Heater Core Orientation
 

Does anyone know what will happen if I mount my heater core so the air blows through it vertically?

I assume the the inlet/outlets on a 2 pass HC are at the top to facilitate air bleeding...

I would really like to place one sideways (rotated 90 degrees) or even better lying flat with the fans blowing up through them.

Any thoughts would be welcome. I've searching a billion forums and I haven't seen any mention of this.

I've got a similar problem.

I'm mounting my core vertically, and I need to decide if I should mount it with the tubes at the top, or the bottom.

If I mount the tubes at the top, a bleed won't take all the coolant out.

If I mount the tubes at the bottom, then the core is going to act as an airtrap.

So I have an option to put (weld) a small tap in the bottom tank, but I don't know which way to go, still: do I use the small tap to drain the core, or to let air out? Seems to me like it wouldn't let any air out, but would more than likely allow me to drain the coolant.


As for a horizontal mount, seeing that the core would be at the top of your rig, it's very likely that it's going to trap air. Knowing that, you'd have to pre-fill the rig, with the core dangling down, then set it back up.

Mines upside down. With a good res + pump the force of the water eventually dissolves and bleeds all the air out. Takes a week but works fine IME.