[64speed]

I replaced my thermostat from a 180 to a 160 because I am in SC and it’s about to be 93 degrees average haha. I pulled the sacrificial anode from the radiator, let it drain then squeezed the radiator hoses until no more water came out. After changing the thermostat I put two gallons of antifreeze and two gallons of water and it won’t take anymore. Sure as hell seemed like more than that came out. When driving it hovered right around 160 but while idling it SLOWLY creeps up to 200. Doesn’t seem to go any if much past that but I just wondered if that was enough coolant? Any more suggestions? I am running the 15 inch fan cause it is all that will fit in the Tempest shroud. Fan is half in but could probably accept a 1/2 spacer if it would help. Gaps around shroud are sealed with AC foam

[Sirrotica]

Unless you drained the block, (which you didn't) there's about a gallon still in there. The block is drained by removing the 2 pipe plugs on either side just above the oil pan rail. Usually a hex head, if they are original plugs.

From my years of experience, just draining the radiator will remove approximately 3.5 gallons, which is what you have already eluded to it took to refill it. Of course different engines, and radiator combinations are different amounts.

You can use an antifreeze tester to check how much coolant to water ratio. Around 40 below, is usually nearly 50/50 mix.

[25stevem]

Oh my God!!!!

[Murf]

Not sure what you’re asking. You filled it with 50/50 it sounds like. When it cools is the level an inch or two from the top? If so, it should be fine. If not, add some. Not a big deal realty, full is full.

Temp creap standing still, you could probably use more air flow but 200 isn’t bad.

I’m confused on your fan size. I have a 65 with I think a 17 inch 7 blade I got from Ames. It fits the shroud I got from Ames also. 15 seems kinda small but IDK.

Murf

[Half-Inch Stud]

Thinking Temp creep-up at idle is "normal" for a Pontiac withc an insufficient Cooling fan at Idle.

I've learned that the Cooling Fan is most needed at idle, slow crawl in parades and bumper-bumper traffic.

[Tom Vaught]

You could have gotten more more fluid out of the block/heads by simple jacking up the rear of the car up 12 inches (placing the jack under the rear housing).

If the fan is a stock fan, without the "water pump mod", you may not achieve best cooling, especially at idle.
Did you do the "water pump mod" that has been posted about many times on the board?

Lastly, is the radiator a original radiator or a re-core piece?

As was mentioned, if you did not remove water from the block there is little chance of adding water to the block
without removing some initially.

Tom V.

[grivera]

Originally Posted by 64speed

I replaced my thermostat from a 180 to a 160 because I am in SC and it’s about to be 93 degrees average haha. I pulled the sacrificial anode from the radiator, let it drain then squeezed the radiator hoses until no more water came out. After changing the thermostat I put two gallons of antifreeze and two gallons of water and it won’t take anymore. Sure as hell seemed like more than that came out. When driving it hovered right around 160 but while idling it SLOWLY creeps up to 200. Doesn’t seem to go any if much past that but I just wondered if that was enough coolant? Any more suggestions? I am running the 15 inch fan cause it is all that will fit in the Tempest shroud. Fan is half in but could probably accept a 1/2 spacer if it would help. Gaps around shroud are sealed with AC foam

Are you running the AC in the scenario you described above? If not, with the AC on that condenser will throw some heat at the radiator and will be the better test of the cooling system. Also, for future reference if using the antifreeze concentrate it is best to premix it 50/50 with distilled water prior to pouring in to ensure an even mixture rather than pouring in a gallon of water separate from anti freeze.

[Formulajones]

A 15" fan?? Holy cow that's small for a tempest, even an early tempest.

The V8 Monza's I used to play with had a factory 16" fan with a very small radiator, and those are pretty small cars compared to an early tempest.

I just looked at our 69 camaro, which is smaller than your tempest. The radiator is only 22" wide and it has it's original 18" clutch fan inside the stock shroud.

I'm going to guess your shroud is limiting your fan size by your description. I suppose 15" can be made to work if that's what you're stuck with. So it might come down to your pulley ratios if hot idling is your issue. You aren't moving enough air and/or coolant in an idle situation. A smaller water pump pulley may help. That will move coolant a bit faster and also speed up the fan.

[Formulajones]

Something else you can try if you haven't already....

Since most of our driving is stop and go around town and a lot of idling, I've found that the cars tend to like manifold vacuum for vacuum advance rather than ported.

As you may know, ported only works when the throttle blades are cracked open, so in idle situations the vacuum advance is inactive. I've found our cars tend to run maybe 10-15 degrees warmer in those idle situations with ported vacuum advance. It was never hot, just warmer than when cruising with the throttle open.

With manifold vacuum advance I find the temps are very steady at cruise and at idle, In fact some of them actually idle cooler than they cruise. Which is a good thing here in the Arizona summer, especially when you get caught in a traffic jamb. So I tend to leave the vacuum advance on a manifold source.

Anyway, it's an easy test just moving a vacuum hose, see if it works for you or not.

[64speed]

I have the smaller radiator that came with the base 326 cars hence the smaller fan, I thought it was 15 inch but it’s not it’s a little larger. Car hasn’t run hot on me yet but I have replaced it with a cold case designed for the non AC non GTO core support.

[Formulajones]

Those Cold Case radiators are pretty nice.

[64speed]

Originally Posted by 25stevem

Oh my God!!!!

Oh my god what? I asked how much should I expect to put in? It wasn’t an overheating question

[64speed]

I filled it with concentrate and distilled water