I will be installing a Vintage Air unit in my 1972 Supreme build. Do I need to install a heater control valve or do I just plumb the core return straight into the intake on the passenger side rear?

 

A non AC car is not straight plumbed into the heater core, there is a restrictor there. Not including it will overpressure the core, leading to leaks. Converting it to AC would require a heater control valve, either OEM, or the one that Vintage Air provides. Theory answer is that, even with the blend door pointing away from the heater core, it's still there and hot without being able to have the flow shut off. OEM applications shut the valve off on "full cold," that's the bump you feel kicking it over to max cold.

Edit: I should say that the control valve IS the restrictor for AC cars. Non AC cars have restrictors, AC cars have valves, cars with blown heater cores have straight plumbing.

 

Thanks. I will likely use the one VA provides. It is easier to hide it. The OEM unit looks clunky and I want a clean looking install.

 

The need for a heater control valve depends on the design of the HVAC system you are using. The purpose of the valve is to shut off the flow of hot coolant to the heater core when you are using the A/C. Obviously using that function helps the A/C get colder, so why wouldn't you want to use one? In any case, the specific valve needs to match the control head. Olds used vacuum operated valves that could be either normally open or normally closed, depending on year and model. As far as I know, all the current VA systems use electric stepper motors, so you couldn't control the factory valve anyway.

 

That was my car many years ago, before I realized a restriction was needed.

 

I used the heater control valve that came with my VA system. I mounted to the firewall initially and ran the hose to the back of the intake, but I never liked the way it looked. Later, I rerouted it (along with the AC hoses) hidden under the fender (over the wheel well) and then to the back of the intake. I took the trouble to smooth out the firewall after taking off the factory housing, so it looked cleaner to me. The only thing I don't like about the system is the blue LED light that comes on when the system calls for cooling is pretty bright at night.

This is a '69 S factory air.

 

Thanks for the input. I too have smoothed the firewall. Sounds like your solution hiding it in the fender is the ticket.

 

I did the same thing.