Radiator Cap
 

I just installed a Fluidyne Radiator in my 89 GT and was wondering what cap to put on it. My stock radiator had a 16 lb cap and I believe that is too much for an aluminum setup, am I right? If so, what cap should i run? ~Brian

I know the least amount recommended is 13 pounds and the max is 18 lbs.

Try the 13 and see what temp reading you get. I still think 16# would still be safe though.

I agree

nice avatar 82 GT, love it :D

You like that? Thanks!

Looks like I'll be picking up a 13 lb cap in the morning. This aluminum piece should cool 10x better than stock now! ~Brian

NOOOOO!!!!!

Get a 16, MINIMUM!!!

Aluminum can't handle it??? Hmmm. We use a 24 pound cap in the Sprint car, and we ran a 32 pound cap in the Taurus when I worked for Bill Elliott.

Unless it's made from foil, your aluminum radiator will be fine. If you have concerns about the rest of your system, I suggest you have it pressure tested first.

Take care,
~Chris

Pkrwud , I thought a 16# cap would suffice but it didn't seem like he would believe the rest of us if we told him that.
13# is the min. though, according to the Haynes manual.

Well, after all, 82 GT, you tell me to try a 13 lbs one and go from there, but I would have believed me if you said use my 16 lbs. one. I forget where I read it, but on some site I read that you couldn't run as much pressure through aluminum as the brass ones. :confused: Oh well, I'll put that 16 lbs on there, thanks to everyone, btw, that is a nice avatar 82 GT:D ~Brian

PKRWUD

I see I still have a LOT to learn. I got a Fluidyne radiator about a month and a half ago. I used the stock cap. Is that ok? What's it's rating?

- on a 94 GT

Radiator caps suck, in general, and really should be replaced every year as preventative maintenance, IMO. They cost less than $10, yet a bad one can and will cause blown head gaskets. I would never use a cap rated less than 16 pounds on an engine with any mods, because they will run hotter. The more pressure the cap can take, the better it will control the system. To a point. I install 18 pounders on the cars I work on, provided they can hold 20 pounds for 10 minutes on my tester.

Brass heater cores will almost always fail before an aluminum radiator will, so pressure checking the system really is important.

Also, keep in mind that the single item that is responsible for the accuracy of the cap is a metal spring, and the quickest way to vary the accuracy of anything metal is by repeated hot/cold cycles. This is why t-stats should be replaced more often, too, but nothing is as easy to replace as a radiator cap.

:)

Take care,
~Chris