Ross,

I had about a 10 degree drop across the radiator from top to bottom before installing the pusher fan. I have not measured it since so let me get a new measurement for you for before and after and I will report back.

Thanks

I normally have the shroud installed. I only removed it to do the test.

Since then I have installed a pusher fan which operates on 6 volts and is controlled by a user installed toggle switch under the dash board.

This helps a lot.

But the bigger point is that regardless of pusher fans and flex fans, the car should cool normally if restored to 1949 specifications, which I have done for the most part.

I still believe that the larger radiator is now having to be compensated for by pushing more air through it. And if the radiator shop had used the right core with the correct fins per inch and number of columns, I would not have to be doing all this jury rigging.

I hope to have more to come in the future on this.

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That is a good idea. I was thinking of a flex fan. Where do you think I could get one (in black)?

With the fan in front of the radiator as shown in the picture, the radiator works very well (as expected) with more air flowing through it.

I wanted to post an update on this situation:

As mentioned earlier, the original 419500 core is an inline Serpentine (fin type) with three rows and 11 FPI for a total of 102 - ?" tubes. The new core that was installed is a staggered continuous fin, four row with 8 FPI and a total of 150 - ? inch tubes (for 50% more tubes)

The tubes in the new core have a .118 belly vs the original 419500 which has .085 belly. Thus the core supplier said that I now have more volume (capacity).

I got an opinion from another radiator shop who does Packard work for one of the big Packard parts suppliers. They said that they believe that the key to cooling my car is not in the capacity of the core. It is in the fin distribution. They said that with serpentine fin patterns, the fin contacts the tube with a wider surface area. The heat transfers to the fin more effectively than a flat fin which contacts only a small area. When switching from serpentine to flat fin they said that we need to account for that. As a result they usually double capacity and max out fin count at 12 FPI (if they change to flat fin). They said that the new core I have has increased capacity, but has been decreased in fin count. They believe that this is what is hurting my cooling.

Many others have told me that they have never seen a bigger radiator cause problems. But my thought is what about if the fin count changes (fewer) and goes from serpentine to flat?

I have talked to a lot of other "experts" over the last few months. Many of them say that I need to supply more air through the radiator at idle to get the radiator to cool better at idle.

But I am starting to wonder if we have caused a mild conflict here?

Could it be that by going to the bigger radiator, we are now also forcing the situation to be resolved by needing more air to now blow through it? (need for higher CFM)

Could it be that the original fan with the original core was well matched and cooled as originally designed in 1949 with the higher fins per inch at a lower CFM? (with the stock fan)

And now that we have a larger radiator with more rows and lower fins per inch, we are forcing the need for more air (need for higher CFM)?

And the so called experts are basically right that we need more air but I am wondering if we basically forced the need for more air by going larger when we did not have to?

Remember that the original core was clogged and the radiator shop said that they checked the "manuals" and said I had the wrong core in the car and then sold me the larger replacement core. After much work and time, I realized that the original core (419500) was what was in there all along and was the right size. The call for bigger core was not correct on the part of the shop.

At this point, the only way that I see to resolve this is to go to a pusher fan as a temporary fix or go back to the original Packard 419500 core. The latter is more expensive but in order to keep the car original, I may have to do it.

There will be more to come on this post but I wanted to get this updated since I probably won't get time to resolve it until wintertime. In the meantime, I am going to a 6 volt pusher fan to get me through the rest of the warm weather

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Hi Jim,

No worries. I appreciate your help. Based on the drawing that I bought from the Studebaker/Packard museum, I believe the 3 row core is the correct one for the 419500 core.

Thanks again

Here is an update on my post.

I was able to get the drawing for the original 419500 core from the Studebaker/Packard museum.

It turns out that the 419500 core is an inline Serpentine (fin type) with three rows and 11 FPI for a total of 102 - ?" tubes. The new core that the radiator shop used is a staggered continuous fin, four row with 8 FPI and a total of 150 - ? inch tubes (for 50% more tubes)

The tubes in the new core have a .118 belly vs the original 419500 which has .085 belly. Thus the core manufacturer says I now have more volume (capacity).

I got an opinion from another radiator shop who specialize in radiators for older cars and they said that they believe that the key to cooling my car is not in the capacity of the core. It is in the fin distribution. With serpentine fin patterns, the fin contacts the tube with a wider surface area. The heat transfers to the fin more effectively than a flat fin which contacts only a small area. When switching from serpentine to flat fin we need to account for that. As a result they usually double capacity and max out fin count at 12 FPI (if they change flat fin). The current core I have has increased capacity, but has decreased in fin count. They believe that this is what is hurting my cooling.

There is more to come on this but I wanted to at least document where we are to date.

I was able to purchase the drawing of the original radiator 419500 from the Studebaker/Packard museum and I am having it compared to the replacement radiator that was installed in my car to see what the exact differences are. In this way, I can make sure my new radiator is close to what the original was.

Additionally, Ernie V was correct about the exhaust system. I had the muffler removed from the car and found out that it is not a straight through muffler but had offset chambers inside.

Once we replaced it with a straight through muffler, we picked up about 10 degrees in cooling performance. Thank you Ernie!

Interestingly enough, I asked the supplier of the core about the tubes used in my project and he responded as follows:

We do stock both dimpled and smooth tubes but to my knowledge dimples tubes were primary used on some larger truck applications in the 80's and 90's. Smooth tubes were used in the core provided to you

You are right. The "factory design" should be sufficient. So in my case, the radiator size was increased and as a result, the flow rate inside of the radiator went down. As the flow rate goes down, the fluid flow changes from turbulent flow to laminar flow. And we know that turbulent flow is better for thermal transfer. More heat is removed in turbulent flow than in laminar flow.

This situation is exacerbated at idle when the fluid flow is the slowest.

I am trying to get back to the factory design which is a thinner radiator with fewer columns so that I can get the flow rate up at idle.

In my case, engine has been rebuilt including new water distribution tube and new water pump. I have scanned the engine front to back.