540 vette

Took the a/c out of my 72 BB and put one of those a/c delete boxes on the firewall. The heater core outlets come from the bottom as they do stock. How are these run.

Also if I decided to eliminate the heater core and have no heater hoses what do I do with the expansion tank connections. Should I just get rubber caps and put them over the ends.

And what is the thread size of the intake and the water pump.

540 vette

No help?

Alan 71

Hi 540,
Not sure about 72, I only have the info for 71.
In 71..The heater core pipes normally come out of the side of the core for bb non a/c cars. (pointed away from the rear corner of the engine)
I'm not sure how the pipe location will affect the hose routing.
The 71 bb hoses run the same as the sb hoses… from the core through a clip on the air box to the tank, and then through a clip on the apron to the engine.
Regards,
Alan

71sb.

540 vette

Thanks Alan, great picture as usual. My car was an original A/C car that I removed and put the a/c delete box on it. My hoses come out of the bottom like an A/C car. Does it matter which side of the core the hoses hook up to.

Alan 71

Hi 540,
On sb cars there are 2 size heater hoses… 5/8" and 3/4".
The larger hose runs from water pump to the overflow tank and then to the upper pipe on the core.
Does you're core have 2 different size pipes?
Regards,
Alan

540 vette

I have to crawl under the car to see. It will be what ever an A/C car has. What is the thread size. I have to get an angled fitting for the intake.

Alan 71

Hi 540,
In looking around it 'appears' to be 1/2" NPT.
Regards,
Alan

71 Green 454

You should have 5/8" and 3/4" outlets on the heater core.
The 5/8" hose goes from the heater core to the water valve. A 5/8" hose goes from the water valve to the intake fitting.
The 3/4" hose goes from the heater core to the rear of the overflow tank. A 3/4" hose goes from the bottom of the overflow tank to the nipple on the water pump.

If you keep your heater core in operation, I assume you're keeping a water valve in the circuit. Also, are you keeping the factory overflow tank?

Isn't the intake fitting for the 5/8" hose a straight fitting with 1/2" NPT?

https://corvetteparts.com/item/fitti...-5-8-1959-1982

Here are some pictures I created for someone that needed heater hose and A/C hose routing information:

540 vette

thanks for the pictures. The 72 dosen't have a heater control valve. And yes I would like to keep the expansion tank. I need a 45 degree inlet on the intake to use it with my fuel line. Thats why I needed the thread sizes.

540 vette

If I decided to not use the heater core and eliminate the hoses what would I do to the expansion tank.

71 Green 454

You could install a 3/4" hose fitting with 1/2" NPT at the intake and run a 3/4" hose to the rear of the expansion tank. Connect the 3/4" hose from the water pump to the 3/4" connection at the bottom of the expansion tank. Also keep the 3/8" hose from the radiator to the top of the expansion tank.

540 vette

Lets say I didn't want to run any hoses.

ddawson

I used this to bypass my heater core to the expansion tank.

http://www.ebay.com/itm/LS1-LS2-LS3-...BVnvt7&vxp=mtr

You just need a hose barb to finish the install.

This way water still circulates though the expansion tank.

71 Green 454

My suggestion was to keep the expansion tank and eliminate the heater core. Without the expansion tank, where would you add coolant?

540 vette

I never had a vette with an expansion tank. I am probably going to run the hoses I just ordered a 45 degree for the intake to clear the fuel line.