1977 Glastron V174. I have found some horizontal cracks in the block of my Mercuriser 165 (6cyl Chevy 250ci) engine exactly where the manual said they would be. The head on my engine was also warped causing the head gasket to eventually go. For now I am going to JB weld the cracks and finish the season up on this engine. I still haven't had this boat on the water, the cracks are not leaking and I need to see if this boat is even worth putting the money into a block. If so, I plan on marinizing an auto engine off season but have some questions:
It is obvious these cracks were caused by no winterization as the engine drain plug was also seized and I had to drill it out/retap it, but I want to know what the root cause of the head gasket issue is.
Did the freezing water cause the cracks and the warped head (head is warped .013"; limit is .007" and .003" within 6")?
Did the freezing cause the cracks and the cracks allowed the head to stretch and warp?
I have also found some burnt spark plug wires so:
Is it possible that the block cracks and he head warping are two separate incidents? Cracking caused by freezing and warped head caused by overheating?
Pictures of cracks and attempted repair:
It is obvious these cracks were caused by no winterization as the engine drain plug was also seized and I had to drill it out/retap it, but I want to know what the root cause of the head gasket issue is.
Did the freezing water cause the cracks and the warped head (head is warped .013"; limit is .007" and .003" within 6")?
Did the freezing cause the cracks and the cracks allowed the head to stretch and warp?
I have also found some burnt spark plug wires so:
Is it possible that the block cracks and he head warping are two separate incidents? Cracking caused by freezing and warped head caused by overheating?
Pictures of cracks and attempted repair:
