Getting hot when running A/C

[Wageslave]

Fans rotating in the correct direction? I only ask because I've seen it wrong more than once.

I am sure on rotation, as I have had it wrong in the past.

 

[pontiacgp]

if that rating is for both fans together I'd be putting a good pusher fan in front of the condenser

 

[Bobbystill]

It is possible, as I wasn't too impressed with the radiator. I am also wondering if the fans can't move enough air to handle the load of the radiator and condenser both. The cloud car fans leave a 6-8 inch gap at the top of the radiator that isn't covered.

Maybe try getting a shroud that covers the rest of the radiator core? That's a lot of area to not be pulling cool air through. Is the rest of the shroud you have sealed up against the radiator core?

 

[Wageslave]

Maybe try getting a shroud that covers the rest of the radiator core? That's a lot of area to not be pulling cool air through. Is the rest of the shroud you have sealed up against the radiator core?

After going and measuring, it is about 4 inches of uncovered radiator at the top. The shroud is sealed up tight against the rest of the core though.

 

[Wageslave]

Maybe try getting a shroud that covers the rest of the radiator core? That's a lot of area to not be pulling cool air through. Is the rest of the shroud you have sealed up against the radiator core?

I have a 10 inch aux fan that I could put on as a pusher, but the magical radiator zip-ties that hold it have been used and cut off already. If I went that route, I would probably need to go and buy a bigger one. That, and it started raining again so fun time with the car is over for a little while.

 

[Bobbystill]

I'm assuming the problem is not the A/C condenser, right? The car doesn't overheat unless you have the A/C on? If that's the case and your airbox/core support are all sealed up and you have all the valances and air dams, then you either need more fan or more radiator. I'm running a champion radiator and 16" fan on my 350 and it works great. I haven't hooked up my A/C yet, but my condenser is installed. With my 180 T-stat and the fan set to come on at 185 I have yet to see 190 degrees while driving in traffic and am regularly around 174-175 when cruising. I used to have a 190 T-stat and I rarely saw over 200. You could try a cooler T-stat, and see if that helps your fans stay ahead of the temp. I also have a 10" pusher installed but not hooked up in case I need it when I get the AC fixed.

 

[olds307 and 403]

My Plymouth Breeze fans cover the factory height and width rad quite well with the Cutlass top plate. The aluminum plastic rads usually cool quite well. I went with the wider A body replacement aluminum plastic because I knew it would cool better and it was cheaper.

 

[pontiacgp]

I'm running a champion radiator and 16" fan on my 350 and it works great. I haven't hooked up my A/C yet, but my condenser is installed. With my 180 T-stat and the fan set to come on at 185 I have yet to see 190 degrees while driving in traffic and am regularly around 174-175 when cruising. I used to have a 190 T-stat and I rarely saw over 200. You could try a cooler T-stat, and see if that helps your fans stay ahead of the temp. I also have a 10" pusher installed but not hooked up in case I need it when I get the AC fixed.

if you have your fan to come on at 185 with a 180 thermostat once your fan hits the 185 it will be on all the time cause you will need to have the temp drop to 170 to shut it off and it will never get there. As soon as you drop under 180 the thermosat will start to close and heat up the coolant in the engine

 

[olds307 and 403]

It definitely sounds like an air flow issue at low speeds. I would close in the fans completely to help direct air flow. I also added the GN rad surround flaps. Even with a half plugged rad, they brought temps down in a hurry, made the fans more effective, all the air must go through the rad. I stay within 10 to 15 degrees of the thermostat rating, a mile stone for this car. I switched to a 180 Robert Shaw high flow thermostat just because I like a buffer having all the issues running a 403 in this car.

 

[pontiacgp]

I like to keep the temp 190° to 210°, if you run too cold you get worse fuel efficiency, your motor oil becomes acidic due to not vaporizing the stuff out that needs to be vaporized......