tylerwerrin

hi guys,

I'm running a Moroso 63766 expansion tank:

Tank

Previously, I had been using a 99 chevy Malibu tank for my overflow & header tank but i swapped over to the Moroso because it was more compact and looked nicer.

Anyways, the Moroso tank has a 3/8 NPT bung on the side as well as a 1/4 hose barb on the neck. Right now I have the radiator over flow tube hooked into the 3/8 bung (which currently has a 90 degree hose barb fitting in place) and the 1/4 nipple from the neck is hooked into my coolant over flow tank.

I have read that some people just connect their radiator overflow tubes straight into the coolant over flow reservoir, and i wanted to make sure it's ok to do it the way I have it hooked up before i start driving around.

Thanks!

shoebox

All 4th gens f-body cars come from the factory like this. But, if you need a pressurized holding tank like the Malibu or B-bodies use, then that tank might not do.

tylerwerrin

My radiator doesn't have the pressurized radiator cap integrated into the radiator like on the camaros. My radiator has an overflow tube at the top of the radiator, which i run back into the pressurized tank. The pressurized tank has a small barb fitting at the neck which i've run a tube from to the unpressurized overflow tank.

i know this isn't how it's done from the factory, i'm just wondering if my setup will be OK and not cause any problems. It seems to mimic the b-body tank system, but I'm just nervous about cooling systems especially because the engine is in a rather big car; i had posted on the forum before checking to see if it's ok to use a pressurized header tank, and the answer was "i don't see why not". Has there been a new consensus formed on the issue?

shoebox

It's not clear to me if the Moroso tank can be pressurized or not. I assumed not, by its looks, but I don't know what kind of cap/venting system it has. Obviously, the cap has to be able to hold pressure or it wont' work.

tylerwerrin

The moroso takes a standard radiator cap, so that means its pressurized, correct? I am using a Stant 18lb cap with the lev-r-vent feature. Since the radiator has no provisions for a cap on it, this is my only option, other than adding a splice in the hoses and adding a remote filler neck. If the tank holds pressure, this setup should be OK, right?

for added clarity, the Malibu tank only holds 15lbs of pressure vs the camaro which needs 18psi -- i bought the 18lb cap for the moroso tank, and it fits and locks onto the neck as it should -- i'm just wondering if the rest of the setup will be OK.

shoebox

I'd say you are ok, then, if the tank is rated for 18 psi.