 exhaust valve clearance keeps increasing |
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| mightyohm |
 Sep 6 2020, 06:10 PM
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#1
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Advanced Member  Group: Benefactors Posts: 2,279 Joined: 16-January 03 From: Seattle, WA Member No.: 162 Region Association: Pacific Northwest   |
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? Attached thumbnail(s) 
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Replies
| ClayPerrine |
Sep 6 2020, 09:31 PM
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#2
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Life's been good to me so far..... Group: Admin Posts: 16,542 Joined: 11-September 03 From: Hurst, TX. Member No.: 1,143 Region Association: NineFourteenerVille 
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It sounds to me like you are starting to lose a valve seat.
Clay |
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Posts in this topic
mightyohm exhaust valve clearance keeps increasing Sep 6 2020, 06:10 PM
Krieger Do you ever check to see if the rocker arm hold do... Sep 6 2020, 08:01 PM
mightyohm
Do you ever check to see if the rocker arm hold d... Sep 7 2020, 09:26 AM 914werke :agree: Sep 6 2020, 10:56 PM Superhawk996 :agree:
Valve seat is probably moving into towar... Sep 7 2020, 07:21 AM Bleyseng Order brand new heads from Len @ HAM now as your e... Sep 7 2020, 08:44 AM mightyohm
Order brand new heads from Len @ HAM now as your ... Sep 7 2020, 09:20 AM Superhawk996
Order brand new heads from Len @ HAM now as your... Sep 7 2020, 09:25 AM mightyohm
If you're gaining clearance seat is not reces... Sep 7 2020, 10:47 AM Superhawk996
What are the chances a failed seat could be repa... Sep 7 2020, 11:16 AM Bleyseng
If you're gaining clearance seat is not rece... Sep 8 2020, 12:13 PM mightyohm
Order brand new heads from Len @ HAM now as your ... Sep 7 2020, 10:06 AM KSCarrera The other thing to consider is that the pushrod is... Sep 7 2020, 09:53 AM yeahmag I’d think loosing a cam lobe to be the most like... Sep 7 2020, 10:25 AM mightyohm
I’d think loosing a cam lobe to be the most lik... Sep 7 2020, 10:27 AM Superhawk996 Also take a close look at that spring retainer. C... Sep 7 2020, 10:26 AM mightyohm
Also take a close look at that spring retainer. ... Sep 7 2020, 10:31 AM Montreal914 You can contact Jorge at European Motorwerks in Ha... Sep 7 2020, 01:15 PM djway A friend had a similar situation on a T1 rebuild. ... Sep 8 2020, 03:27 AM |
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