I have a pair of Merc 575SCI's with 274 hours on them. I just installed Superchillers with 3 1/2" pulleys and the first weekend on the lake I lunched a motor. I'm guessing it's a head gasket. Definitely water in the cylinder & oil pan.

Right when the motor really bagan acting up I noticed the boost was at 8psi and the other was at 5. Would the boost increase considering water was taking up space in the combustion chamber? I could have swore it was only 5.5 the day before. I was thinking that the air and fuel that was being compressed wasn't packing the cylinder they way it should and was backing up, increasing pressure. Any motor-heads out there familiar with this theory?

Anyone out there have my motors and added Chillers? Trouble free or a mistake????