Click or Knock in Valve Cover

Could just be a stuck lifter,has it been sitting long? Some Marvel Mystery Oil or Seafoam would help that.

Little while back I had a tapping coming from my 351 it ended up being an small exhaust leak.

So been a while since I have been on the forum but the motor has been in to the mechanic and the problem has been found. The mechanic agreed that it sounded like lifter noise but when they pulled the valve covers they could not find the problem. Since they could not find the issue, the mechanic pulled the motor and and then the oil pan to search for the issue. They found some metal in the oil and eventually isolated the problem to a cooked piston and scuffed cylinder. Mind you this motor had no more than 50 hours on it since a complete rebuild...needless to say I am not using the same mechanic or machine shop. Everything else other the damaged cylinder and piston looked brand new so the mechanic believes that that cylinder was not clearanced properly when it was rebuilt. Screwed up the summer but should have it back for at least two more trips out to the Colorado river.

Words of wisdom from the experience would be always vet your mechanic. The one I used previously was a pain in the ass to say the least and obviously did not use a machine shop that new boat motors. It is apparent why they only offered a 90 day warranty for marine engines.

Good news is the mechanic I used this time is a family friend that has been building performance boat motors and race car motors for longer than I have been alive.

BOAT = Break Out Another Thousand...or in this case a couple

You've certainly been a trooper through all this.

I hope get a chance to get back on the water this season. It's great that you live in San Diego at least, that's a really nice thing in general. I actually skied in San Diego in January one time, just needed a wet suit. At least your season is never "over" like ours is, like lake is frozen solid over.