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Whats the mix for radiator after flushing it???

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Bone85K5, Apr 16, 2003.

  1. Bone85K5

    Bone85K5 1/2 ton status

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    Its a 350 witha carb by the way..any ideas what do u guys run with??
     
  2. sled_dog

    sled_dog 1 ton status

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    uh I just run 50 50
     
  3. dyeager535

    dyeager535 1 ton status Premium Member

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    I run 30/70 (30 antifreeze/70 water)

    The more water you run, the better the cooling will be, but won't protect to as low a temperature as a 50/50 mix. The bottle SHOULD show a chart of the freezing point based on ambient temp/antifreeze water mix ratio though.

    50/50 is safe, but not really necessary in warmer climates, and as I said, isn't quite as good at cooling as the 30/70 mix.
     
  4. heavy4x4

    heavy4x4 1/2 ton status

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    I think you may be getting your reasoning messed up a little.

    Anti-freeze (also known as coolant) does what both of its names say. It raises the bowling point of the water/coolant mixture and lowers the freezing point. For instance, if you were running straight water, your "coolant" would boil when your engine reaches 212 degrees Fahrenheit. And, if your "coolant" was just water, it would freeze when the temp hits 32 degrees (I'm assuming we all know that). Boiling coolant and frozen coolant are not good /forums/images/graemlins/tongue.gif. So, that's why we use "Anti-freeze."
    There is a delicate balance of coolant-to-antifreeze mix that needs to be reached. That's why most people run a 50/50. There needs to be enough anti-freeze in the mix to lower the freezing point sufficiently enough. But, too high of a concentration of anti-freeze will lead to poor cooling and increased corrosion.
    There is more to this and I'm not going to go into all of it, but another little tidbit is that in order to raise the boiling point even higher than the anitfreeze does, the system is under pressure (thus the 15psi/16psi radiator caps).
     
  5. rick88blaze

    rick88blaze 1/2 ton status

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    50/50 in every vehicle i've ever owned, and i've never had a problem with freezing or boil over.
     
  6. 90K5

    90K5 1/2 ton status

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    I usually buy a gallon of antifreeze and a few gallons of distilled water...pour all the antifreeze in and then top it off till full with water. its cheaper that way, and since the cooling system usually holds 2 or a little more gallons, usually works out to 50/50 - 30/70
     
  7. dyeager535

    dyeager535 1 ton status Premium Member

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    You might want to read a bottle of antifreeze. Nowhere on there will it say it raises the boiling point appreciably. (last I checked) You'll also notice that it tells you the minimum and maximum ratios to run, which provide *freze protection* down to XX degrees based on that ratio. Antifreeze (or an antifreeze mix) cannot absorb heat like water can, thats why lower ratios of antifreeze work better in warmer climates.

    *Pressure* is what (almost) entirely raises the boiling point of water in an automotive system. It's not called "anti-boil" is it? /forums/images/graemlins/smile.gif

    FWIW some racing apps (NASCAR I think) run like 20+ PSI systems.

    Based on what they are saying on some of the products web pages (peak for instance) they cite a VERY high boilover temp with antifreeze. However, I'm gonna hold out slightly, they don't indicate how much of that is from pressure.

    clicky antifreeze link Doesn't show nearly the boiling temp increase with antifreeze that the manufacturers claim...makes me believe the manufacturers numbers are measured while under pressure.
     
  8. HarryH3

    HarryH3 1 ton status Author

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    [ QUOTE ]
    FWIW some racing apps (NASCAR I think) run like 20+ PSI systems.

    [/ QUOTE ]
    Most racing bodies also don't allow antifreeze to be used. It makes the track too slippery if it should leak out. /forums/images/graemlins/eek.gif

    Also, I think the point you are trying to make is that water is a better thermal conductor than ethylene glycol. It will carry heat away from the block faster and transfer it to the raditor core faster. /forums/images/graemlins/cool.gif So if you live and drive where the weather never gets below 30 degrees, then having "antifreeze protection" that's good to minus 34 degrees isn't just a waste of money, it can contribute to a marginal cooling system overheating.
     
  9. wrathORC

    wrathORC 1/2 ton status

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    Antifreeze has come a long way since the 70s and even then it was good to 260° and -10° even though it had to be changed every 2 years.

    A 50/50 mix has a specific heat of about half what plain-jane water does. That means it gets rid of heat about half as good as plain water but the nifty thing about the mixture is that it doesn't boil as easily as water. The surfaces the mixture is presented can exceed 212°. The pressure of the system (usually 14-16psi) helps keep coolant from boiling as well. This is why so many people get away with running no antifreeze in the south. I haven't had chemistry in 3 years but I think 10psi increase on water was worth 20some degrees increase in boiling point.

    I'm no Chemical Engineer (in fact I got a C in General Chemistry here at MTU--the class average), but I believe antifreeze works by making water more resistant to boiling by bonding with it and increasing ions (pH of antifreeze is 8-10 or something, I forget). However, the hillbilly in me says not to go over 50/50 because of the heat carrying ability (specific heat) goes down a lot if you mix a lot of antifreeze in versus the temperature protection.

    I think 50/50 is ideal. And get rid of those fscking 6-7psi radiator caps. The previous owner (moron) put a 6psi radiator cap on my truck and a 2 core radiator even though my truck called for a 3 core and a 14-16psi cap.


    [​IMG]
     
  10. heavy4x4

    heavy4x4 1/2 ton status

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    [ QUOTE ]
    You might want to read a bottle of antifreeze. Nowhere on there will it say it raises the boiling point appreciably. (last I checked)

    [/ QUOTE ]
    I didn't say a bottle would state that...just simply stating the fact that ethylene glycol does exactly that.
    Taken directly from the sight you linked:
    [ QUOTE ]
    By adding ethylene glycol to water, the boiling and freezing points are improved significantly.

    [/ QUOTE ]
    Don't know what's so hard to understand about that. /forums/images/graemlins/deal.gif

    ---------------
    Here's what you said:
    [ QUOTE ]
    Antifreeze (or an antifreeze mix) cannot absorb heat like water can, thats why lower ratios of antifreeze work better in warmer climates.

    [/ QUOTE ]
    Here's what I said:
    [ QUOTE ]
    ...too high of a concentration of anti-freeze will lead to poor cooling

    [/ QUOTE ]
    Hmmm...don't see much of an argument in what we're saying there /forums/images/graemlins/smirk.gif
     
  11. dyeager535

    dyeager535 1 ton status Premium Member

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    Well there seems to (still) be a huge variation in the manufacturers claims, and the claims of non-antifreeze companies.

    If people would actually look at the numbers on the link I posted previously, they will see that boiling point claimed there with ethylene glycol (can't quite make out the ingredients on the prestone bottle picture, something glycol) is a HELL of a lot lower than what prestone is claiming. If you add the increased boiling point of water under pressure (approx 45* in a vehicle) that would be what that Prestone bottle claims.

    That page I linked isn't the only one showing an antifreeze mixture is NOT where the boilover protection comes from.

    Whats that ASTM spec number on the bottle? I'll be more than happy to see if I can't find out info on that spec, but I'd be willing to bet that the specification is measured under pressure.

    If I'm wrong I'll admit it, but since there is an obvious disparity between the antifreeze companies claims and non-antifreeze company claims, I'm certainly not going to agree that the antifreeze is what raises the boiling point so much. If it were, why are we still running pressurized systems, when engine damage will occur right around where the antifreeze bottle rated temp max is?
     
  12. heavy4x4

    heavy4x4 1/2 ton status

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    I guess I should have made this more clear. I wasn't trying to sound like I was accusing you of being wrong. Sorry if it came across that way.
    Yes, I agree that water dissipates heat better than ethylene glycol. Therefore, more water in the system than antifreeze should do a better job of cooling. I was just simply stating that it is helpful to have a decent amount of antifreeze in there because it does raise the boiling point a bit. I was unaware of the fact that the pressure contributes so much more to the higher boiling point than the addition of ethylene glycol. Thanks for the info. I consider myself further educated.
     
  13. wrathORC

    wrathORC 1/2 ton status

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    Antifreeze is ANTI-freeze. It isn't there to increase the boiling point. There's a reason why cooling systems since the dawn of time have been pressurized. It's to keep it from boiling and getting full of air. Vapor is a pretty shitty way of heat exchange. It also works as a good way to keep the maximum amount of coolant in the system (by when cooling suck coolant out of the reservoir).

    Ethylene glycol also does a lot to stabilize water. That means it foams less. The entire cooling system is pretty turbulent and is ripe for creating foam. Add to that and the fact that it is real easy for coolant to boil near the exhaust valves and things get real crazy.

    If someone knew the exact formula for figuring out how much the boiling point increase for regular water for each increase in psi and then the same thing for 50/50 mix you'd probably find that 50/50 mix has a steeper curve.

    EDIT:
    Doh. I forgot to mention it says on the antifreeze bottle that the protection is based on a 15lb pressurized system.

    Get your ATSMs here:
    http://www.prestone.com/tips/page7.htm
     
  14. dyeager535

    dyeager535 1 ton status Premium Member

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    Here ya go:
    http://www.valvoline-technology.com/data/valv/prodinfo.nsf/064d8b901e00e75f85256b140058985e/85256ae300727d2b85256727004968f8/$FILE/2792%20Heavy%20Duty%20Precharged.pdf

    Notice the pressure?

    http://www.lathingstodo.com/AvenValk/techinfo/antifreeze.htm

    Theres another one. Some manufacturers online "admit" the numbers are 15PSI, others don't mention it at all.

    I have to doubt that some name brand antifreeze is horrible at boil over protection, yet magically others are 60*+ better than them.

    Since 15PSI adds approx. 45* to waters boiling point, a claimed boiling point of 275* minus 45* for 15PSI, and about 20* for the antifreeze addition, equals 212*.

    Sounds more than a little suspicious to me if not every manufacturer is meeting similar specifications.
     
  15. dyeager535

    dyeager535 1 ton status Premium Member

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    Actually, I found the EPA reg online covering the boiling test for antifreeze (actually all kinds of chemicals/compounds) but it's not psi/fahrenheit, (millibars and celsius as I recall) and since I don't know the formula's to convert it, I didn't feel it would add anything to our discussion.
     
  16. m j

    m j 1/2 ton status

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    in a perfect world we would run distilled water with a surfactant/lubricant in the warm weather, bonus cooling ability
    then switch to antifreeze for the winter

    if your ride is trail only I would go the first route if possible
    ethylene or polypropolene glycols are not envirnmentally friendly things
     
  17. wrathORC

    wrathORC 1/2 ton status

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    Last Thursday I sent an email to Prestone asking them what the boilin point of their antifreeze was mixed 50/50 with distilled water at 1 atmosphere (14.7psi). That means no pressurized system (exposed to the outside atmosphere at sea level). Their reply was 225 degrees Fahrenheit.
     
  18. 77JMY

    77JMY Registered Member

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    TO BE ON THE SAFE SIDE RUN 50/50 THATS WHAT THE MANUFACTURERS RECOMMEND. ON TOP OF ALL THIS WONERFUL INFORMATION I WOULD HIGHLY RECOMMEND RUNNING DEXCOOL AND NOT HAVE TO WORRY ABOUT IT FOR 150,000 MILES OR 5 YEARS.
    GREEN ANTI-FREEZE HAS A SHELF LIFE OF 18 MONTHS NEW OR IN USE THEN YOUR SCA'S START DROPPING OUT, YOU DON'T GET THAT WITH DEXCOOL. ALSO COOLANT ISN'T AS HARMFULL TO THE ENVIRONMENT AS YOU THINK.
     
  19. Miller

    Miller Registered Member

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    interesting /forums/images/graemlins/wink.gif
     
  20. wrathORC

    wrathORC 1/2 ton status

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    Dexcool isn't all that it's cracked up to be.

    Coolant needs to be changed when it gets dirty. This can be anywhere from 2-4 years. Enameled blocks tend to keep the coolant clean longer. More important is keeping the right mixture. This can be checked with those coolant testers you get with the little foam balls or the dial indicator one.

    I'm no expert on brake fluid... but if you want to start telling people to change antifreeze more frequently than necessary you need to tell them to change ALL their brake fluid every 18-24 months. Brake fluid degrades much more quickly than coolant. In essence, after a year, a brake system usually grabs between 2% and 6% water from the environment. That means it's pretty common to lose 80°F on the boiling point even with relatively dry fluid. I believe DOT 3 rated fluid is allowed to lose something like 110° for 3% water gain. If you want to tell someone to upgrade to something, tell them to use DOT 5 fluid. It's not nearly as corrosive and it doesn't absorb moisture nearly as much.
     

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