I am pleased to announce that the problem is not with the intake valve or seat. please read on...
Now, I must worn you. What I am about to disclose goes against everything I have been taught regarding engine building. However, I was at the end of the rope...
The saga contiues with me laying flat on my back looking up at the bottom of the engine and trying to convince myself that RIMCO had just done a bad job on my head. (spark plug threads aside) I just could not believe that teh seat would fail...) So, per the last thread I took Otto's advise and backed off the strainer nut to about 6 ftlbs...but before I quit I got the bright idea to start eliminating some of the variables in the valve train, so I swapped the rocker from the problem valve, number 4 to intake 3.
The next test run, about 150 miles, ended with a tight number four valve. Back under the beast...
Here is where some will whence. I decided to move the lifter and push rod from number four intake to number 2 intake. a swap...( rationale, I fingured that both lifters have a relationship with that cam lobe and although slightly different would hopefully have little impact.) I did the normal re-adjusts and off to a road test.
This road test was interupted by the number one spark plug ejection...repaired with a Timesert sleeve. Worked very well. (My in car process included greasing the reamer/ tap, a shopvac in BLOW mode on the tail pipe and the exhaust valve adjusted open.) more on tha later if you want the details.
So, back on the road again. I logged jsut about 200 miles since the (whence) swapping of lifters and push rods and ...
Drum roll please. Guess which valve is tight now.....
Number 2 intake! Are you kidding?! No I am not!....
the tight valve starts to surface with a slight miss at idle. then it progress to a lopeing idle. Pull a plug wire or an injector and there is no noticible change. This pointed me directly to cylinder 2. A quick compression test reveled 90 psi. I must admit that I was disgusted but also had a goofy grin on my face.
Quickly jacked the car up pulled the wheel and popped the valve cover off. rotated the engine to TDC number 2 and ... even thought the engine is hot there would be some clearence right? but no..zero clearence on the intake. The number 2 exhaust measured about .004" hot.
Confirmed that the problem follows the lifter/pushrod assembly.
BUT WHY!!!!!!!!!!!!!!!!!!!!!
Could this lifter be hanging up in the lifter bore? It showed no evidence of abnormality when I had it out.
The push rod is not bent nor did it appear to have lifter to pushrod cup seat alignment problems.
My thought was to swap out the push rod with another and see if the problem follows the rod? Or, just repalce them both with spares. How would yuo guys handle the lifter? Buy a new stock or try and use a good used one ( if there is such a thing).
This is the the point where I ask you guess to suggest next moves...
Thanks agian for all of the brain power to date.
Scott