Lash Caps or Oversized Eccentrics? Check valve?

[SlamedIAm]

While doing a valve adjustment with a buddy we came across the #4 and #5 exhaust valves not wanting to adjust to spec. To remedy this I went ahead and ordered 12 new eccentrics/bolts/nuts and readjusted the valves according upon their arrival. Unfortunately this still kept #4 slightly on the loose side and #5 is not making contact at all even with a brand new eccentric. The original eccentric had a visible flat spot and pitting.

Through some searching I've read that lash caps or oversized eccentrics are both possible solutions here. Is one inherently better than the other in the short or long term? I assume that either of these is essentially putting a band aid on a larger problem but I am not prepared to pull the head as this is a daily driver and I'm a college student entering grad school.

Would a compression or leak down test tell me how severe of a problem I'm working with?

Eccentrics I now have experience with but if lash caps are the preferred solution, how are they installed?

For background the car has experienced some bogging issues. I think it is fuel related as it was gone for 4 months after a fuel pump change but it's come back recently. Regardless I would like to eliminate this valve issue before further diagnosing that specific problem.

Thanks guys.

[jlevie]

In my opinion, oversize eccentrics are better than lash caps. But the big question is why those valves need either. I really doubt that the valve stem wore down, which means that the cam or those rockers are badly worn. Since wear on the cam badly affects engine operation I'd pull the head and repair properly.

[SlamedIAm]

If the head needs to come off I'll begin saving for one of MR 325's refurbished heads. This one was "rebuilt" by the PO with "good used parts" in a lot of places and I'd frankly rather get a fresh start than continue to fix short cuts I've found.

Is there any way to further diagnose potential problem areas through compression or leak down tests?

If oversize eccentrics are the preferred method I'll be replacing #4 and #5 with those in the mean time.

Another question, other than the increased ticking noises from the poor adjustment, what symptoms should I expect if the issue is a worn cam or rockers? What symptoms come from how misadjusted those two exhaust valves currently are?

[jlevie]

Short of removal, teardown, and measurement of parts there is no way to determine why those cylinders have excessive valve clearance.

A worn cam means that those valves aren't opening as far as they are supposed to. That will result in those cylinders not producing the power they should. To a lessor extent the same is true of worn rockers.

A compression test might show anomalous results for those cylinders, but then the results might not be remarkable. You already have the evidence that says something is a amiss.

[SlamedIAm]

Short of removal, teardown, and measurement of parts there is no way to determine why those cylinders have excessive valve clearance.

A worn cam means that those valves aren't opening as far as they are supposed to. That will result in those cylinders not producing the power they should. To a lessor extent the same is true of worn rockers.

A compression test might show anomalous results for those cylinders, but then the results might not be remarkable. You already have the evidence that says something is a amiss.

Not the answer I wanted to hear but thanks for your help jlevie. Time to start the new head fund