New Radiator

[Labrauer]

I purchased a new three core radiator for the 48 Plymouth coupe "230 engine" because the old original one the overflow tube broke at the neck and no one wants to work on or they say they won't work on the old honey coned ones. My question is the new radiator came with a 19# cap and I think the old cap is just a 4 or 5# cap. If I install with the new 19# cap will it make the car run hotter than the regular old cap? And of course the old cap won't fit the new radiator> 

Open for advice.

[Sniper]

It won't make it run any hotter, or colder than it did with the old radiator. 

[DJ194950]

Buy a new 4-7 lb. cap of the new style.

 

Easy and have done this 3 times now.

 

DJ

[Dave72dt]

No, it won't make it run hotter.  The thermostat still controls the temp.  It will allow the engine to run hotter before boiling the coolant.  The old heater core and/or other components may not like the higher pressure so a lower psi cap would be a good idea.

[Labrauer]

Thanks for the replies I will see if I can find a lower pressure cap that will fit the new radiator. 

[Young Ed]

Your 48 should have been a no pressure system. I think a small amount would be fine but I wouldn't use the supplied cap.

[Los_Control]

I think the biggest issue would be putting pressure to the heater core.

Should be able to find a 0 pressure radiator cap? I never have looked for one.

 

Thinking this will be my next project, install the new to me aluminum radiator. I may have same problem. I have to dig it out of the attic .... but it does have a cool custom cap.

So I do want to use it, I may try to gut it out or remove the spring that enables it to pressurize.

That would be my first plan .... if needed.

[harmony]

That's a sad commentary on the rad shops in your area.  What would scare them off about soldering that tube back in place?  I'm curious why not buy some solder and a fine tipped butane torch and do it yourself?  I had a small leak right around the neck on mine.  It took me longer to remove the rad and take it to them then it did for them to resolder it.  The only reason I didn't do it myself, is that I wanted them to test the entire tank and assess the overall condition of it.  They said it was fine, but if I ever wanted it restored one day they would remove the upper and lower tank and replace the honey combs.  But it would cost about 3 times as much as "modernizing it with new cores, but still using the same upper and lower tanks.