Can anyone explain this?

[StereoInstaller1]

From an M20B25 I got pre-dissasembled:

[whiltebeitel]

Aer you meaning the wear on the camshaft or what looks like a flat spot on the lobe?

[JasonC]

Looks like a worn lobe, time for a higher lift cam.

[nando]

the oil tube that runs over the cam will clog eventually, esp. if you use crap oil and don't change it very often. that's likely what caused the cam to wear like that, judging from the amount of sludge in that picture. the flat spot is probably just where the heaviest load on camshaft lobe is located, so it wore away faster there.

[Sean]

Yea, that's a nice edge right there. Ouuch.

[Jordan]

the oil tube that runs over the cam will clog eventually, esp. if you use crap oil and don't change it very often. that's likely what caused the cam to wear like that, judging from the amount of sludge in that picture. the flat spot is probably just where the heaviest load on camshaft lobe is located, so it wore away faster there.

Yup, thats pretty much it. I'd recommend a new camshaft. Used stock in good shape or a new Shrick billet made to your specs from TopEnd.

[StereoInstaller1]

I was given a shell (91 325i) to "dispose" of.

Motor is just fucking wasted.

I am hoping the head is OK other than that nasty ass cam and the equally nasty rockers...since I just happen to have spares.

I might build this car as a swap, M50 and 5 lug, or just make it stock and sell it. The body is pretty clean, the front bumper is cracked but the rear is fine. Left fender is crumpled, but tons of other stuff is pretty decent.

Dunno, just sitting on it for now.

Luke

[browntown]

get back to work! mach schnell. :-)

[nando]

the head might be ok for a rebuild, as the cam bearings get their oil seperately from the cam lobes. the only way to know is to take it apart and check out the bearing surfaces.