[64speed]

My vision is not good enough to see the timing mark so I have to get help but turning the cap a little at a time produces a crappy running engine other than exactly where it is. It is slow to creep like I said but it creeps. Turning on the heater instantly drops it 15/20 degrees from wherever it is and holds it there. I am getting a bigger mechanical fan cause I did the paper test and it will hold a sheet against the radiator but not with the force I feel it should.

[grivera]

Originally Posted by 64speed

It’s at 15

15 mechanical. Add 10 via manifold vacuum and see if it cools down.

[64speed]

Ordered the Derale 17 inch racing fan that has 5 stars on Summit. Will put it on soon and report back

[NeighborsComplaint]

Originally Posted by 64speed

Ordered the Derale 17 inch racing fan that has 5 stars on Summit. Will put it on soon and report back

I ran one of their stainless blade flex fans that came with the car. It moved a lot of air but was really loud. It made the car sound like the local garbage truck at slow speeds but did keep the car cool. I went to a stock style clutch fan and the car runs a touch hotter but much quieter.

[grivera]

Originally Posted by 64speed

Thank you for the modified fan clutch. I have a Cold Case radiator, fan shroud, biggest fan that will fit in it (17 inch) and a Hayden severe duty clutch. I dont know if it would actually overheat or not, I just dont want to find out at the worst time.

Originally Posted by 64speed

Ordered the Derale 17 inch racing fan that has 5 stars on Summit. Will put it on soon and report back

Dave - I thought you already had a 17" fan in it?

[64speed]

It’s the Tempest fan. It’s 16, I thought it was 17

[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

[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.

[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.

[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

[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.

[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.

[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]

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.