Radiator flow direction
 

Hello all.
Any radiator experts out there? In my race car (The lotus 7 replica) I am contemplating changing the direction of the flow of coolant through the radiator.
Is there any problem with this? Seems like It should not matter which direction it flows to me but.....does it?

Yes it will the water pump circulates the coolant through the engine ,.And as it comes in to the top of the radiator , and as it falls to the bottom then it gets cooled down by the fan or fans if you have 2 of them .

Hmmmm, also seems like sometimes the inlet and outlet are not the same sizes...outlet smaller for coolant shrunken by cooling...?

If two different sizes are used, there needs to be a larger hose on the suction side than the pressure side. Since the suction side may be under a negative pressure, a larger hose (less restriction) is needed for proper flow. As the coolant leaves the engine at a higher velocity, it doesn't need as large a return hose.

The more practical reason you can't suck coolant from the top of the radiator is, what happens if your coolant is half an inch low... You'll suck air and it won't work.

That makes sense.

Thanks!

Flowing backwards (i.e. from the bottom up) is also counter to natural convective flow through the system...coolant heats up and expands, becomes less dense, rises to the top of the engine. Then travels over to the radiator, cools, becomes more dense, falls to the bottom of the radiator. The water pump is set up to assist this natural flow.

Yes. Thanks Jaybob!

Is this a crossflow or downflow radiator?

The core is indiffernt to flow direction, but:

1 The inlet should be placed higher than the outlet, to get the benefit of convection.

2 On most radiators, the outlet will be LARGER than the inlet in order to raise pressure at the pump. This helps reduce pump cavitation.

It appears to be a downflow.

Were you thinking a complete reverse flow system?

I don't think so. I was thinking about it because the hoses cross under the engine and I'd like it better if they didn't.

How about relocating the inlet/outlet? They should be in opposite corners, but that still leaves two choices.

Oh that's not necessary. I'll just live with it as it is.

Thanks for the thoughts!

(Also, its an all aluminum radiator so relocating the nipples would be tricky.;))

Assuming you could take care of the other items mentioned here (flow direction, cooling of water and density etc...)

.... I think it is more important that you do not send the cooled water into the head.

Not that that is what you stated, but typically, that is how these items line up in a car.

Isn't that exactly where it goes?