[Bored&Stroked]

I use a water-glass type product as Ronnie mentioned. I buy Moroso Ceramic-Seal . . . getting it from Jegs. You must follow the instructions and use clean water. If your engine already has anti-freeze, then you'll need to go back to straight water - and I'd "rinse it through" a couple times - before using the ceramic seal. Also, drain the ceramic seal as they recommend - right after you get done with the running of the engine.