This cracks me up if I changed every detail that everyone said was a cause I would have even more money wrapped up in it, look at the big picture, crossovers, many guys run them including myself for years no issues, why change it? I mean come on.... I wish there was ONE SOLID answer on why this happened we may never know could have just been a part fail that's it, might be guides, might be lifter or other things... But sure seem to have it narrowed down... Crossovers didn not cause this, if the heads were set up as marine and I find all huides minimal of .0018-.020 I will look at later because my buddy been running crossover with 800 + hp engines for 10 years with zero issues and almost no water temp in engines....

Please don't come on here asking for opinions and then be a dick when you get some opinions. I did not say this was 100% crossover failure like others have with their opinions. I'm only asking questions to try to help with your issues. I had that failure when I switched to aftermarket heads.
I know your upset, we are only trying to help.
These are not the old engines out of the Scarab III?

Not trying to be a dik, but some of these things had zero effect on the problem at hand...

The scarab engines are long gone every part here is brand new and of good quality.... Should last more then 1.5 easy hours. Didn't even go wot at all that's bs

I will be done now I will keep my stuff off the grid it's probably better that way and figure it out with local guys that can see what happened ...

Shot in the dark see if the intake rocker arm on that cylinder feels free on the bearing.

All that was in good shape, this is so odd..

What rpm were you spinning were this occurred?

Full Force, you mentioned that you have a lifter stuck in the bore - I am assuming it is the intake for the bad cylinder. If that is the case, was there any damage to the pushrod? I would be fairly suspicious that this is the root of the problem. If the valve had galled in the guide and become stuck open, I would not expect it to cause the lifter to also get stuck in its bore, unless perhaps the valve stuck in its guide while partially open. Hope you can find the cause and get it back on the water soon. And yes, I definitely feel for you - after the problems I have had with my rig, I was also kind of wishing I could just go back to a stock build so I could leave the hatch down and enjoy the boat. Good luck with it, and please let us know if you discover the cause. Doubt if you care much at this point through the frustration of it all, but it might help a fellow OSO'er down the road.

Cole, pretty sure he said he was running about 5200 RPM when it happened.

Been on Phone with Bob M we are looking Into cause and said he will do whatever he can to help me out and have a good outcome for both of us.

we all know that pictures on the net can be hard to see clearly and it is not possible to diagnose what happened without having the parts on the bench in front of you for taking measurements and for examining.i am pretty sure i know the cause of this failure but without having the parts in front of me for inspection i could only speculate without facts.the court of public opinion will not give an acurate answer on what truly caused this failure.