Heater Hose Valve?

[Deerhunter30]

My uncle has a 1982 CJ7 and just completed a 4.3 TBI & 700R4 conversion. It's pretty sweet. He said that on his 4.2 he had some type of valve that kept the coolant from running through the heater core until the motor was up to temp. I looked at my 83 CJ7 and I have nothing like that. All my heater hoses go directly from the intake and pump through the fire wall. Have any of you seen anything like this?

 

[Inspector-Gadget]

Deerhunter30,

I don’t believe that a stock CJ-7 was originally equipped with a heater control valve. Perhaps the air-conditioned models had such a valve, but not the non-A/C CJ-7s.

The dash mounted heater-ventilation pull knobs merely control the positions of air directing flappers in the under-dash heater box and cowl intake.

There was a time, however when many vehicles did not have heater control valves. It was then not unusual to install manually operated valves to bypass the heater core during hot weather.

I recall seeing that done using nothing more that common plumbing hardware.

Perhaps someone added a heater control valve to your uncle’s CJ.

In any case, my 85 CJ, I-6, is like yours: there is no heater control valve.

Regards,

Gadget

 

[Deerhunter30]

He is saying that it is taking a long time to warm up to operating temperature. He wants to add one of these valves to help it get to operating temperature faster.

 

[Inspector-Gadget]

thanks for the prized input

OK…well that is entirely different question than was posed in your first post.

A heater control valve could be added, although my opinion is that adding a heater control valve will make a negligible difference in heat-up time.

The heater core doesn’t hold very much fluid as a percentage of the total cooling system capacity.

There are many manually controlled and vacuum-controlled heater valves from which to select. It would be merely a matter of doing the pluming.

Regards,

Gadget

 

[MudderChuck]

There are various types of thermostat housings on the Chevy (and Jeep). Some with a built in bypass, some without. The bypass allows a flow of coolant around the thermostat, which allows the thermostat to react to actual engine temp. (not just whats right near the themrostat). Sometimes the heater is used in place of a bypass (in the thermostat housing).
High places in the heater tubing and such will collect with air, messing with the coolant flow.

 

[Inspector-Gadget]