FIA Expansion Tank question, regarding overflow

[1795]

That helps clarify things a little better, in the first post it sounded like you were going to run the expansion tank dry. Your expansion tank sits lower than mine, mine is the upper most piece of the cooling system and sits on top of the transverse leaf springs tower. If you plumb the hose to the catch can into the bottom of the can it could get sucked back into the Harrison tank, if you plumb the hose into the top of the catch can it will not suck anything back into the Harrison tank unless the catch can gets filled to the level of the hose entering it.

[Buddy Rawls]

My Harrison tank is the highest point as well. It has to be, if the halfway point of the Harrison is same height as the highest part of the cooling system (upper radiator hose). My guess is mine is mounted near same height as yours. The radiator cap is about 1” below that part of the hood.

You commented about, Expelling into top of catch can. That’s just it, if it does expell into the overflow/catch can, I do want it to recover it. Otherwise the level
of coolant in the system just dropped that amount, just like it did years ago. So you can plumb into the catch can so it can recover the expelled amount; but only that amount.

In these posts I feel I’ve answered my own question. The catch can (recovery, in
my case), must not filled with any additional antifreeze.

[1795]

Yes, Buddy, you are correct in that the catch can is there only to prevent excess fluid from leaking onto the road. The Harrison tank is for holding normal expansion of fluids. It is interesting how differently the expansion tanks can be plumbed. Mine is way different than yours.



Is your concern theoretical (this may happen), or have you had issues with the coolant in the Harrison tank overfilling it and dropping it on the road? In all the time that I have raced mine I have only had a small amount of water get deposited in the catch can.

Good luck.

Jim

[Buddy Rawls]

Actually, mine will be plumbed exactly like yours. Lower inlet Of the expansion tank is plumbed to the block. In my case, one of the water pump heater hose outlets.
The upper vent port (not the radiator cap pressure release) is plumbed to a high spot in the cooling system so hot air can be exchanged and equalized between the
expansion tank and the cooling system. In my case, I’ll tee in to the upper radiator hose, yours goes to the top tank. And the radiator cap pressure release port goes to the catch can.

No, I Do not have problems currently. Just adding the Harrison Tank
to Match the authentic race cars (FIA, USRRC, etc). I’m just trying to cover everything. I’ll finish it this week schedule permitting.

Is yours an original? or a modern CSX? either way, nice. Id love to do some webers. For now Ill have to stay with my C9OX Ford Intake and 650 DP.