Water Shut-Off Valves & Big Blocks

[Tom R.]

With the exception of 1968s 427s, were any big blocks with C60 A/C equipped with a water shut-off valve? Tech manuals lead the reader to believe they were but AIMs suggest otherwise.

[Wayne W.]

Re: Water Shut-Off Valves & Big Blocks

Sure, 67s certainly have them.

[Mike M.]

Re: Water Shut-Off Valves & Big Blocks

even the small block c-60 equipped c-2's had a vac. operated shut-off valve to the heater.if one elects to turn on the a/c, the valve is supposed to close off hot water to heater core. howver, the switch that activets the shut-off valve is ofter times non-functional. long island sells a good repo. mike

[Tom R.]

Certainly smallblocks but what about C3 big blocks *NM*

[Dick W.]

Re: Certainly smallblocks but what about C3 big bl

Tom, I believe that the application of water shut off valves pertains to small and large block engines alike. At least from the cars that I have judged and had in my shop.

[Joe L.]

Re: Certainly smallblocks but what about C3 big bl

Tom------

All 1963-71 Corvettes with C-60 had the water shut-off valve in the heater hoses circuit.

For 1972-74, no Corvettes had the water shut-off valve.

For 1975, only non-C-60 Corvettes had the water shut-off valve.

For 1976-82, all Corvettes had the water shut-off valve again.

[Tom R.]

Re: Certainly smallblocks but what about C3 big bl

Hey Joe:

You've confirmed my conclusions with the exception of 69-71 big blocks. The AIM shows heater hoses for big blocks without the water shut-off valve but the P&A does not differentiate. So, big blocks were delivered with water shut-off valves?

Apparently, the rationale for the use of water shut-off was inconsistent over this period (71-76). It appears as though engineers were testing the effectiveness of this device with 75 as a control (non A/C gets the valve) and afterwards they all get it!

The 73-77 tech manuals are out of wack.

[Joe L.]

Re: Certainly smallblocks but what about C3 big bl

Tom------

I just checked the 69-71 AIMs. The water valve is shown for C-60 with big blocks (sheet UPC C-60, D-6). It's not called out by part number as it is for the small block with C-60 but it's shown in the drawing. I don't know why it's not called out by part number. That would imply that the valve was part of the big block, non-C-60 installation but the valve was NOT part of the big block, non-C-60 installation.