Heater Shut Off Valve

[likeold]

I'm thinking of installing a heater shut off valve on the hose to the heater to try and cool the cab down a bit in the summer heat.

Is this a good idea? Do I just put it on one hose feeding the heater, does it matter which one (in/out)?

Will this change the engine operating temperature?

Any idea on a good shut off valve?

Thanks

[michealbernal]

I bought one some time ago at NAPA I don't know if they still have them.  It would be helpfull if we knew what the make and model of the vehicle you are working on is.  As long as your cooling system is in good shap it should not change the operating temp.

[EmTee]

I added one to my '38 Century.  I just bought the proper size ball valve and nipple at the hardware store.  I screwed the hose nipple into the output side of the valve.  I put mine on the hot side at the thermostat housing.  I haven't seen any difference in engine temperature since I have closed the valve.

 

Unfortunately, the interior isn't significantly cooler either...  What I discovered is there's a fair amount of hot air leaking in around the brake and clutch pedals.  I'm considering installing an exhaust wrap (as used on tubular headers) on the head pipe from the manifold down to where it turns under the floor.  I also need to figure out how to better seal the pedal gaps.  Maybe something like these: http://www.oldbuickparts.com/product_info.php?products_id=2393

[Steve_bigD]

I used this Four Seasons valve and mounted it on the hot or upper hose.

 

https://www.amazon.com/gp/product/B000DCNGKQ/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

 

Works great and does help cool the interior in summer but I also have the rubber seals on my pedals that EmTee mentions.

Steve D

[likeold]

Steve, That looks like what I need, nice neat and solid. Does it screw right into the top hole on the water pump without any issues?

[Steve_bigD]

Yes it screws right in to the top hole which is actually on the thermostat housing. Since it's tapered there is some adjustment to allow getting it oriented in the right position for the hose routing. Here is a photo of my engine:

 

 

Steve

[neil morse]

Just be careful that you are ordering a valve with a 5/8" nipple for the heater hose.  Some of them have a 3/4" nipple.  (Don't ask me how I know. 😜)

[likeold]

12 hours ago, Steve_bigD said:

Yes it screws right in to the top hole which is actually on the thermostat housing. Since it's tapered there is some adjustment to allow getting it oriented in the right position for the hose routing. Here is a photo of my engine:

 

 

Steve

Okay thanks, I will order one of these. Your engine picture brings up another question. You have a oil fill breather cap, is that what should be on these engines? Mine is not a breather, looks more like a radiator cap. 

[EmTee]

My '38 also has the closed cap, which is correct.  The valve cover is vented on the end next to the firewall.  I think the breather cap was used on later engines.  Adding a breather cap doesn't hurt anything, but technically isn't correct for 1938.

[Steve_bigD]

Yes, the breather cap is not correct for 1938 but with a draft tube system I felt the any additional crankcase venting will help. The vent on the rear of the valve cover seems might skimpy to me and mine is not a show car.  However there is also a second vent at the lower left side of the block which is filled with a steel wool filter so probably that together with the rear valve cover vent is adequate. Maybe I'll go back to the closed correct cap.

 

Steve D

[likeold]

Installed my heater shut off valve today. I really like the set up and the cab was so much cooler on a long drive. The engine stayed at 180 the whole time. Thanks for the advice.