When I mean by kill, I mean just dont run fluid through it. I made another post asking for some sort of diagram on the cooling systems on these cars, but I assume no one has one. Plus I think I may have figured it out. Fluid from the front of the intake goes to the value, and then from the valve to the heater core unless a vacuum is applied (I dunno what applies the vaccum). When theres a vaccum, it shuts off the line to the core and opens the one that goes back to a T. Then at the T, one end goes to the oil cooler (exchanger I suppose, if its hot fluid) and the other to the heater core, which I suppose wouldnt. So, unless there is a check valve at this T, that means the heater core is always going to have pressure on the lines, whether there is vacuum or not. It may not flow fluid when there is vacuum, but because the bottom nipple on the valve is flowing to the T, without a checkvalve it just builds up pressure at the core anyway.
So maybe thats a reason why the cores fail so often, whereas in the truck, pressure doesnt build up when the AC is on. Fluid goes from the intake, thru the core, then back to the waterpump.
Correct me if Im wrong in all of this BTW.
Also, I took off this valve, and even with no vacuum applied, fluid flows out both the top and bottom. Less on top, but there is still a slight leak. Is that normal, or is it just not seating correctly now when theres a vacuum?

 

I can't comment on the flow path, but you should know that this unit is actually an oil WARMER, Think about it.

 

Well, that depend on the oil temp, right? But you are not wrong...it attempts to keep the oil at the same temperature as the coolant. So if the oil is colder than the coolant, than it would heat the oil. And if the oil is hotter, it will cool it.

 

yea I know, calm down. The flow matters whether it would be a cooler or not. If it comes directly from the radiator, it would be sort of a cooler. Otherwise it wouldnt. And it looks like fluid is moving from the valve to it, then to the radiator.
The question is it ok to bypass it and the core for now. Which is probably ok.

 

Get a clean enough head shot to scramble the brain and it'll never feel a thing, otherwise, yeah it's gonna hurt.......

 

So really, it is bad to not flow coolant thru that thing?

 

No, it's not bad, I was just making a joke about if it would "hurt" , as if the cooler could feel pain.

I've seen a LOT of small block chevy engines run just fine without it

 

Of course you can bypass it.