Radiator Cap
 

1960, looks to be original radiator but appears to have been re-cored and using normal 7# cap. Just wondering if anyone has experimented using I believe what was the next step up in 1961 to a 13# cap. It seems like a big jump and I'm not sure if there is a cap between 7 and 13 #'s that would fit.

After flushing radiator and putting in a hi-flow thermostat most of over heating problems have gone away on hot days (hi 80's lo 90's) but when engine turned off overflow tube releases coolant to the ground (as it should).

Trying not to use recovery tank or purchase new radiator. Is a 13# cap too big a leap or is there something out there in between that might work or do I just need to bite the bullet and get a new aluminum radiator ?

Thanks, Paul

I run a 13# cap on my '61 but I have an expansion tank....car runs cool with no "puking" of coolant..but I do have an aluminum radiator.

try the cap.. a higher pressure cap just increases the boiling temperature of the coolant and minimizes the puking. just remember, the radiator will puke til the coolant reached equilibium with the expansion/contraction of the fluid. don't just keep adding as it will keep overflowing.

after a puking session, when the it's cool enough (but not sitting-overnight-cool) remove the cap and see where the coolant level is. then try it again the next morning; should be lower (but not down to the level of the radiator core).

keep checking over several days and see if the levels remain constant... if so, you're OK
Bill

I used to use a 15# and now I'm using a 7#.I use an expansion tank and since installing a new DeWitts radiator a few years ago never have any puking.

The curved filler neck on 55-60 radiators does not allow you to check the level and that's why this problem occurs. Since you can't see how much is in there, many tend to add more, and when it pushing it out, they add more.

How old is your heater core? Will an almost doubling of cooling system pressure risk the integrity of your heater core?

Exactly. I've never run anything but 7 PSI caps. If your cooling system is in good shape, you won't have a problem. There's no need to add stress and increase the leak possibility by increasing the pressure. Going from a 7 lb. to a 15 lb. cap only raises the boiling point 17 degrees.

Jim

:iagree: Stay with the 7#...

No reason these systems shouldn't handle 13# of pressure or you obviously have other problems...here is an NOS cap you can pick up quickly for a test if you don't mind spending a LITTLE extra money for an original:
http://cgi.ebay.com/ebaymotors/1959-Corvette-FI-Fuel-Injection-New-AC-RC6-Radiator-Cap-?cmd=ViewItem&item=310119092681#vi-content

as Frank says, if your system is in good shape, the 13-15# cap will do no harm.

i just looked at where you live and i see it is up towards the Georgia mountains. if you do any driving into the appalachians, and it gets as hot as it did up there this summer, then a higher pressure cap will allow a bit more engine temperature while climbing some of the steep grades.

my .02..
Bill

On my 59, I was running a 13# for years. Didn't know any better. Last year, blew a few holes in a 35 year old radiator. Actually found a guy who re-soldered the old original radiator ( the old ones apparently don't have "tubes", it's the small little fins that carry the coolant and are very difficult to solder). Went back to a 7# cap. No problems yet.
I also installed a 61 expansion tank. Was tired of having coolant all over the floor.