My boat quit running last week. After being towed to dock, I pulled the plugs and found water in #8 cylinder. I thought I had blown a head gasket so I pulled the head and the gasket showed no signs of failure. I had water in #2 & #8 cylinders and indications of rust in the #4 cylinder. I took the heads and had them pressure checked for cracks and they were okay for cracks but they were warped and twisted. At no time during this trip did the engine overheat. Do you think that this could be the reason for the water. I have inspected the exhaust manifolds and they seem to be okay. Can you suggest a good way to test them? There is no sign of water in the oil and no signs of cracks in the cylinders. Any suggestions as to what might have caused the water would be greatly appreciated.

I have a 1987 Supra Saltaire with a 454.

Signed a very frustrated boater and confused mechanic.

cowan4