[64speed]

The mechanical fan helped, and you cant hear it over the exhaust so that is not a concern but it didnt stop it it just made it take and incredibly long time to get up to 210. I didnt try to see if it would go past that, I shut it off. Any other remedies yall have had success with? I am gonna turn the idle up a little bit and mess with the timing curve but I think I am gonna have to do the core support mod and get the bigger radiator. It will not even really heat up if the AC is not on. Runs around 170. will the AC really make 50 degrees difference?

[max 93]

Can you change pulley sizes? I fixed a warm running engine by changing from standard pulleys to ac pulleys

[grivera]

Dave - I asked above- does it have vacuum advance and if so how much and is it manifold source?

[64speed]

It is full vacuum. It ran better that way at cruise it seemed. I am going on vacation for a week next week but when I get back I am gonna really dive into it. I have a sheet from MSD about which springs do which so I am gonna setup my curve and see what happens

[64speed]

Originally Posted by max 93

Can you change pulley sizes? I fixed a warm running engine by changing from standard pulleys to ac pulleys

I have the CVF AC pulley. Is anyone running the Edelbrock Victor Pump?

[68WarDog]

Originally Posted by 64speed

I have the CVF AC pulley. Is anyone running the Edelbrock Victor Pump?

I too am running the CVF pulleys, but in the kit they sent me it had the 6" underdrive crank pulley, and a 5.5 inch wp pulley. I removed the 6" crank pulley and replaced it with a 8" pulley.. Those 6" crank pulley are not intended for 455 that may see alot of traffic idling time. You may want to modify the clutch spring as referenced by grivera. It was worth about a 10 degree drop in heavy 90* idling traffic here in NC.

[bluebandit]

Speed up your water pump. You can blow a zillion cfm thru the radiator and it wont do squat if the water aint running thru it

[JSchmitz]

I had CVF v-belt pullies. I ordered them with the large crank pulley. IDK why they would make the small one standard.

[64speed]

I just called. I have the right pulleys so thats a bust.

[64speed]

Is it worth changing from the 160 thermostat?

[grivera]

Originally Posted by 64speed

Is it worth changing from the 160 thermostat?

The thermostat will only control minimum temperature- if your cooling system can’t keep up a 180 won’t help.

Re: your crank pulley it would be prudent to measure just in case.

[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

[ZeGermanHam]

Originally Posted by 64speed

Is anyone running the Edelbrock Victor Pump?

Yes, I installed that pump in my '66 a year or two before restoration began and it will be going back in. My brother also has it in his '74 GTO with 461ci. It's a quality unit, but I can't speak to whether it pumps more coolant than the water pump you already have. There are too many differences between my brother's car and your car to be comparable, but I think his 462ci rarely gets above 190F, even in 90F humid weather in the Midwest.

[68WarDog]

Originally Posted by JSchmitz

I had CVF v-belt pullies. I ordered them with the large crank pulley. IDK why they would make the small one standard.

Possibly the opportunity to "up sale"? I checked the site and the 6" crank pulley remains part of the standard Pontiac kit. . I also ordered a second kit about 3 months ago and it too came with the 6" with no option to exchange in the kit.An 8" will be installed before the engine goes in service.

[tom s]

too small bottom and too big water pump IMO.Tom

[JSchmitz]

Originally Posted by 68WarDog

Possibly the opportunity to "up sale"? I checked the site and the 6" crank pulley remains part of the standard Pontiac kit. . I also ordered a second kit about 3 months ago and it too came with the 6" with no option to exchange in the kit.An 8" will be installed before the engine goes in service.

Could be. I assume most of these pullies will go on street cars. doesn't make sense to underdrive these vs. factory. One of my best cooling improvements was switching to an A/C water pump pulley set.

[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.