Cam box cam tower wear

[jon8christine]

As I go through my now completely torn apart engine and look for wear normally found on an old engine with 105k miles the only thing that concerns me is my exhaust cam box tower whichever name you prefer. There are no replaceable bearings for the bearing surfaces of course, so that doesn't help. The middle has some wear masks, but generally looks like the intake side and I'd consider it ok, but it's my first time looking at them.

https://drive.google.com/file/d/11tBXVb ... p=drivesdk

The pulley side 'bearing' has a little more wear but has some interesting cross scratches

https://drive.google.com/file/d/1225SJ4 ... p=drivesdk

The end is the most concerning. There is more wear and a groove big enough to catch your fingernail and corresponding wear on the cam shaft.

https://drive.google.com/file/d/12cBw6H ... p=drivesdk

https://drive.google.com/file/d/12bhypo ... p=drivesdk

https://drive.google.com/file/d/12DfGKI ... p=drivesdk

So the question is, are they useable since they aren't available new, or do I need to look for some in used but better than this condition? New 40/80 cams are the current plan.

The tappet cups also have some wear where they contact the end of the valve stem. Thoughts on whether or not these are ok, or need replaced? It again is enough to catch a fingernail on.

https://drive.google.com/file/d/12m6pRt ... p=drivesdk

[18Fiatsandcounting]

My $0.02 worth: Replace the cam housings and tappet buckets. They're readily available in better shape than yours, and since you're replacing the cams, a new set of housings and buckets along with the new cams should be fine.

At the same time, the scoring on the cam journals and cam housing faces indicates that, at some point, you had really (really) dirty oil passing through those areas. It would be nice to know what happened so that history doesn't repeat itself.

-Bryan

[jon8christine]

Yeah I'd like to know too, unfortunately I've only put 1,000 of those miles on. Oil pressure has been low but someone else has been in the cam/ head as one of the corner tower bolt holes into the head was drilled and bolted through.

[Odoyle]

If you have a copy of the factory manual you can measure and compare specs instead of guessing. There are callouts for the shim bucket clearance and cam box bores..

[Nut124]

I'd be concerned about the cam box cam brg wear but not about the under bucket shine where the valve stem hits. If the bucket shows major wear in the bore that could be a concern.

Put a known straight cam in the box and place it on true flat and examine straightness of the box to head surface with a feeler gauge. A timing belt too tight can wreck the cam brgs. The same for over torqued cam box bolts. Or dirt in oil passage like Bryan states.

[18Fiatsandcounting]

...one of the corner tower bolt holes into the head was drilled and bolted through.

I agree with Nut that the camshaft housing "bearings" are more of a concern than the tappet buckets, but I'm wondering if the drilling you mentioned was done with the head in place, with little (or no) attempt to catch and remove the metal chips, and some of these found their way into the cam housing oil and then the bearing surface, causing the scoring you see?

-Bryan

[RRoller123]

The "Bearings" for those cams is using the term loosely, indeed. I think I have a problem up in the cam boxes as well, not isolated yet though.

[jon8christine]

Took the block, head, crank and rods to the machinist today so he could clean, check etc and let me know what size stuff to order. While I was there he looked at the cam boxes and cam shafts and said they weren't bad and to clean them up with some scotch brite and reuse them with the new cams. He also looked at the tappet cups and said they were fine to reuse too. Guess I'll see how well they clean up and ask him again when I drop off the new pistons etc.