It is a "new to me" motor. Just a terrible set of circumstances. The mechanic has worked on this boat many times over its lifetime and he offered to do the rebuild as a "flat-fee" favor to a long-time customer (me) and probably wanted the challenge. But we were hit with many setbacks including personal loss which had him reevaluating his life and then an injury that delayed us even further. All totaled we are 21 months since delivery of the boat to his shop.
The long block purchased was for a Ford car engine. There is some thought as to whether it should have been a marine engine block. The mechanic said it didn't matter. Maybe it did more than we know.
The "knocking" was evident after the first sea trial. Here is THAT video:
https://www.youtube.com/shorts/LlirA0SUerQSince that video he has torn down the engine two more times to replace the lifters - and we still get that knock. He may very well know it is the rod but doesn't want to dig in that deep again. He is a good man and sincere so I don't blame him.
To elaborate on my conversation with the shops -- there is no sympathy for the work done before they get it. I will try to negotiate with them as I will not need new exhaust manifolds or water pumps or a lot of the other things we might replace during a teardown because they are already new. The top end is great. So maybe I have a little wiggle room if it's just a bottom end rebuild. Marine shops are having a difficult time with the manufacturers quality of these blocks and their unwillingness to cover labor costs if their blocks are indeed defective -- and there's a lot of labor put into the rebuild before they even fire up the engine. Good relationships with block manufacturers appear to be at a minimum.
Here is a question i should entertain that I hope someone can answer: What should I do with the boat if I do not want to invest more $$ to fix it?
The hull and upholstery is top notch (stored indoors all these years). But it is all worthless if there is no motor. Is there a market for good bones of a boat? (and a trailer that is slowly rusting)