specific coolant rather than water?
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T
tanuie
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Hi I if you go on to e bay and look for waterless coolant it will tell you all about it, it seems rather expensive to me.
wongl
MB Enthusiast
What's wrong with the coolant from Merecedes?
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Just add distilled water with it.
Marku
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Just finished rebuilding the engine of the 450 and intend to use waterless coolant in it. Yes it's really expensive and will cost about £64 to fill but it I think that it will be kinder to the 43 year old engine. It has a higher boiling point so the system is not supposed to be pressurized and will not freeze. Also anti-corrosion and particularly good with aluminium . Supposed to avoid cavitation in the system avoiding hot spots and generally an all round good thing. But as someone said to me what if you get a leak it could be expensive so perhaps not for a daily runner.
Excessively high concentrations of antifreeze are actually poor coolants. If you are going to use normal stock coolant and want maximum cooling then stay away from high concentrations as the coolant has a lower specific heat capacity than water. You want the concentration to be enough for corrosion protection as a minimum and then check if that meets whatever level of freezing temperatures you envisage.
hotrodder
Active Member
'Waterless' coolant is pretty much the dictionary definition of snake oil IMO...
With regards to things like specific heat capacity and thermal conductivity water is waaaaaaay better than ethylene glycol which in turn is slightly better than propylene glycol. Basically water is around twice as good at removing waste heat as neat ethylene glycol. This is why pretty much every car manufacturer in the known universe specifically warns not to exceed something like 55% antifreeze as doing so REDUCES the efficiency of the cooling system. Dunno about today but MB used to state this in the back of owners handbooks
Glycols are also a chunk more viscous than water i.e. more antifreeze = more parasitic losses although i doubt it'd make a measurable difference?
Several years ago Cosworth F1 said ...
Gylcols are a necessary evil in the cooling systems of road cars for protection against freezing. Obviously water isn't great from a corrosion POV so corrosion inhibitors are also added to automotive antifreeze. This is what varies with all the different flavours of antifreeze as there's various different ways to inhibit corrosion.
The usual 50/50 mix of antifreeze and water only raises the boiling point to ~ 107°C which is why the system is allowed to pressurise. The pressure caps job is prevent boiling after switching off a hot engine and to help when the engine is idling. At higher rpm the waterpump creates a pressure head as it's pumping away while the thermostat acts as a restriction to coolant leaving the engine...
As said nothing wrong with MB coolant. While MB aren't very good at preventing their cars from from corroding they don't actually make coolant, just spec a flavour. Traditionally G48 or G05 (both HOAT coolants with silicates for extra protection of aluminum parts subject to cavitation like waterpumps). These days i believe they have switched to G40 which is a Si-OAT flavour again using silicates. You need ~ 40% antifreeze for corrosion protection, this freezes at around -24°C so more than enough for most of the world.
Ignore the marketing BS and look up the msds for something like Evans NPG + and it'll tell you that it's ~67% ethylene glycol with the bulk of the rest of it being mostly propylene glycol i believe.
With regards to things like specific heat capacity and thermal conductivity water is waaaaaaay better than ethylene glycol which in turn is slightly better than propylene glycol. Basically water is around twice as good at removing waste heat as neat ethylene glycol. This is why pretty much every car manufacturer in the known universe specifically warns not to exceed something like 55% antifreeze as doing so REDUCES the efficiency of the cooling system. Dunno about today but MB used to state this in the back of owners handbooks
Glycols are also a chunk more viscous than water i.e. more antifreeze = more parasitic losses although i doubt it'd make a measurable difference?
Several years ago Cosworth F1 said ...
quoted from Inside an F1 Engine - Racecar Engineering Note how small the water capacity is/was... obviously there various reasons why they got away with just 4 litres of water but one of them (and the reason why the m104 engine in my s124 has 9.5 litres coolant capacity) is because adding glycols to water reduces heat transfer
Gylcols are a necessary evil in the cooling systems of road cars for protection against freezing. Obviously water isn't great from a corrosion POV so corrosion inhibitors are also added to automotive antifreeze. This is what varies with all the different flavours of antifreeze as there's various different ways to inhibit corrosion.
The usual 50/50 mix of antifreeze and water only raises the boiling point to ~ 107°C which is why the system is allowed to pressurise. The pressure caps job is prevent boiling after switching off a hot engine and to help when the engine is idling. At higher rpm the waterpump creates a pressure head as it's pumping away while the thermostat acts as a restriction to coolant leaving the engine...
As said nothing wrong with MB coolant. While MB aren't very good at preventing their cars from from corroding they don't actually make coolant, just spec a flavour. Traditionally G48 or G05 (both HOAT coolants with silicates for extra protection of aluminum parts subject to cavitation like waterpumps). These days i believe they have switched to G40 which is a Si-OAT flavour again using silicates. You need ~ 40% antifreeze for corrosion protection, this freezes at around -24°C so more than enough for most of the world.
Ignore the marketing BS and look up the msds for something like Evans NPG + and it'll tell you that it's ~67% ethylene glycol with the bulk of the rest of it being mostly propylene glycol i believe.
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