that the 160 is my preference.

The t-stat really is for letting the engine warm to operating temperature, but it will influence the final operating temperature in some cars. I've had similar results in other cars. When I was using c-body Chryslers as tow cars back in the 70's, changing to a 160 degree t-stat was pretty much one of the first things I did. It brought the temp down just a little, but enough to make it worthwhile, especially when towing.

I haven't tried the "high flow" t-stats though. I've thought about it for my 300 just to see if that might bring the temp down a little more at idle.

 

[pomonamissel]

here is a couple of my a/c pulley set up .

 

[70Tom]

Thanks guys. 160 high flow Milodon thermostat is ordered. I'll let you know how it goes once I get and install it.