Visible proof why you need 50/50 engine coolant

[Genie47]

Watch this video.

 

http://www.metacafe.com/watch/780996/bare_...sh/&source/

 

As he has described, it only works with water. Not beer or even carbonated water.

 

It is not a shockwave but serious cavitation.

 

Imagine you have 100% water as engine coolant. The combustion is contained in the combustion chamber but some of this force resonates outwards. The difference between the engine and that glass bottle is that glass is more brittle.

 

Small amounts of this vacuum is formed (cavitation) and then the liquid (water) comes back together producing this immense shockwave.

 

The interior lining is not 100% cast iron but a protective coating. Get this cavitation whacking it, I guarantee you serious engine issues.

 

So why does it need 50/50 antifreeze/water? Answer is above. It works with water only. Not beer or carbonated water. What do these have that is different with water? Gas. But 50/50 coolant does not have gas. Something is at work here. Viscosity.

 

50/50 coolant is thicker than pure water just enough to prevent cavitation.

 

I was inspired by Time Warp at Discovery. Here is their explanation of the phenomenon.

 

http://dsc.discovery.com/tv/time-warp/arti...eer-bottle.html

 

I now translate this phenomenon for engine use. You should have seen the Time Warp episode on it. The high speed camera going at hundreds of frames/second captured the bubbles forming out just before the bottle's bottom gave way.

 

Absolutely fascinating!

[Chucky2007]

cavitation most likely occus when radiator is 100% water only?

 

i am using Redline Water Wetter with water, no additional anti-freeze added, so is it safe from cavitation?

Edited April 6, 2009 by Chucky2007

[Yoongf]

Radiator cap is a pressure relief valve. Glass bottle dun allow pressure to escape. The tensile force generated by compressed air radiating outwards will crack brittle glass.

 

Radiator got pressure relief valve at the cap. Over pressure event will cause valve to release steam/water into overflow tank.

[Vroomtattat]

Hmmmm . . . interesting.

[Yeobh]

Main causes of cavitation on the cylinder liner outer diameter or cylinder block are bursting of air bubbles created by water pump impellers, cold water coming into contact with high temp metal surfaces. These air bubbles when burst can cause very high corrosion action on the metal surfaces. Cavitation is most apparent in heavy diesel engines.Most of the operators of such engines are very carefully in the using the correct type of coolant, using the right coolant and having the right mixture can prevent premature failure of cylinder bore liners which are very costly to replace.

[Genie47]

Yeobh already answered it.

 

Your scenario is over-pressure. Cavitation causes a shockwave. Nothing the radiator cap or overflow tank can alleviate.

[Trex101]

cavitation most likely occus when radiator is 100% water only?

 

i am using Redline Water Wetter with water, no additional anti-freeze added, so is it safe from cavitation?

 

The answer can be found at Redline website. Redline WW

 

Do click on the Redline Water Wetter Demo for RL explanation of their WW additives.

Edited April 8, 2009 by Trex101

[Yeobh]

The whole idea of using a 0.9 0r 1kg/cm2 pressure cap is to allow higher coolant boiling point ( the volume of coolant in the open unpressuried system is just no able to remove almost 70% of combustion heat generated. The coolant boiling point is also further increase by adding 50 or 70% anti freeze.

[Whyeme]

oh no...my ex ep80 only uses 100% tap water in the radiator...

should new cars go for 50/50 engine coolant?

if yes how to do it?

thks

[Yeobh]

Try ready mix coolant be sure to check which type of anti freeze yr ride originally come with - do not use colour as a guide.

[Trex101]

You can get those pre-mixed with 33% mixture or 50% coolant mixture.

[Yeobh]

May I just tap into yr into yr market knowledge, which type of coolant is widely used in Singapore - Propylene or Ethylene Glycol ?

 

 

[Shull]

from my knowledge of fluid mechanics, cavitation is caused the reduction of pressure in a short span of time(in the region of miliseconds), so low such that liquid will turn to vapour. But due to the significantly higher pressure from the surrounding, the vapour will collapse almost immediately. It's the collapsing which causes the wear and tear(and the resulting shockwave) in the glass..

 

In the context of a vehicle, the part where the coolant will experience such adverse pressure gradient is at the combustion chamber itself, where the cylinder move at such high speed that the pressure gradient will be very high. that said, i think the combustion process in an engine might produce higher force per cycle than cavitation do..

[Trex101]

May I just tap into yr into yr market knowledge, which type of coolant is widely used in Singapore - Propylene or Ethylene Glycol ?

 

Sorry i got no idea man as the only "coolant type products" we sell are water wetter.

[Heelntoe]

from my knowledge of fluid mechanics, cavitation is caused the reduction of pressure in a short span of time(in the region of miliseconds), so low such that liquid will turn to vapour. But due to the significantly higher pressure from the surrounding, the vapour will collapse almost immediately. It's the collapsing which causes the wear and tear(and the resulting shockwave) in the glass..

 

In the context of a vehicle, the part where the coolant will experience such adverse pressure gradient is at the combustion chamber itself, where the cylinder move at such high speed that the pressure gradient will be very high. that said, i think the combustion process in an engine might produce higher force per cycle than cavitation do..

 

How can coolant be subjected to combustion pressures generated in the combustion chamber? Unless you have a headgasket leak or crack in the cylinder wall

[Shull]

with my limited knowledge of internal engine combustion..IIRC, the engine oil lubricates the contact area between the cylinder walls and the pistons..it's this contact area that we'll find alternating high/low pressure..

 

Correct me if i am wrong though..

Edited April 10, 2009 by Shull

[Yeobh]

High temp and pressure are created within the cylinders due to combustions , the rapid and almost continous explosion for each power stroke creats shockwaves that are transmitted to the coolant jacket areas via the cylinder walls. Both the shockwaves and high temp does help in creating air bubbles within the coolant jacket areas.

[Heelntoe]

Always thought cavitation in engines mainly occur at the suction side of the water pump impeller, good to know something new. Did some search on cavitation phenomenon at cylinder walls and found this

http://www.mahle.com/C12570B3006C0D49/Curr...72NDCU600STULPL