Re: Coolant additive

Posted by longjohn On 2013/10/12 13:59:01

These "wetter" coolant additives are surfactants (soap is a surfactant). Surfactants lower the surface tension of water. Cast iron engine blocks quite often have rough spots in the water jacket which will create a hot spot. The water near the hot spot will form a vapor bubble, reducing the effective surface area of the water jacket. A surfactant will help dissipate the bubbles and effective increase the surface available for heat transfer.

Since every engine block is different, these additives may help or may be useless. The easiest way to tell if this will help your engine is to try it but don't be surprised if it doesn't work as advertised. I've tried it in both my Packards and it didn't make any difference in either.