Running straight coolant

[runnergeorge]

Hey everyone! I got a 75 c10 350/350 stock except an edelbrock 650 carb and a performer intake that I believe is warped. My current question is, does anyone have an opinion about running straight coolant? I知 in the Sacramento CA area and a reputable auto parts store suggested to run straight coolant instead of mixture. The reason I知 asking is because when I removed the intake I saw some slight rust in the water channel going from the block to the intake and I thought running straight coolant would help stop more rust from happening. I知 completely new to the older truck game and I知 learning as I go (and by making mistakes). Thanks everyone!

[bd]

Use "50/50 premix" ethylene glycol (green) coolant or mix full strength ethylene glycol coolant with 50% to 40% distilled water for a 50/50 to 60/40 coolant/water mix.  Straight coolant has a high boiling point (~388ｰ F at sea level) but doesn't cool as well as coolant/water mix, while it exhibits a surprisingly high freezing point (~10ｰ F).  In comparison, an optimized 60/40 mix boils at ~232ｰ F at sea level and freezes at ~-63ｰ F.  The effect of a 60/40 mix cooling system pressurized to 15 PSI boosts the boiling point of the coolant by roughly 38ｰ F to ~270ｰ F.  Regardless of the coolant/water ratio you employ, flush and replace the coolant approximately every two years or 50,000 miles to restore exhausted oxidation inhibitors that are part of the coolant chemistry.

[runnergeorge]

On the note of straight coolant, I have noticed that once the engine is warm it gets almost too hot real quick. I will drain some and replace it with about 40-50 percent distilled water. I知 guessing the distilled water is better since it doesn稚 have other contaminants in it?

[MIKE S]

BD is correct. Antifreeze is a poor conductor of heat. It will not absorb the heat from the engine efficiently nor will it give off its heat to the radiator. I once put way to much antifreeze into a pickup  as I was in a hurry and noticed the engine was running very hot while pulling a load. You could here the fan clutch cycle from a whisper to a roar but at a much higher temp on the gauge than before. there was not enough heat coming off the radiator to activate the bimetallic spring on the fan clutch.  I drained all coolant out of the radiator and block and refilled with 50/50 water and coolant and the temp and fan clutch operation returned to normal.

[bd]

On the note of straight coolant, I have noticed that once the engine is warm it gets almost too hot real quick. ... I知 guessing the distilled water is better since it doesn稚 have other contaminants in it?

Distilled water is preferred because it doesn't contain chemically reactive salts.  Make sure that the radiator is completely full of fluid after it has cycled through one complete heating and cooling cycle.  Air in the cooling system, besides promoting rust, can invite erratic thermostat behavior and engine overheating.

[runnergeorge]

All of that is definitely grate to know! Like I said I知 learning as I go so I知 learning what not to do as I go and having to go back and fixing things. Thanks everyone. I値l be draining the coolant and adding distilled water this weekend!

[VileZambonie]

Don't take advice from the idiot at the auto parts store. If he knew what he was doing, he'd be a mechanic.