waterzap

So this weekend rebuilt the carb on my 67 Toronado. Car definitely pulls better now. However now a new problem has cropped up. The intake manifold started to weep . Its in the front, nothing comes out of the bolt holes. This only started to happen when I started to push the engine a bit. It runs fine, but now the leaking? Also, the upper hose did look a bit bloated last night after I did a test run. I have a new radiator cap, 16 psi I believe, new pcv valve, and I can see some fumes coming out of the breather on the other side sometimes.
I measured the temp on the upper hose with my infrared thermometer, and it was around 190 or so.
Before I did the carb, I didn’t have this problem. The car probably didn’t run well enough.

waterzap

Might want to add that the previous owner added an overflow tank. Will just disconnect that next time I bring the car out. See if it dumps coolant.

oldcutlass

I don't think the 16psi cap is compatible with the overflow tank.

waterzap

So get rid of the overflow tank? Do you have an overflow tank?

oldcutlass

No, I'd keep it, I was planning on getting one in the future, maybe... You can get a lower pressure cap that's made for an overflow tank. It will allow coolant in and out of your radiator as it heats up and cools. With the 16# one your going to see the upper radiator hose swell when the car is at temp.

waterzap

Thats pretty much what is happening. Once again...if change something...something else has to be changed too.

waterzap

Very interesting. Looking at Stant 10330, which is specified for my Toronado. Non vented vs 10331, which is vented, and specified for other cars with an overflow....
Use the "vented" cap if you have an overflow tank, "non-vented" if you don't

oldcutlass

You want a vented cap for a closed system. This will allow the fluid to go in and out. I would run about a 6-8# cap and that's good till almost 260 degrees. Then just make sure the hose to the overflow can draw the coolant from the tank.