classic auto air install question

[whytry]

I have the side exit system, the heater core in/out run parallel to the firewall, but it does not say which one is in and which one is out. On the parts or in the instructions. Does anybody know how to tell which one is which? One is larger than the other, but I don't know which is which. Anybody have any ideas for me?

I am trying to get it installed and run the Water valve too, and that needs to be inline from the heater core. On a BBC intake I see 2 places where I can run the heater hoses. One is supposed to run from the intake to the water pump, but I am running an electric water pump, which does not have any other inputs for heater hoses....

Where do I run the 2 heater hoses on my setup? Which one goes from the intake to the heater core and which one runs to the intake from the heater core?

THX

[Mike Holleman]

Brad, The 3/4 inch is the intake and the 5/8 the return.
Mike

[whytry]

Thanks Mike, I was thinking I have this weekend off and there is nobody working at Classic Air this weekend, so it might have been a wasted weekend....
THX....

Does anybody think it will be a future problem running the intake and return to almost the same spot on the intake?

[whytry]

Should I run the 3/4 to heater port #1 or heater port # 2?

[Mike Holleman]

Brad, Does your water pump not have a place for a threaded nipple? Usually the output or 3/4 pipe comes from the water pump and what you denoted as port 1 is the smaller return. Port two would be a bypass if the water pump had one. Hope this is some help.
Mike

[whytry]

No the water pump has nothing besides the lower rad hose opening. So how would I run the hoses?

[Steve68]

Off the intake,
#1 port you have marked, originally goes to the waterpump, and then one comes off the intake and the water pump to the heater core, but since your running the electric pump, I think you'll need a 90* fitting and make them both come off the intake,

[whytry]

Hey Steve, so what you are saying is turn the port #2 noted on pic and have a 90* fitting come off of that and run that to the heater core also right? Which one of the 2 ports would be the inlet to the heater core? The inlet to heater core is the 5/8" hose right?

THX again

[TD509EFI]

whytry,

I don't think that will work. You can only use one of the ports on the intake manifold for hot water out to the heater core. This is the pressure side. The return line from the heater core must have suction from the pump side. If the elctric pump doesn't have a return fitting for the heater you will need to use a tee fitting ahead of the lower radiator hose that goes into the pump, which is the suction side.

Check with your electric pump manufacturer to see if they have an alternate solution.

John

[whytry]

THanks John, I called Meziere and they told me to get a new Thermostat housing where there is an additional input for a heater hose return line above the thermostat. He thought a water neck from a Ford would work because some of them have this return line already built in...

THX

[KUL FIR CHICK N]

John is right, you need one port in the manifold and one in the return hose . If you put a port above the thermostat, you are still essentially on the pressure side of the pump. When the t-stat is closed you'll have heat, but when its open you'll loose flow. Since you don't have a port on the return of the pump, you will need to have a port installed on the right tank of the radiator. Many of the OEM's do it this way. The heater relies on the pressure drop across the radiator to get its flow.



Ryan

[whytry]

Ryan, so if I understand this correctly I need to get my return from the heater core to run to the lower radiator hose or directly to the radiator right to correct this? Right?

[KUL FIR CHICK N]

That's correct.

[whytry]

Thanks!!!

[whytry]

Pretty sure I have this resolved now. Thanks everybody. Before I button everything up I want to double check the placement of the water valve. It should be in the line coming from the motor to the heater core, not from the heater core to the return (lower radiator hose) right?

[KUL FIR CHICK N]

Correct.

[Chad-1stGen]

Let us know how well the heat works. Curious to see how much flow you will get on this.