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  1. #1
    Join Date
    Aug 2006
    Location
    Millington TN
    Posts
    204

    Default Anti-Freeze Protection Levels

    The new Raptor Engines are equipped with what is commonly referred to as a "half closed cooling system". This means that the engine block (including the heater) is cooled by anti-freeze and the exhaust manifolds are cooled by raw water. The anti-freeze that we use is propylene glycol based anti-freeze. Following is a service article that I wrote regarding anti-freeze protection levels. To test the concentration of the anti-freeze in your Raptor engine you will need a tool called a refractometer. The "floating ball" type testers are not recommended. Refractometers are a bit more expensive but they will measure ethylene glycol, propylene glycol and battery acid concentrations and on top of that are a lot cooler than floating ball testers. Here is a good excuse for you "tool junkies" out there to buy something to impress your friends with!

    A normal 50:50 mix of propylene glycol provides a protection level that will allow an engine to operate at -26°F (-32°C). That means that no ice crystals will form in the coolant till the temperature drops below -26°F (-32°C). This is referred to as the freezing point of the anti-freeze.

    At any ratio of 35:65 (35%) or higher, propylene glycol provides additional protection to lower than -50°F (-46°C). This protection level is referred to as the burst point. The burst point is the point where the crystals in the coolant are able to expand and cause damage to the cooling system. In other words, it is OK for the coolant in the cooling system of an engine to turn to slush as long as the engine is just being stored and will not be expected to operate till the weather gets warmer.

    Since it is pretty unrealistic to think that a customer will actually be using their boat at -26°F, the bursting point becomes the more important value to pay attention to. Following is a chart showing the anti-freeze ratio and the corresponding freezing point and burst point.

    Ratio Freezing Point Bursting Point
    50/50 (50%) -26°F (-32°C) -50°F (-46°C)
    40/60 (40%) -5°F (-20°C) -50°F (-46°C)
    30/70 (30%) +10°F (-12°C) -20°F (-29°C)
    20/80 (20%) +20°F (-6°C) +10°F (-12°C)

    A 40/60 (40%) ratio provides adequate burst protection for most of us. The 50/50 (50%) mix historically has been the recommended concentration because of the convenience being able to determine how much anti-freeze and water you need to use for a given system.
    Larry Engelbert
    Indmar Marine Engines
    "Power to the Sport"

  2. #2
    Join Date
    Aug 2009
    Location
    Montana
    Posts
    3,062

    Default

    As Always - very useful information in your posts Larry!!
    This forum is lucky to have you.............

    2007 Moomba Outback - going, going, GONE
    2015 "NOT A MOOMBA"

    Why Not? Play Hard! Get wet

  3. #3
    Join Date
    Sep 2016
    Location
    Columbus, GA
    Posts
    11

    Default

    Hello,

    i am new here and a new Moomba owner. I have a 2016 Mojo surf edition and live in western Georgia. we have mostly mild winters here and the temp rarely goes below 32 deg F. I plan on using the boat throughout the winter. Do i need to winterize it since it's a "half" closed-system, or, is there anything else i should worry about?

    thanks

  4. #4
    Join Date
    Mar 2003
    Location
    Springfield Missouri
    Posts
    3,391

    Default

    Quote Originally Posted by Mc_Mojo View Post
    Hello,

    i am new here and a new Moomba owner. I have a 2016 Mojo surf edition and live in western Georgia. we have mostly mild winters here and the temp rarely goes below 32 deg F. I plan on using the boat throughout the winter. Do i need to winterize it since it's a "half" closed-system, or, is there anything else i should worry about?

    thanks
    The manifolds hold water so I would recommend draining them. I would look for a replacement for the manifold drain plugs that are valved for convenience of draining each time.
    1998 Mobius
    310 HP PCM
    SOLD

  5. #5
    Join Date
    May 2013
    Location
    Vancouver WA
    Posts
    5,019

    Default

    Quote Originally Posted by Mc_Mojo View Post
    Hello,

    i am new here and a new Moomba owner. I have a 2016 Mojo surf edition and live in western Georgia. we have mostly mild winters here and the temp rarely goes below 32 deg F. I plan on using the boat throughout the winter. Do i need to winterize it since it's a "half" closed-system, or, is there anything else i should worry about?

    thanks
    If it was me and the temp wasn't going to go below freezing, I wouldn't sweat it. If it was going to drop below freezing, I'd throw an incandescent shop light into the engine compartment. There have been many threads showing that it takes more than a quick dip below 32 degrees to cause any potential for damage.
    2008 Moomba Mobius XLV. Monster Cargo Bimini, WS Rev 410's, Polk Cabins, 3 Infinity Subs, PPI amps, WS420, Exile BT, upgraded ballast pumps, up to 3,500+ pounds of ballast, Blue LED's...
    1992 Supra Sunsport. **SOLD** 2k pounds ballast, Surf System, Blue LED's everywhere, decent audio system.
    Tow Rig: 2013 F150 Ecoboost FX4 (wife's rig) Other money pits include:1998 BMW M3 Cabriolet, 2009 Audic A6 Avant 3.0T, 2005 Kawasaki ZX-6R 636.
    www.TraysonsToybox.com

  6. #6
    Join Date
    Aug 2006
    Location
    Millington TN
    Posts
    204

    Default

    Quote Originally Posted by Mc_Mojo View Post
    Hello,

    i am new here and a new Moomba owner. I have a 2016 Mojo surf edition and live in western Georgia. we have mostly mild winters here and the temp rarely goes below 32 deg F. I plan on using the boat throughout the winter. Do i need to winterize it since it's a "half" closed-system, or, is there anything else i should worry about?

    thanks
    If there is a chance of going below freezing
    , I would not take a chance. There are only 4 drain points on the engine ... the line that goes from the raw water pump to the heat exchanger, the heat exchanger itself, the exhaust manifold crossover and the drain plug on the v-drive anode. The light bulb in the bilge may work ... till the power goes out.
    Larry Engelbert
    Indmar Marine Engines
    "Power to the Sport"

  7. #7
    Join Date
    Sep 2016
    Location
    Columbus, GA
    Posts
    11

    Default

    Thanks for all the replies; if it gets cold enough to freeze, I'll bring the boat into our garage for a couple of days;

    Larry; i'll check those locations to see if i can find the drain ports; so if i drain those locations, the rest of the engine will be fine?

    Thanks again!

    Derek

  8. #8
    Join Date
    May 2007
    Location
    Richmond, VA
    Posts
    2,102

    Default

    Quote Originally Posted by Engine Nut View Post
    The new Raptor Engines are equipped with what is commonly referred to as a "half closed cooling system". This means that the engine block (including the heater) is cooled by anti-freeze and the exhaust manifolds are cooled by raw water. The anti-freeze that we use is propylene glycol based anti-freeze. Following is a service article that I wrote regarding anti-freeze protection levels. To test the concentration of the anti-freeze in your Raptor engine you will need a tool called a refractometer. The "floating ball" type testers are not recommended. Refractometers are a bit more expensive but they will measure ethylene glycol, propylene glycol and battery acid concentrations and on top of that are a lot cooler than floating ball testers. Here is a good excuse for you "tool junkies" out there to buy something to impress your friends with!

    A normal 50:50 mix of propylene glycol provides a protection level that will allow an engine to operate at -26°F (-32°C). That means that no ice crystals will form in the coolant till the temperature drops below -26°F (-32°C). This is referred to as the freezing point of the anti-freeze.

    At any ratio of 35:65 (35%) or higher, propylene glycol provides additional protection to lower than -50°F (-46°C). This protection level is referred to as the burst point. The burst point is the point where the crystals in the coolant are able to expand and cause damage to the cooling system. In other words, it is OK for the coolant in the cooling system of an engine to turn to slush as long as the engine is just being stored and will not be expected to operate till the weather gets warmer.

    Since it is pretty unrealistic to think that a customer will actually be using their boat at -26°F, the bursting point becomes the more important value to pay attention to. Following is a chart showing the anti-freeze ratio and the corresponding freezing point and burst point.

    Ratio Freezing Point Bursting Point
    50/50 (50%) -26°F (-32°C) -50°F (-46°C)
    40/60 (40%) -5°F (-20°C) -50°F (-46°C)
    30/70 (30%) +10°F (-12°C) -20°F (-29°C)
    20/80 (20%) +20°F (-6°C) +10°F (-12°C)

    A 40/60 (40%) ratio provides adequate burst protection for most of us. The 50/50 (50%) mix historically has been the recommended concentration because of the convenience being able to determine how much anti-freeze and water you need to use for a given system.
    Larry - What is the benefit of a half closed cooling system? Longer engine life? Lower production cost? Ease of operation? Also, does the system operate with a radiator, like an automobile engine? Curious. All I have ever owned were open, fresh water cooling systems. Thanks. - Stuart
    2007 Outback - SOLD June 2016
    2012 RAM Crew Cab
    2015 Subaru Forester
    Stuart

    "When you first start out with something new, you're always a little uptight." - Don Rickles

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