[65 Lamnas]

Most folks don’t want an idle speed of 12-1500. Even the factory put smaller WP pulleys on the A/C cars vs non A/C cars.

[b-man]

Originally Posted by 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.

And I’m sure it’s likely the best radiator they could have sold you considering the major constraint being the standard 15-1/2” core support. The coolant flowing diagonally is a little better design than the original ‘64-‘65 with both hoses on the passenger side.

When I called Cold Case they recommended the Severe Duty twin 1-1/4” tube radiator that only came with the ‘66-‘67 inlet and outlet that only fits the 17-1/2” core support. I don’t think the Severe Duty radiators come in any other configuration.

Unless you’re into swapping core supports or upgrading your current one to 17-1/2” you already have the best radiator for your situation and honestly it’s not really working all that badly.

[geeteeohguy]

Originally Posted by 72projectbird

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

Agree 100%. He's chasing ghosts.

[Schurkey]

Originally Posted by 64speed

My idle rpm is between 850-900.

Originally Posted by steve25

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

Originally Posted by 65 Lamnas

Most folks don’t want an idle speed of 12-1500. Even the factory put smaller WP pulleys on the A/C cars vs non A/C cars.

Thank you. I'd be mildly unhappy with an 850--900 rpm idle, let alone raise it higher.

[b-man]

There’s a good reason why the air conditioned cars all had a smaller diameter water pump pulley.

I forgot the reason…..

[CYNHIKER]

b-man, do you have the part number for the Cold Case Severe Duty radiator?

[b-man]

Originally Posted by CYNHIKER

b-man, do you have the part number for the Cold Case Severe Duty radiator?

GPG38AS

I checked their website and saw GPG38A but I’m thinking the S added to the part number is what designates Severe Duty with the 1-1/4” tubes. Keep in mind my application is for automatic transmission.

https://www.coldcaseradiators.com/pr...tor?sku=GPG38A

Call sales at Cold Case to confirm but that should be the same exact one I purchased.

[dataway]

When I was 20 years old and my GTO was a daily driver, on really hot days ... I'd just put it in neutral when I came to a stop, usually the extra 200 rpm or so was enough to keep it cool with the AC on.

[Gary H]

Originally Posted by dataway

When I was 20 years old and my GTO was a daily driver, on really hot days ... I'd just put it in neutral when I came to a stop, usually the extra 200 rpm or so was enough to keep it cool with the AC on.

And, if an automatic transmission, helps by not loading the convertor which builds heat.

[steve25]

Hey gang, he’s got a manual trans !!
I can’t see why an increase of 150 rpm is an issue to reset the carb or FI to for just the hottest summer months.

Maybe even just 100 rpm more then his current idle speed will give him the non temp increase he’s looking for.

[VCho455]

Maybe his problem is being caused by hot air from the radiator being recycled back through the radiator when the vehicle is stationary. Our cars were not designed to sit in today's traffic. New cars are engineered to prevent or at least minimize hot air being recycled through the radiator.

[carbking]

The easy solution is to place a piece of electrians tape over the temperature gauge display!

Jon

[242177P]

Originally Posted by VCho455

Maybe his problem is being caused by ...

His problem is the digital readout. You can watch
the temperature rise degree by degree. It went up.
It went up. It went up. Cars were never meant to
stay at a fixed temperature, and using the AC on a
hot day is gonna make it move. Can't remember
which desert we crossed, but it had signs warning
against using AC. I wonder why...

[STEELCITYFIREBIRD]

Do you have a fan shroud?
My thought process is to increase fan efficiency at lowest rpm.
An idle speed ‘booster’ solenoid is how engineer's combated this issue…what do they know 🤔
✌🏼

[jhein]

From what you said, it sounds like you're not worried so much about the 197 temp but more worried about the fact it may keep going up until you overheat. If that's the case, just test it. Get it fully heat soaked then return to your driveway and let it sit and see what happens. You may find that it will reach a limit and not overheat.

I don't have AC but here's what my car does. I have a OEM style radiator 180 deg thermostat and a flex fan (not sure of the diameter) and a factory shroud. The motor runs at 180 at all times while moving at any speed. At a stop, it will climb up to about 190 fairly quickly. But, it never goes higher. I almost never have to stop for more than a couple seconds at a stop sign but every now and then there's road work going on and I may have to stop for a couple minutes. The first time I watched my temp climbing up quickly I got a bit nervous. But then once I got moving again it came right down. So anyway, I tested it like I described and it climbs up to maybe 190-195 and just stays there. Doesn't keep climbing. So give it a try and see what happens.

Also, are you running vacuum advance? If so, is it connected to ported or manifold? Manifold will run cooler at idle. Also, depending on your driving conditions, radiator fins can get clogged up with bugs and debris that can affect cooling especially at a stop. Probably not the case with your car but you never know.

[64speed]

Originally Posted by jhein

From what you said, it sounds like you're not worried so much about the 197 temp but more worried about the fact it may keep going up until you overheat. If that's the case, just test it. Get it fully heat soaked then return to your driveway and let it sit and see what happens. You may find that it will reach a limit and not overheat.

I don't have AC but here's what my car does. I have a OEM style radiator 180 deg thermostat and a flex fan (not sure of the diameter) and a factory shroud. The motor runs at 180 at all times while moving at any speed. At a stop, it will climb up to about 190 fairly quickly. But, it never goes higher. I almost never have to stop for more than a couple seconds at a stop sign but every now and then there's road work going on and I may have to stop for a couple minutes. The first time I watched my temp climbing up quickly I got a bit nervous. But then once I got moving again it came right down. So anyway, I tested it like I described and it climbs up to maybe 190-195 and just stays there. Doesn't keep climbing. So give it a try and see what happens.

Also, are you running vacuum advance? If so, is it connected to ported or manifold? Manifold will run cooler at idle. Also, depending on your driving conditions, radiator fins can get clogged up with bugs and debris that can affect cooling especially at a stop. Probably not the case with your car but you never know.

Exactly! I am wary of finding out what my upper limit is.

[b-man]

By staying with the 15-1/2” core support you limited yourself to not only the smaller radiator with 1” tubes instead of 1-1/4” tubes but you’re also missing out on the larger 19-1/2” fan.

If you want the additional peace of mind and cooling capacity of the bigger more efficient large tube radiator and 19-1/2” fan plan on spending whatever it takes to replace or modify your core support and upgrade your cooling system.

It’s not a big deal finding out what your upper limit might be, don’t be shutting it off at 197 let it hit 220 before you shut it down next time. 20 minutes sitting in traffic with the air conditioner running and only hitting 197 seems like you’re doing fine to me.

[jhein]

Originally Posted by 64speed

Exactly! I am wary of finding out what my upper limit is.

That's the source of your stress right there! Man, have I felt it. You could correlate my heart rate to my water temp gauge. Test it and see. Maybe (probably) it's fine. If not, you need to know,

[64speed]

If I buy a condenser fan do I want it to push or pull?

[242177P]

Originally Posted by 64speed

If I buy a condenser fan do I want it to push or pull?

An extra fan is no magic bullet. If it
can't move at least as much air as
your existing fan I'd wager you just
created an airflow restriction.