Originally Posted by DirtyDog
Ok. I think I have a good theory on the demise of this topend.
1. From your pictures, the right side cam caps were BOTH installed backwards. In motor assembly, indicator arrows always point to the front of the engine.
2. Because the head, cam, and cam caps are all "machined together", flipping them around could likely change the fitment. I'm guessing this was done at a valve shim swap by the PO. You didn't list the valve shim specs as you found them, did you?
3. If the cam caps were installed backwards (with a poor fit), torqued to spec, and later discovered "worn" as you see them, then the tight/poor fit could be partly to blame for the poor lubrication which compounded the issue. Once they scored, the torque spec probably went into the crapper and they were later discovered "finger tight".
4. This above combined with low oil pressure caused by a) a leaky oil banjo bolt, b) a poorly fitting K&N oil filter (which wasn't likely filtering the shavings adequately), c) a severely clogged oil screen, and d) possibly the PO under-filled with oil.
And a tip-
Don't bother trying to re-install that water pump shaft seal. Buy a fresh pair.
Also, I've noticed these K&N oil filters don't fit worth a damn. Go with the Hi-Flo variety instead.
Great suggestions! I noticed the arrows on the cam caps didn't seem to be pointing the right direction when I was taking it apart. I wasn't sure at what point they were set that way. I remember the PO mentioning that he had someone look at what was making the noise. Not sure if it was them, or another previous mechanic/owner.
I didn't notice that the K&N filter didn't have the best fit. I'll try and find one of Hi-Flo filters that you have mentioned.
Originally Posted by newcastleadam
Ditto on the good write up and pics. Couple of tips, things to consider, etc:
the water pump impeller has an O-ring in there, it's much easier to screw it on and off the pump shaft
Take a good look at the oil seal on the inside of the clutch cover, it can get nicked and it's much easier to deal with now
Good points! I'll make sure to mark those down on my todo list.