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1985VK

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The pressure in a V6 system is very high regardless I wouldn't advise increasing it, if anything it can be dropped a tad to help with coolant leaking problems that the V6 is notorious for.

How high is very high?
 

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More info:

Our coolant’s boiling temperature of 223° F (106° C) is when it is under 1 psi, which is why most cooling systems are designed to operate at 15 or 18 psi.

As the coolant heats up, it begins to expand and create additional pressure. By allowing that pressure to increase, the boiling point of the coolant is increased to around 257° F (125° C) at 15 psi. This gives us better performance from our cooling system as it can absorb additional heat from the engine without boiling.

https://www.cgj.com/2013/05/14/how-does-a-radiator-pressure-cap-work/

This article is suggesting using a pressure cap with a higher pressure rating to increase cooling system performance ... as long as you don't blow a hole in the cooling system etc ...

On an old car with a shabby cooling system using a higher pressure rad cap may not be a good idea ...

The V6 runs at 21psi. It's fairly obvious that raising the pressure in the system does a lot more than adding the anti-freeze and then you need to consider the ability of the anti-freeze to remove heat Vs just plain water.

IMHO anti-freeze is just not required in warm climates. Use the corrosion inhibitor with water and save your money for something else.
 

1985VK

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That's a major statement on coolant and cooling system ideology! To run a cooling system on type B corrosion inhibitor based on climate and disregard the hype ...
 
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Oh my....we are talking 20+yo engines that prob ran 1/2 their life with incorrect ratio of coolant.....shiiiish dont sweat it just put in what you have..hell Ive seen every thing from putrid water from a muddy puddle to pure 100% concentrate used......main thing is keep the fluid levels up and keep an eye on it...
 

1985VK

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This is a great thread and i thought about the subject of cooling last night. What would be the best type B "coolant" ie corrosion inhibitor on the market? Is cavitation and lubrication really that important? How more cool can you run using a higher pressure rad cap without risking a leak especially on an older cooling system etc?
 

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I'd be wary of running higher coolant system pressure on any gen 1 or 2 Commodores as the weak point will be the copper/brass heat exchanger for the HVAC system under the dash. It's a PITA if that starts to leak.
 

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Its a trade off on older systems ... even using the rated cap has a risk of a leak if the cooling system has some age on it ... apparently some people use a lower psi cap on older commies but that can also mean running hotter ...
 

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A lower psi cap won't increase the running temp, it just lowers the boiling point.
 

1985VK

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A lower psi cap won't increase the running temp, it just lowers the boiling point.

I don't understand the difference? I assumed raising the boiling point would have a net effect of running cooler but that is not so?
 

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Nope, increased pressure = higher boiling point and visa versa...
 
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