Can I use heater hose cutoffs without damaging the engine? I'm talking about the little valves that mount inline and can be opened like

a faucet. They're mainly used for stopping flow to the heater core to increase the output of the a/c system. My AC is marginal

to fair, and I figured any little bit could help. I'm just wondering if it will overheat the engine?,,,,BB

I can hear the crickets........So no one has ever used these, or blocked off the outlets on the block and radiator for racing purposes? Hmmmm.,,,,BB

Your AC should have nothing to do with your heater core.



If your AC isn't functioning properly then figure out why. You could possibly need a new compresser. Test each component per FSM and then recharge the system.



But to answer your question, no it shouldn't hurt your cooling system. You would have to put the valves on both sides of the core for it to be effective. It would simply bypass your core and the system would preasurize the same.

unlike a newer car, the 1st and 2nd gens have heater valves, so when the heaters off theres no coolant circulating thru the heater core anyways



newer cars, always circulate water thru the heater core, so its always hot, and then use doors in the heater box to vent air over em or not

Is this valve located somewhere in the heater hard lines on the firewall? I see nothing like that, unless it's under the dash? Looks like it's

always circulating to me, is what I meant.,,,,BB

its under the dash, off the top i'm not sure if its on the outside of the heaterbox or right on the inside. on an 84-85 its a BIG job, but its not all that hard