[64speed]

I have the large crank pulley. I just called Cold Case and they gave me a list of like 6 things to check. They told me it wasnt worth upgrading the radiator because as slow as it was heating up that the cooling system was doing its job but that I had another problem. First task is to put a 180 back in it per their recommendation with a 1/8 hole drilled in the rim. Fill the block up with coolant while the thermostat is out and try to burp it one more time. They also said that with 250 miles on it I want truly know anything until 1500/2000 miles and just to drive it. The temperature drops like a rock if I turn off the air and drops even faster if I turn the heat on so thats where we are at right now.

[Murf]

Originally Posted by 64speed

I have the large crank pulley. I just called Cold Case and they gave me a list of like 6 things to check. They told me it wasnt worth upgrading the radiator because as slow as it was heating up that the cooling system was doing its job but that I had another problem. First task is to put a 180 back in it per their recommendation with a 1/8 hole drilled in the rim. Fill the block up with coolant while the thermostat is out and try to burp it one more time. They also said that with 250 miles on it I want truly know anything until 1500/2000 miles and just to drive it. The temperature drops like a rock if I turn off the air and drops even faster if I turn the heat on so thats where we are at right now.

Boy, they seem pretty smart to me. Especially that part about “get some miles on it before you do anything “. Sounds familiar to me. 😁

Relax & have some fun!
Murf

[grivera]

Originally Posted by 64speed

I have the large crank pulley. I just called Cold Case and they gave me a list of like 6 things to check. They told me it wasnt worth upgrading the radiator because as slow as it was heating up that the cooling system was doing its job but that I had another problem. First task is to put a 180 back in it per their recommendation with a 1/8 hole drilled in the rim. Fill the block up with coolant while the thermostat is out and try to burp it one more time. They also said that with 250 miles on it I want truly know anything until 1500/2000 miles and just to drive it. The temperature drops like a rock if I turn off the air and drops even faster if I turn the heat on so thats where we are at right now.

Assuming you have the full strength coolant mix it with distilled water before putting in radiator to get even mixture.

Also, did you ever put a timing light to it for idle/vacuum advance timing measurement?

[64speed]

Originally Posted by grivera

Assuming you have the full strength coolant mix it with distilled water before putting in radiator to get even mixture.

Also, did you ever put a timing light to it for idle/vacuum advance timing measurement?

My timing light sucks and I can’t see it. Waiting on my nephew to come.

[tom s]

too small bottom and too big water pump IMO.Tom

[64speed]

It only runs over temp of thermostat when the AC is on

["QUICK-SILVER"]

Originally Posted by 64speed

It only runs over temp of thermostat when the AC is on

With AC running the condensor raises ambient air temperature before it goes through the radiator. Takes more air and water flow to maintain cooler temps.

Hence the reason AC cars came with AC pulleys.

Three groove pulley doesn't mean it's the right size. Need to measure it and see for sure.

Clay

[ZeGermanHam]

Originally Posted by "QUICK-SILVER"

Three groove pulley doesn't mean it's the right size. Need to measure it and see for sure.

Clay

I just found that out for myself a few days ago. I ordered a billet pulley set for late 1969-70 with PS & A/C. I have a complete set of OEM pulleys to compare with, and as you know, the factory stacked a smaller diameter single-groove A/C crank pulley behind the 2-groove WP/Alt crank pulley.

When I measured my new billet 3-groove crank pulley, I noticed that it was significantly smaller than my OEM 2-groove WP/Alt crank pulley. I soon figured out that rather than machine the billet pulley so it has a smaller diameter section for the A/C belt like factory, they just sized the entire thing down to match the smaller diameter of the A/C crank pulley. This means that it will spin the water pump slower than the OEM crank pulley would. I was kinda bummed about that. They should size them up to match the OEM WP/Alt crank pulley size, not size them down to match the A/C crank pulley size.

[68WarDog]

Originally Posted by ZeGermanHam

I

The crank pulley looks small thats offered in the aftermarket (6"). Why would anyone want to underdrive the waterpump and alternator?

[ZeGermanHam]

Originally Posted by 68WarDog

The crank pulley looks small thats offered in the aftermarket (6"). Why would anyone want to underdrive the waterpump and alternator?

The billet crank pulley in my kit is 7-5/16", which is the same diameter as the OEM single-groove A/C crank pulley that would've been stacked behind an 8" 2-groove WP/Alt crank pulley. Wish they had just sized the thing up to 8" rather than size down to 7-5/16". Or better yet, machine the thing so it functions identically to the OEM setup and has two different diameters.

[Singleton]

Originally Posted by 68WarDog

Why would anyone want to underdrive the waterpump and alternator?

Typically, Pontiac had their non-A/C engines underdriven by 8 to 15%.(water pump driven at 85-92% of crank speed).

The CVF pullies I have on my non-A/C GTO are both 6.2", (crank and WP), for a 1:1 ratio, (or 100%). The High-flow that CVF offers is the same 6.2 wp pulley with a 8" crank, for a 129% overdrive. I'm going to try a 8" wp pulley to underdrive it to 77.5% of crank speed. My engine idles at 1000, (manual trans), so the water pump will still be turning at 775 rpm. I run a flex fan with no cooling issues, but I don't like the fact that the fan is turning 6000 rpm at my shift points. By underdriving it 77.5%, at my 6000 rpm shift point, the fan will now be turning only 4650 rpm. Less stress on the fan blades and less drag.

[JSchmitz]

You need a severe duty fan and clutch. Going to be hard to keep that thing col with A/C. '64's just don't have much room for a big radiator.

[64speed]

its an airflow issue. At 220 my dash light comes on. As soon as I start moving I drop to 185 within 2 miles. I am gonna have to get an electric fan.

[64speed]

I know yall are gonna think I am crazy but this mechanical fan really does not move any air. I expected a roar too and I dont have one. And before anyone asks yeah its on right LOL

[JSchmitz]

Originally Posted by 64speed

I know yall are gonna think I am crazy but this mechanical fan really does not move any air. I expected a roar too and I dont have one. And before anyone asks yeah its on right LOL

What clutch do you have. I have a heavy duty and a severe duty for my car. Significant difference between the two. NOTHING will pull more air than a severe duty clutch fan in my opinion.

[64speed]

Look at this POS I started with

[64speed]

Originally Posted by 64speed

Look at this POS I started with

So before I take the plunge does anyone have anything against electric fans?

[misterp266]

Originally Posted by 64speed

Look at this POS I started with

Ya, but did it overheat?

[64speed]

I have tried all of the above. Mechanical now. I am sending it back and putting electric

[grivera]

Originally Posted by 64speed

I have tried all of the above. Mechanical now. I am sending it back and putting electric

Make sure you choose an electric that moves enough cfm - like a Mark VII, otherwise you'll likely be worse off than now. Also it will have to be a type with a shroud not the sheet metal that's attached to radiator - those block airflow. Lots of info on this in cooling section.