radiator cap pressure

[coolair]

Any idea what pressure radiator cap you should run on gas engines? I have the Ford 460s and have looked through the service manuals i have and best i can find is its either a 7LB or 13LB

[mike ohlstein]

Go with the 13, I would think.....

[Stephan]

I believe my Crusader 454s are a 7 lb. cap.
I have the Lenco heat exchangers.
Stephan

[mike ohlstein]

Oh boy.... There goes my car knowledge, spilling into places it doesn't belong.......

[coolair]

you got me really wondering now. I was thinking 13 was OK too.

[Tooeez]

I had 13lb caps on my 350's, and was loosing some coolant. I borrowed a pressure tester from the auto supply store, and found I had a small leak where the return hose enters the exchanger. The clamp wasn't all that loose, so on a whim I tested the caps. One opened at 22 lbs, and the other at 19 lbs. I replaced them with 7lb caps, which when I tested them opened right around 12 lbs.

[Stephan]

Yep. Just double checked and my caps are stamped 7 lbs.
Best,
Stephan