vmsns007

Have been reading old posts about installing a ball valve to cutoff the flow of hot water from intake manifold to heater core to help with cabin heat (something im struggling with).
Some posts imply that some years have a heater valve already installed ?? Or am i misreading what kind of valve that is ? Was there a factory installed hose bypass ?

If not - anyone know what size valve i need to pickup and best place to put it inline ? Any valve recommendations ?

Thanks all !
Hoping my newbie posts slow as i knock out things

Blue73Shark

Some info in this recent thread may be of help:

https://www.corvetteforum.com/forums...ere-is-it.html

Fran

Mooser

For a manual valve, look for a ball valve with 3/4" barbed (crimpex) ends.

Homedepot




Some place it by the water pump (some even us a pipe thread on one end and screw it into the pump)
Mine is placed by the heater core since I wanted it a little more unobtrusive


Just remember to open it now and again to flush out the core etc.
M

vmsns007

Thanks much Fran - that helps clear things up.

Any guidance in what size ball valve to buy for installing on heater hise from manifold to core ? Looking for the inside diameter of that heater hose on a 74 to buy the right size valve.
If anyone has a recommendation on a valve they like what apprexiate as well.

<<EDIT>>. Looks like i was typing this at same time post above andwering my wuestion. Thanks !!

vmsns007

Last question from me on this - i've seen guidance to install valves on the supply hose from manifold only and others say to install valves on both hoses.

Is there value in blocking both hoses ?

Mooser

There has been a fair amount of debate on which hose to block, if a return loop should be made, etc. etc. etc.

Once one line is blocked, the coolant will not go through the core and it will just sit in the two lines without moving. There will be some heat transfer from the engine to the fluid in the lines but not anywhere near what it would be like it would be if that fluid was actually going through the motor.

I would say most just block the one line which is also the way the original AC valve worked
M

Street Rat

I used two valves on my '81. We don't need a heater in Central Texas right now. Heat index is 110 degrees today. This picture was taken with the valves open during the winter. I purchased my valves and fittings from McMaster-Carr online.

Dodosmike

On my '78 I have a stainless 1/4 turn ball valve on the hose out of the water pump. I think I bought it at home depot. Its not fancy, and I could have bought something smaller and hidden it better, but for me, it works. Just be sure whatever valve you buy can take the heat generated by your car.

If I can find a pic I'll add it later.

Some people disconnect the blower fan as well.

Iceaxe

That's the same shutoff valve I used. Here is the complete information and part number.

Dahl Brothers Canada LT Valve 3/4crimpex
(MODEL #121-PX5-PX5-BAG)

vmsns007

thanks for he replies folks. Very helpful. A qucik look at the Dahl website shows it appears the part number has been replaced with this

http://www.dahlvalve.com/products/mi...21-PX5-PX5.php

I searched home depot, lowes, and menards websites and didnt see any brass 3/4 inch pex braided inlet ball valves. Next stop a local plumbers supply

bmans vette

I had a 67 Camaro that the PO disconnected the heater and routed the heater hoses to a smaller radiator in front of the main radiator.
It helped cool the intake manifold a little more and eliminated any cabin heat from the core.
It also of course, eliminated the defroster.
The car had no a/c.
This was before a/c was standard in all cars.
We just used the "470 alternative a/c unit" - 4 windows and 70mph....

I also had a 63 Buick Skylark that had a manual shutoff on the hose going to the heater from the water pump. It helped in the summer.

vmsns007

Why disconnect the blower fan if i have that switch on the console all the way to the far left (off) setting ?

Dodosmike

Can't comment on your year, my 78 doesn't shut off, only "low".
If the valve is open I'd always have heat blowing. No "off".
If I shut off the valve, the fan will still blow warm air into the car. So I unplug it. I'll put it back together in the fall on the cool nights.

Msbfdx

Here is what I built. It's design provides for circulation from pump to manifold while bypassing heater core.

vmsns007

found 3/4 ball valves at local plumber supply and got them installed today. Long drive this PM and i can already tell a difference with less heat in cabin. Thanks for all guidance getting this done. Hope to also Dynamat this Winter if all goes as planned