E28: How long can I go with a worn out camshaft (first lobe)

["Pogozelski, Andrew A." <apogozel@xxxxxxxxxxxxx>]

Greetings,

I have a 1985 535i, 185k, and during my recent valve adjustment job I
noticed
that the first lobe on my camshaft (exhaust valve) is pretty badly
shaved down
by about, I'd say, 1/16 inch!   The rocker arm end that rides on it is
also visibly 
worn (out of round shape, concave in the middle). This is only that one
lobe, all the others are perfect. 
I have known about the cam problem for the last, say, 85k miles, and it
has gotten worse over the years. I can hear a hollow ticking or
knocking, especially
in the enclosed areas, like a garage, I assume, it comes from the
camshaft.

To all the E28 people, how long can I go with that camshaft?
Another 100k? (just kidding!).
What's gonna give?

I do not feel any performance degradation, the car runs like a champ,
very strong, fairly smooth idling, does not burn any engine oil (Mobil
1, 15-50, every 4500-5000 miles for the last 2 years).
I understand it's a common thing on older E28's and I have read about
the reasons.

Am I being neglectful?  Does this affect any other systems in a harmful
way?
To me all it does is that the exhaust valve is not being pressed all the
way down (short by 1/16 plus another 1/16 from the rocker arm end) so
that the combustion gases pass by the valve faster and at a higher
pressure, a restricted exhaust opening - so what?
is it gonna damage, e.g. burn, that one valve?

Would like to know if there are other E28 drivers who are aware of the
worn first-lobe driveshaft and wonder how long they can get away with
that!

Any thoughts and comments from E28, and non-E28, drivers - greatly
appreciated.

Andrew Pogozelski
1985 535i, 185k, a strong, fun to drive machine even with a 'trimmed
off"
driveshaft lobe.
BMW CCA #92029  
 

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