I had a 51 Ford flathead 6 when I was in high school. On rainy days, water would pool up in the #1 cylinder spark plug indentation in the head, and the truck wouldnt start, or would run poorly. It seemed that the water was running down the upper radiator hose, and pooling in the plug hole. I was able to solve this by wrapping a rag around the bottom of the hose, where it joined the head outlet.
It evidently absorbed the moisture, as the truck ran fine rain or shine after that. I had heard others at the time complain about flathead sixes that ran carppy in the rain, maybe this was the problem?
Nick
