[64speed]

So let me start off by saying my car does not overheat. Going down the road it runs 173-177. Sitting still with the AC off it never goes over 183 even when its 95 degrees out. Here is the situation involving AC. If I get stuck in traffic or idle with the AC on the temp creeps. I posted about this before but I have found the "problem" I just need to see if I am out of options. Yesterday I got stuck in downtown Clemson and it creeped up to 197 over the course of 20 minutes. I turned the AC off and it immediately stopped and went back to about 188 before I started moving again. When I got stuck at the other end of town same situation with AC but this time I used my foot to raise the idle to 1200-1500 and it stopped creeping. So it is obviously an airflow issue. I have the 15 inch Cold Case HD radiator. 18 inch clutch fan and Hayden severe duty fan clutch. Have I exhausted all my options or can I do something to make the air flow better to stop this totally? A bigger fan will not fit in that shroud and the shroud is sealed to the radiator with strip insulation

[Formulas]

pulleys possibly, raise roationale speeds of water pump and fan that way..

i dont know if there is a idle stop solenoid that is universal but when A/C is engaged it raises idle speed

[Gator67]

Stuck in traffic with A/C on for 20 min and creeping to 197 does not seem like a problem to me. That said, I was having a similar issue with my wife's 68 FB (temp would creep to 205+ with A/C on in traffic during the summer months) and addressed it by installing a small pusher fan directly on the condenser (wired so it operates when the compressor is on).

[steve25]

Question for the OP.
When you turn the AC on and your idle rpm drops due to the drain on idle Hp, what else would you expect to take place?
1) you have added another load to the motor.

2) with a engine driven fan and the drop in idle rpm you have cut back on air flow.

3) you have slowed down the water pump and the circulation rate.

As posted I would at least add a solenoid that that kicks in when your compressor does to up your idle
speed .
Hint, if your AC stays somewhat cold even though your idle has dropped, and you have some temp creep then that’s a sign that your air flow rate is not too bad, but at idle your water pump’s circulation rate
could be better.

[Singleton]

What's your idle rpm? With a manual trans you could raise it 100-200 rpm with no ill effects and see how that works out. Or an A/C solenoid like others have said.

[64speed]

My idle rpm is between 850-900. Turning the air on has little to no change of idle speed. I guess a fan on the condenser is worth exploring but won’t that obstruct even more radiator air flow when it’s off?

[steve25]

First off in my opinion you don’t have a problem here to fret about and yes installing another fan will help at idle, but likely block off needed air flow at road speeds even when not powered and free wheeling.

Bottom line, at idle even 215 degrees your motor is not too hot and your coolant mix since it’s under pressure is not boiling.
Stop thinking that such temps are death for a engine!

[Gator67]

Originally Posted by 64speed

My idle rpm is between 850-900. Turning the air on has little to no change of idle speed. I guess a fan on the condenser is worth exploring but won’t that obstruct even more radiator air flow when it’s off?

The fan I'm using is pretty small, and the car stays at around 185 or so when the A/C is off, even on the hottest days here in Arizona. It works well enough for us, though your situation may be different. Having said this, although the fan and additional wiring is basically invisible unless you look for it, I prefer simplicity, and so I'll revisit it at some point when move my other projects forward.

[Gator67]

Originally Posted by steve25

First off in my opinion you don’t have a problem here to fret about and yes installing another fan will help at idle, but likely block off needed air flow at road speeds even when not powered and free wheeling.

Bottom line, at idle even 215 degrees your motor is not too hot and your coolant mix since it’s under pressure is not boiling.
Stop thinking that such temps are death for a engine!

yeah, I agree with this. The only reason I added a fan is because my wife drives her bird and I wanted an extra margin of safety...she doesn't monitor the gauges like I do.

[64speed]

Originally Posted by steve25

First off in my opinion you don’t have a problem here to fret about and yes installing another fan will help at idle, but likely block off needed air flow at road speeds even when not powered and free wheeling.

Bottom line, at idle even 215 degrees your motor is not too hot and your coolant mix since it’s under pressure is not boiling.
Stop thinking that such temps are death for a engine!

I agree it’s a non-issue…to a point. I can just turn the air off and it stops dead in its tracks and then goes back down but isn’t the point of AC to have it on when it’s hot as hell.

[Singleton]

Originally Posted by 64speed

but isn’t the point of AC to have it on when it’s hot as hell.

I think the point being made is that even a (temporary) 215 temperature is nothing to worry about, or a reason to turn the a/c off. The factory overheat warning light didn’t come on until 240-245 in these cars, and the Pontiac engineers didn’t consider anything under 260-265 as engine damaging temps.

[b-man]

Run it and stop worrying about it getting above 200 degrees with the A/C blasting.

Even 220 isn’t that bad.

Once it hits 220 or 225 then shut off the A/C for a while.

197 degrees is nothing.

[geeteeohguy]

Originally Posted by 64speed

I agree it’s a non-issue…to a point. I can just turn the air off and it stops dead in its tracks and then goes back down but isn’t the point of AC to have it on when it’s hot as hell.

Remove the gauge, install the factory temperature light, and enjoy your car worry free for the rest of your life.

My '67 has the light and it never runs hot or overheats.

[b-man]

Cold Case does make a 17-1/2” Severe Duty radiator with twin 1-1/4” tubes instead of the 1” tubes.

Unfortunately you didn’t either source a core support that accepts the 17-1/2” factory air conditioning/Heavy Duty cooling option radiator, or convert your standard core using the bottom piece offered by Cold Case or Ames.

Every little bit helps, especially with the early A-body cars with limited radiator area and down flow design.

In order to use the Severe Duty radiator in my Le Mans with factory air conditioning I had to use the ‘66 upper hose and thermostat housing. That radiator has the more efficient upper inlet on drivers side unlike a ‘64-‘65 radiator.

[64speed]

That’s what I have.

[b-man]

You said you have a 15 inch Cold Case HD radiator in your original post.

So which is it?

[64speed]

I am using the 66-67 style drivers side inlet is what I mean. It is the smaller core (15 inch) but the inlet is on the drivers side. That was the first solution offered me by Cold Case when my first engine wouldn’t cool at all.

[72projectbird]

197° in traffic with the AC on? Pfft that's not a problem.

[65 Lamnas]

Find a smaller WP pulley. It'll increase the air and the coolant flow.

[steve25]

Raising his idle speed will provide the same result as the above and consume less power when the vehicle is moving.