Quote Originally Posted by Barnacle Bill View Post
Looks like the bearings were turning in their seats. That happens when ran with no oil.
[QUOTE=Slab;These cam bearings are not separately replacable. The whole head would have to spin! lol[/QUOTE]

So like a Ford 5.4 3V Triton overhead cam engine the casting is the bearing. Although vertical Cams are used allowing oil to drain there is no combustion heat to melt the aluminum enough to transfer to the steel camshaft. The heat is just not there. That being said those camshaft bearing valleys in the head casting did Gall on the aluminum side. The Ebay castings galled even further. Ford repairs their head castings by Line-Boring the casting with the clamps in place then installs a new camshaft with .010 oversized journals for the repair. Its a one and done, you buy a new casting the next time. I happen to have one of those engines in my Fishin' Expedition. Respectfully speaking the case must be cracked, Crank & Rods checked for low or no oil operation too. Without doing that you may be pulling the head right back off along with the Powerhead. We may be able to find a complete block, I will call Tuesday as my guy is way too busy with oilfield customers on Mondays. I have bought a ton of good Yamaha F250-F300 used parts from him and all were good.