Water in the oil

[Phil Waterman]

Hi All

Three of the reasons I have always heard for using a 50/50 mix of antifreeze are:

1. Freeze protection down something like -35C even then it doesn't freeze like water hard but instead the water starts to separate out as ice crystals making a mush which doesn't pump through the engine very well.
2. Rust inhibitor, which depending on your local water can be very important in preventing rust. In the US even rain water may be acetic particularly in the North East.
3. Higher boiling point a 50/50 mix of antifreeze even in a non-pressurized system has a significantly higher boiling point than just plain water. Going to one of the company data sheets they list boiling point as being 107C (226F)
   and freeze point as -37C (-34F) for 50/50 mix.

On one occasion when setting up a new engine 261cu.in. for my C60S I didn't use antifreeze or rust inhibitor while I was testing the engine and had significant rust damage to the water pump adapter plate in a very short period of time. Rust pitted the plate to the point that it had to be replaced because of a weeper leak in the sealing surface. Lesson learned now I always use either rust inhibitor or antifreeze any time I fill a cooling system.


I have also seen the difference in cooling once when having a cooling problem on my Pat 12 C60L as I blew water out of the system because of overheating and replaced it on the move with a pressure pump putting water back into the system the overheating kept getting worse and worse as the antifreeze in the engine was gradually replaced by plain water.


Cheers Phil