How does this happen to a rocker arm and shaft?

[lsf911]

In process of taking apart my engine. Finally got around to the cam towers and heads.
When I removed the rocker arms and rocker shafts, #1 on the exhaust side had lots of score marks on it. Everything else looked fine with the exception of a broken chain ramp on that same side (left bank).

Just wondering, what would cause this to happen? Pictures below...

[Flat6pac]

That’s one of the very early rockers, but after the forged ones time, and there is no brass but iron on steel.
Check the rest because an 83 will have brass bushings.on all.
Bruce

[lsf911]

Thanks Bruce, this came out of a 69E 2.0 engine not my 83. Any idea what would cause only one to fail? The rest are the same type and look great.

[Richey]

Plugged hole in spray bar/tube could cause this .

[lsf911]

Thanks for the response Richey. I looked at spray bar, it looks clear but I will make sure it's clean before reassembly.

[targa72e]

The early rockers like this had no bushings and the shafts had a coating to try and keep them from galling. You can see the dark coating on the ends. I have a set of these early shafts and rockers for sale is you need a replacement.

911 rocker arms and shafts $75

john

[Walt Fricke]

Why not do what Porsche did - change to bushed rockers? Some one like Cgarr (Craig Garrett)could tell you if these old style rockers can be rebushed. It is not like Concours judges could tell.