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Originally Posted by skunkworks
Is there a differance between 1st and 2nd gen? I assume they where first gen - 92 stealth. The hole in the top looked to be less than a mm in diameter. No wonder they get plugged. What I bought is what has been called 3rd gen lifters from partsdinosaur.
sam
Any runs yet to see if it has helped the knock?
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I have 1G lifters with the tiny holes and they have always been quiet (except when I am due for an oil change I get a hint of ticking)
I am not convinced that the hole on the top of the lifter is the issue - there is obviously some other internal orfice that holds the lifter up independent of oil pressure.
Not sure what you are planning to do with your old lifters - I would be interested in getting my hands on some "noisy" lifters to better understand the failure mode.
KNOCK
My old seals were so hard/oversized they would slide up/down the stem with zero resistance. Must have been allowing all kinds of excess oil into the combustion chamber. Confident my oil consumption will drop dramatically as a result of changing VSS. (Jury is out on whether the valve guides are worn at 175K. I could not detect any play by hand - not sure how to mesure valve guide wear or if it is even possible with the head on the engine.
Immediately after replacing the seals, I was getting some knock from the excess oil in the cylinders but it quickly went away. I still have an extra 3% fuel dialed in that I will remove to see if the knock is 100% gone.
NOTE: My spark plugs have been running gray-white in spite of good O2 voltages due to the excess oil. Positive sign if they start running gray-tan indicating lower combustion temperature.
I need to re-check compression tonight to confirm that it returned to 155 PSI. Even after compressing the lifters I was only getting 90 PSI in one of the cylinders - although on some of those lifters, I tried bleeding out the oil using a paperclip instead of the tried and true vise technique. In the future, I would only use a vise to reset the lifters.
REALLY BAD IDEA
Contrare to my understanding, there is a LOT of oil being pumped into the valve train of these engines. I ran the engine for a few seconds with the front rocker panel off (to see if it was getting lubricated) and by the time I ran back to turn off the engine there was oil splattered everywhere. Really bad idea.
Clint