exhaust valve clearance keeps increasing Options

[mightyohm]

Hey all,

Long time, no posts.

I am having a hard time keeping the valves adjusted on my 914. I stopped driving the car a few years ago due to this issue, but have started working on it again. The clearance on #1 exhaust keeps increasing rapidly between adjustments. (The valve is getting looser and louder.) After a few hundred miles, the valve is making an awful racket. I just checked clearance today, and after about 1000 miles I had several times the specified 0.008" clearance (it could easily have been 0.050" or more - too big to measure). I adjusted the valve and I am running out of adjuster screw! See the attached pic. The other valves are fine.

Any idea what's going on here?

I pulled out the adjuster and it looks relatively fine - some flat spots from running with extreme clearance but it's not like the end is worn off.

I pulled the pushrod years ago and it seemed ok. But I should probably pull it again.

The car has solid lifters (I believe they are ceramic, installed years ago).

I would think that if I was dropping a valve seat, the valve would be tightening up vs. getting loose. But that could be what is going on. The car runs fine once I adjust the valve.

I would think that if the cam is losing a lobe, it would affect two opposed cylinders. Only #1 has this problem.

Any other ideas before I tear it apart?