Packard Forum Index » Post-War (1946-54)

Plastic = poor heat xfer????
Maybe i don't understand the purpose of the DISTRIBUTION tube. Is it not for the sole purpose to DISTRIBUTE coolant and is located INSIDE of the engine??? Ergo it is NOT a radiator nor a heat sink and ergo any heat dissipation or absorbption properties of the tube itself are irrelevent.

Brass or copper or bronze or SS are poor conductors of heat. Or poor compared to steel or Al. NO???

Many common production cars over the last 10 years haave plastic radiators??? Or am i just hallucinating???

The tanks are plastic, but the core is aluminum these days.

Thermal Conductivity (higher is better conductor)

Carbon Steel 360
Cast Iron 310
316 SS 113
Al 5052 960
Naval Brass 810
Bronze 524 350

Copper-Beryllium alloy is used in tooling when you want really fast heat transfer

your point on distribution vs conductivity is well taken though. The lower modulus of , say, polyamide ("nylon")
would mean a thicker tube and less flow area.

I think header tanks are polyamide on modern cars, not the cooling surfaces themselves.

agree that steel is a terrible choice

I don't think one would need to be too concerned with heat transfer on a distribution tube. I would be more concerned with the corrosion or rust issues. While plastic might be optimum in that respect, I would think brass or quality stainless the better choice since plastic would need to be thicker & probably result in reduced flow. I could also foresee some non standard conditions where there is a chance plastic could actually melt inside a block and form a blob almost impossible to remove.

As far as a repro goes, that should be an easy do with brass or stainless once the dimensions were input into a CNC program to cut the holes and basic shape. Bending it up in a single piece and then rolling the seam might be an issue without some custom mandrels and equipment but if it were made in two pieces it could be bent on a simple sheet metal brake with brazing or welding at opposite corners or sides to make the tube shape.

...with brazing or welding at opposite corners to make the tube shape

I've repaired some using silver solder which has a melting point well above anything likely to be encountered. Pretty easy soldering brass.