I have an interesting question that I've been kicking around with some friends and noone can give a good answer. I had a 53 merc flathead that had a cracked block where in the mornings you would have to pull some plugs out so the water that worked its way passed the water jackets could escape. Now the question is once you dried off the plugs the engiine would start and it would run fine except for alot a white smoke. Why would the engine keep runniing with all that water passing the water jackets and covering the spark plugs. I know alot was burned off but you would think it would have drowned the plugs. Just a interesting question some friend and I have been kicking around.