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post #1 of (permalink) Old 07-16-2007, 12:56 PM Thread Starter
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Oil or water hotter in a 258?

I aquired an old dealer installed (?) AC system that I think may be better used as an auxillary heater than cooler. I was thinking of either using water or oil as the original lines are quite small compaired to a normal heater core.

The compressor mount is actually nice as it mounts the alternator higher than the compressor. It will keep the alternator out of the road spray and deep water.
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post #2 of (permalink) Old 07-16-2007, 03:24 PM
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In my 258 the oil and water temperatures stabilize very close to each other in moderate or hot weather. The oil may or may not get as hot as the water in cold weather - it depends on ambient temperature and the kind of driving. The water always gets hot faster.

More important is that oil doesn't transfer heat nearly as well as water. If it did we'd have oil-filled cooling systems with neoprene hoses and no worry about rust or freezing.

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post #3 of (permalink) Old 07-16-2007, 05:51 PM
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How cold do you get? Have you done the heater blower upgrade or does that work for your Jeep?

The reason I ask is I too have one of those AC units and intended to install it for its original purpose. I actually got the unit bolted under the dash but I realized that Id never again be able to get to anything behind the dash without dropping the unit. That seemed like a lot of work just to change a burnt out gauge lamp.

There was also an interference problem with the arm at the top of the accelerator linkage. I cut some off the top end of the arm about an eighth inch above the hole.

If you still decide to do it, I think Id go with the water so as not to cause a flow restriction for the oil.

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post #4 of (permalink) Old 07-16-2007, 07:26 PM
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I used the engine coolant as the heat source in my CJ7 and ran it through the underdash assembly. It worked great! But then... you know that....
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post #5 of (permalink) Old 07-17-2007, 05:50 AM Thread Starter
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I wasn't really kean on plumbing oil anyway unless it was at a considerable higher temp. I remember my little NSU had an oil radiator under the front bumper to suppliment the air cooling when you bought the TTS package.

In my area there realy isn't much sense in running A/C when you can just take the top off and lower the windshield. I seem to spend more time freezing in the jeep than cooking. I have the heaater upgrade and it does a great job defrosting the windshield or heating the floor but when plowing it's nice to leave the windows open so you can hear the diesels trucks comming in your area.
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post #6 of (permalink) Old 07-17-2007, 02:31 PM
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If you run oil through the cooler, you'll have more oil to empty and possibly more dirty oil left in the system each oil change. Water is heavier than oil, and I suspect has more heat content, might be more efficient transfer of heat into the radiator assembly. If you go to the junkyard, you may be able to find an auxillary heater from a schoolbus. They have a box with a small rad and a fan designed for heating interiors. Cheap source, assuming its in working shape.
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