Quote:
Originally Posted by Army
Whereas the camshaft seems to be more askew when you compare the lobe positions with the nuts on the top of the valves. I know that this is a bit of a dodgy comparison as the valves probably aren't 100% vertical - well it must be difficult to get that perfect - when I lapped the valves into place I noticed an ever so slight variation in the position of the contact between the valve and the valve seat on some of the valves... that indicates some variation - I mean there has to be a little tiny bit of wiggle between the valve stem and the valve guide - it is a clearance hole.
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This raised a big red flag for me. And I have more bad news (you must be sick of me by now!), but I must say it.
ANY perceptible wiggle in the valve stem means you need new valve guides and consequently a total valve job. - which also, consequently requires some machining of the head surface. Sure, you can skimp a bit... but I have made the same mistake and I am now regretting it (and correcting it).
If there is any variation in the valve stem, the seal on the valve seat is lost, resulting in poor compression and the inability to accurately adjust your valves - when the time comes.
I promise, it will only get worse. The valves will become ovalized as will the seats in the head. The chattering / vibration of the stems in the guides will exacerbate the wear of the guides and continue this process.
This, in my experience, is the source of many rough running engines. People attempt to fix other things because these engine CAN run smoothly, but uneven compression happens differently when the car is running as opposed to when you do a compression test at 200 rpm.
I hope I have not ruined your day.