289 Coolant flow direction?

[Cdaniel]

Can anyone tell me which direction the coolant flows through the heater core on a 66 289? Intake manifold to pump? or opposite?

 

[geegee]

Originates (pushes) at the water pump, flows through the heater core, back to the intake manifold. Note: at the manifold the heater inlet sits next to the engine outlet. Movement of water through the manifold and into the radiator causes a small vaccuum at the heater return line (it sucks)! Who says you'll NEVER use HS Physics?

 

[D.Hearne]

It runs just the opposite, from the intake thru the heater core then back to the pump, not that it really matters, the core will function with the coolant flowing in either direction.

 

[Cdaniel]

It runs just the opposite, from the intake thru the heater core then back to the pump, not that it really matters, the core will function with the coolant flowing in either direction.

Ah ha! A controversy now!. Apparently it does matter, at least that's what the guys a Classic Auto Air claim. I'm not inclined to believe that having the water control valve on one side or the other matters when it comes to the fact that my vent temp is 60 degrees. But I thought I'd try it. I'm leaning to the notion that their valve sucks and doesn't really shut flow off completly. But that's just my ignorant opinion.

 

[Ronstang]

No controversy, D. Hearne is correct that the coolant flows from the intake through the heater core and back into the pump.

 

[D.Hearne]

Ah ha! A controversy now!. Apparently it does matter, at least that's what the guys a Classic Auto Air claim. I'm not inclined to believe that having the water control valve on one side or the other matters when it comes to the fact that my vent temp is 60 degrees. But I thought I'd try it. I'm leaning to the notion that their valve sucks and doesn't really shut flow off completly. But that's just my ignorant opinion.

It may matter in the case of a shut off valve, but if you put it in either hose, and run the motor long enough, the coolant in the heater will eventually reach the same temp as the rest of the cooling system. That's one reason why I advocate using a shut off in both heater hoses. The other reason is , if your heater core springs a leak, you can isolate it from the rest of the system and continue on your merry way and fix the leak later. And heater cores DO spring leaks, seen it happen TOO many times. Sometimes happens when the engine is rev'd up higher than normal, the pressure goes up higher than the core will stand.

 

[2nd Mustang]

And heater cores DO spring leaks, seen it happen TOO many times.

Oh please don't remind me. As easy as it is compared to new cars, it still was a PITA, especially when you're old like me! (End of hi-jack)

 

[WORTH]

Ah ha! A controversy now!. Apparently it does matter, at least that's what the guys a Classic Auto Air claim. I'm not inclined to believe that having the water control valve on one side or the other matters when it comes to the fact that my vent temp is 60 degrees. But I thought I'd try it. I'm leaning to the notion that their valve sucks and doesn't really shut flow off completly. But that's just my ignorant opinion.

If you think the valve is bleeding by, buy and install an "H" pipe bypass between the engine and the valve, the water will flow the path of least resistance and wont flow threw the heater.