Ok, I have a 180* stat right now. It's getting colder out and now that I'm using the heat (what I have) I don't really like.

Now, reason I put a 180* in was because I plow in the winter and going down the road at 55-60mph for any more that a couple miles I'd start to get hot from the blockage of airflow with the plow on. Around 220*ish.

Now to the main concern, from what I have found searching (yes I said "searching") the temp gauge seems to be reading normal for the 180*. I've checked several places in the cooling system (radiator, hoses, heater hoses, thermo housing) with a IR temp gauge, and the hottest I've got a reading on was 145*.

Also, the heat coming out the vents is around 135* holding rpm's at 2000-2500. A couple seconds after droping back to idle the heater temp drops to about 105*. This being checked with a meat thermo. stuck in left most vent under headlight switch.

This seems low to me. Shouldn't it be closer to 180* at motor and rad.? And closer to maybe 130*ish at idle? Or, is it possible the temps would drop that much through heat exchange.

BTW: I'm thinking about going back to a 195*. Opinions?

 

Do you have the stock clutch fan ? I run dual electrics and it is as easy as turning the set screw on the thermostat in the fall and in the spring .

 

Yup. Stock clutch fan.

 

I think nominal heater outlet temp with a 195 thermo is around 150-155... so, a forty some degree drop shouldn't really be surprising. You aren't 100% efficient there in any event. (at the heater core) As the air gets colder, efficiency increases, but, all that means is that the amount of temp change of the incoming air is greater, not necessarily hotter out the vents. (if you start with 10* air, warming it to 80* thru the heater core is actually pretty good.) Also, keep in mind, that change in temp across the heater core is directly proportional to the difference in temp of the incoming air, and the core temp.

Running the 180 stat because you plow is only postponing the inevitable. It gives you a few more minutes before things start getting "too" warm. I would have a close look at you fan clutch, and make sure it's working correctly. It DOES rely on air flow though.... but, I would think that NO airflow thru the engine compartment would be just as effective..... the engine warms the air in there rather nicely. E-fans might not be such a bad idea for ya.

 

Well, postponing is all I really need. Most I travel with it on is 20 miles or so, and thats only on occasion. Mostly about 10. It was starting maybe 2-4 miles into the drive. With the old 195* I could turn the heater on high and it would keep it around the 220* mark. Also, while plowing the temp never rose. Was just while traveling for a distance. Around town, no problem. As far as elec. fans (direct fit)... be nice, but don't have the money. I do have a set of dual elec. fans that I was going to put in as auxilarys on a toggle but they won't fit between the condensor and grille.

EDIT: Looking through Summit I came across 2 fans that I could run as aux. A Proform (pro-67010) for $45 and has 1000 CFM and the other is a Flex-A-Lite (flx-112) for $80 and has 1105 CFM. I'm thinking of going back to a 195* and doing the Proform fan on a toggle between the grille and condensor for when it gets too warm.

 

Do you have the aux trans cooler between the condensor and the radiator?

 

Yup. I measured the space between the grille and condensor and have 3". Figured I'd turn it on if/when it started to get hot and shut it off when not needed.

 

if you really want to get hotter air out of the vents, do this:
1. Unplug the connector from your AC compressor on the accessory bracket.
2. Run on the "Max AC" setting.

It will recycle the hot air blowing out of the vents. That way you are not trying to take 25* outside air and make it warm.

 

Thought about that too. Seen a thread about it (think it was you). The only thing is the whole "life of compressor" debate with it kicking on and off to keep things working. My A/C works and I'd like to keep it that way. If there is no downside to unplugging it, then I may just do that, or at least try it.

 

You can make a toggle switch in the cab. Run the wires from the harness to the switch in cab, then back to the compressor connector.