Improving the cooling on our TJs

here is my solution I have used on many street rods with aftermarket air. Put a 4 port heater control valve in line. This allows water to still circulate in the engine but keeps the hot water out of the heater core. Run a vacuum line and tee into the recirculate door, when you put on max a/cut will shut off the water to the core.
https://www.amazon.com/dp/B07CV9ST77/?tag=wranglerorg-20
 
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My plan is to use something manual and ugly like this:
https://www.amazon.com/dp/B0989DJLXJ/?tag=wranglerorg-20.

I dont mind switching it manually. Vacuum lines can be done, the same as electric solenoid, but for something that needs to be changed once in a month in a best case, I can use my hands and access engine bay.

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here is my solution I have used on many street rods with aftermarket air. Put a 4 port heater control valve in line. This allows water to still circulate in the engine but keeps the hot water out of the heater core. Run a vacuum line and tee into the recirculate door, when you put on max a/cut will shut off the water to the core.
https://www.amazon.com/dp/B07CV9ST77/?tag=wranglerorg-20

I thought of doing this EXACT thing … where did you get the fittings for the HVAC vac line ???
 
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I thought of doing this EXACT thing … where did you get the fittings for the HVAC vac line ???

Use a small vacuum hose like for the windshield washer hose (3/32” I think) use a small plastic tee to tie it into the factory system. A couple ways to do it. You can cut the plastic hose a few inches back from the factory vacuum motor then use short pieces of rubber hose to tee it in. Use a drop of superglue or spray the plastic with a carb or brak cleaner then pish the rubber hose on. This will keep it from sliding off. Or you can pick up a dual size vacuum tee and just disconnect the hose from the vacuum motor and tee it there. I’ve do it both ways and both work equally as well. The #68517 in the upper right of this assortment is what you are looking for. I do not like the large break off tees as the are too big to make look nice. Check at your local auto parts store for a small assortment or a self serve auto wrecking yard look for any American car.
https://www.amazon.com/dp/B07CSGK8XK/?tag=wranglerorg-20.
 
Just an FYI your AC condenser may Ice up in high humidity without any coolant flow thru the heater core.

Did you mean evaporator? I have done this to many vehicles in Southern California and never had that concern. Maybe an issue in Florida or the south but easy enough to switch the A/C to outside air if it iced up.
 
Is the factory radiator copper/brass or is it aluminum? I've always been told copper/brass dissipates heat better.

I think brass, which are hard to come by.

Sorry I was thinking about the heater core.
 
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Electric fan that will be as powerful as the mechanical one
There isn't one made that fits in the TJ radiator support.

It seems that on our Jeeps the cooling system/thermostat is running wide open once it’s warmed up.
That rarely happens, unfortunately people say it allot so it must be true. Thermostats are running about half open or feathering at operating temp. Blaine removed the thermostat and the Jeep would not get to operating temp ever so obviously it's not wide open normally. Remove yours and drive it around, let us know what wide open really looks like.
 
That rarely happens, unfortunately people say it allot so it must be true. Thermostats are running about half open or feathering at operating temp. Blaine removed the thermostat and the Jeep would not get to operating temp ever so obviously it's not wide open normally. Remove yours and drive it around, let us know what wide open really looks like.

I did run my TJ for couple of weeks w/o a thermostat. It heats up slower and will not be able to reach to operating temperature of 210F if it is not hot enough outside.
However, if it is hot outside with AC on, having thermostat and not having a thermostat does not matter - it goes into 210F area.
 
There isn't one made that fits in the TJ radiator support.


That rarely happens, unfortunately people say it allot so it must be true. Thermostats are running about half open or feathering at operating temp. Blaine removed the thermostat and the Jeep would not get to operating temp ever so obviously it's not wide open normally. Remove yours and drive it around, let us know what wide open really looks like.

Been there done that, a few times in a few Jeeps (part of my flush strategy) … Jeep runs too cold yet too hot without a thermostat (with a sub par radiator)… if it’s cool outside, it will never heat up, if it’s hot then it will hit and possibly surpass 210. This is how I KNOW the radiator is crap. There is no overhead for AC and hot weather with a cheap parts store radiator.

Yes thermostats are slower moving than the temperature that passes by them. But regardless they are modulating devices. If the thermostat is wide open during normal operation, then your cooling system is maxed out. And you have a runaway thermal issue. Luckily physics allows a radiator to do its job better the hotter it gets, greater temperature difference …
 
I think that the most point about the thermostat is to understand that it’s sole purpose is to prevent from the engine running below operational temperature.

I’d expand on that and state that it’s designed to set and maintain the operating temperature of the coolant … it both causes the coolant heat up to a certain point and cool to a certain point, it modulates …
 
I’d expand on that and state that it’s designed to set and maintain the operating temperature of the coolant … it both causes the coolant heat up to a certain point and cool to a certain point, it modulates …

Agree. However, if we look at situation where the coolant will be at 220F, it will no longer modulate or influence anything. The moment that cooling systems capacity is exceeded, the thermostat has no role anymore
 
Is the factory radiator copper/brass or is it aluminum? I've always been told copper/brass dissipates heat better.
You were told correctly. The later TJ radiators are aluminum cores with plastic tanks. Until recent technology finally found a way to improve the connection of the fins to the rows of tubes, the aluminum cores worked better for a basic and simple reason. Lead is a very poor conductor of heat and all the fins were soldered to the tubes with lead solder.
 
Can somebody explain or post a picture of where a hole should be drilled in a thermostat? Also I have seen the size mentioned as being 1/16 or 1/8, which is best?