7 lb radiator cap Question?

[Groover]

So the old timer who just re-cored my original Comet 2 core radiator suggested I run a 7 lb cap instead of the 13 lbs I am currently running.

I've had two NAPA radiators pop a seam on the top tank. He says he only runs 7 lbs and runs them on all his cars. Makes the radiator last longer, and no issues as long as your engine isn't overheating.

What do you think? Any reason not to run a 7 lb cap?

[comethead]

I run a 13lb cap also.
I've heard of people going to a higher pressure cap, but not a lower. Seems like it would allow pressure release or boil-over way too early (especially ideling on a hot day or, say, climbing a hill). Anyhow if it works why not?

On the same subject, where are the NAPA radiators made? If they can't stand up to 13lb system pressure something's gotta be wrong!

Joe

[CALIFORNIA CALIENTE]

The highest pressure cap that you cooling system will handle without breaking parts is the best.The higher the pounds of the cap equals better cooling,I ALWAYS ran a 13 to 16 pound cap on the street!!! ROY.

[SASSY]

13 for me too, the shop I delt with said a 7 was enough,,not they don't trust their own work. Put the 13 on the car in 07 haven't had a problem.
Little copper rad, many miles including pulling our camper lots.

[bmmaurer]

Blowing seams with 13 lb cap 'cause the rads from NAPA are Crap.

GO aluminum.

Comet Bruce

[gmsnowball]

Bruce, let's see some pictures of your build. Mine is finished save the exhaust and a small tranny problem that should be ironed out in a day or two. It's over 100 degrees here so I'm taking it easy for the next few days.

[Comechero65]

I have never run anything but a 13# cap and never had a problem. I think the standard cap on a ford has always been 13# but I could be wrong. Seems like a poor quality rad if 7# is all it can handle. I think I would find another source for my rad.
Ron