Hello everyone,
I have an engine that experienced water intrusion into cylinders 3&4 on it's last couple of outings (accompanied by overheat alarms). The cylinders were emptied, and the boat was winterized and put away. The 295 hour boat/engine has since sat (indoors) for 15 years, waiting to be resurrected.
This boat has been held onto for 15 years for sentimental reasons, so bringing this specific engine back to life is this winters goal.
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The head and head gasket were removed for inspection, as well as the exhaust gasket. The head gasket was in perfect condition, but the exhaust gasket was clearly deteriorated and was an obvious path of water to enter the exhaust chamber, with evidence of "steam cleaning" in the exhaust.
What appeared to be a simple exhaust gasket swap has since gotten significantly more involved...
After sitting for so long, the engine was seized. The power head was pulled, and a soaking of 50:50 ATF:diesel broke it loose with very little effort. Because of being seized, no compression readings were taken before removing the head (big mistake).
Looking at the pistons, they all share a common "chip" in the top left corner, accompanied by a chip at the same position on the uppermost exhaust port. The crowns of pistons 1 and 3 are also in suboptimal condition, and there are drag marks on the bottom of the head for those cylinders.
Looking through the exhaust ports, it seems that all four cylinders could use new rings. The cylinder bores are in remarkably good shape given the condition of the pistons/rings, but cylinder 3 does have a series of broad grooves in the bottom left (matching another chip in the piston) that can barely be felt with a finger. Amazingly, aside from the water intrusion, the engine was running very well before being put away.
With all of that being said, I am looking for a little insight from those with more experience:
Based on the provided information/pictures, is it likely that a complete rebuild is necessary? If so, would oversizing all cylinders be necessary, since the broad grooves in cylinder 3 can be felt with a finger nail? It is a bad idea to reuse wrist pin and crankshaft bearings, given the chipping/pitting on the pistons/rings?
This is my first major engine project, so any advice/guidance that anyone can provide would be incredibly appreciated!
I have an engine that experienced water intrusion into cylinders 3&4 on it's last couple of outings (accompanied by overheat alarms). The cylinders were emptied, and the boat was winterized and put away. The 295 hour boat/engine has since sat (indoors) for 15 years, waiting to be resurrected.
This boat has been held onto for 15 years for sentimental reasons, so bringing this specific engine back to life is this winters goal.
--------------------------------------------------------------------------------------------------------
The head and head gasket were removed for inspection, as well as the exhaust gasket. The head gasket was in perfect condition, but the exhaust gasket was clearly deteriorated and was an obvious path of water to enter the exhaust chamber, with evidence of "steam cleaning" in the exhaust.
What appeared to be a simple exhaust gasket swap has since gotten significantly more involved...
After sitting for so long, the engine was seized. The power head was pulled, and a soaking of 50:50 ATF:diesel broke it loose with very little effort. Because of being seized, no compression readings were taken before removing the head (big mistake).
Looking at the pistons, they all share a common "chip" in the top left corner, accompanied by a chip at the same position on the uppermost exhaust port. The crowns of pistons 1 and 3 are also in suboptimal condition, and there are drag marks on the bottom of the head for those cylinders.
Looking through the exhaust ports, it seems that all four cylinders could use new rings. The cylinder bores are in remarkably good shape given the condition of the pistons/rings, but cylinder 3 does have a series of broad grooves in the bottom left (matching another chip in the piston) that can barely be felt with a finger. Amazingly, aside from the water intrusion, the engine was running very well before being put away.
With all of that being said, I am looking for a little insight from those with more experience:
Based on the provided information/pictures, is it likely that a complete rebuild is necessary? If so, would oversizing all cylinders be necessary, since the broad grooves in cylinder 3 can be felt with a finger nail? It is a bad idea to reuse wrist pin and crankshaft bearings, given the chipping/pitting on the pistons/rings?
This is my first major engine project, so any advice/guidance that anyone can provide would be incredibly appreciated!
