I know this subject has been beaten to death, but I still have a few questions, please bear with me.

Just finished adjusting my valve lash with the motor running, using the open-top cardboard box splatter sheild suggested by a forum member. Worked slicker 'n owl poopie I might add. I wasn't thrilled to remove the alternator for something like this, but whatever it takes, I guess. This brings me to my first question;

Q: Does anybody know the name/address of the GM engineer responsible for locating the serpentine belt tensioner on the LT1? I'd like to have a word with him.

There was some bonus entertainment too, as I adjust to 3/4 turn past zero lash, the idle goes lumpy for a few seconds before returning to normal.

Q: Can somebody tell me WTF that's all about?

My stock rocker arms still seem to have some lateral play in them even though there is tension on the pushrod, bringing me to the next questions;

Q: Are aftermarket roller rockers more positively located than the stamped steel variety? I assume they must be to keep the roller perpendicular to the valve stem.

Q: Do billet rockers eliminate any valve clatter compared to stock rockers? This car positively rips, but I still don't like the way it sounds. I guess I'll drown it out in exhaust boom eventually.

The last question concerns one of those mysterious indescribable noises, but I'll take a whack at it anyway. Once per rev I get an 'oink'. Not the sound a pig makes, but if you say the word aloud, you're getting close. It's almost lost in valve clatter but definitely there.

Q: Could a worn valve guide make this kind of noise?

Thanks for your patience and in advance for your feedback.

 

TTT

 

The engineer's name was Professor Rubin Goldberg. I'm sure you have seen some of his other creations. I'm sure it was he who specified the location of the third A/C compressor bolt too. Also, I bet if you look around everytime the car makes that "oink" sound, either a mustang has just driven past, or my ex wife is in the neighborhood. :jester

Congrats on the "right stuff" valve adjustment. The lumpy idle comes while the oil in the lifter is getting adjusted to the new clearance.

Seriously, the "oink" could be a pushrod rubbing on the head. Have you ever had them out? If you do, roll them on a piece of plate glass to check for bends.

My roller rockers are a lot closer tolerance and less sloppy than my old stamped ones were. I don't think that there is any lateral movement to speak of. On my 85, we added pushrod guide plates when the engine was put back together. I don't think that you should hear valve clatter at all with properly adjusted valves.

[Modified by NHVett, 4:03 PM 3/29/2002]


[Modified by NHVett, 4:09 PM 3/29/2002]

 

:lol: You absolutely NAILED it!

Thanks for the tip on pushrod clearance, I'll check that next.

Regarding valve clatter, it was still ringing in my ears when I originally posted, after listening today WITH THE COVERS ON it doesn't sound too shabby after all.

Another couple notes that may be of interest:
I'm surprised at how well you can hear the workings of an individual valve using a mechanic's stethescope by placing it on the rocker stud. Sticking the end of that thing in there with the engine running also direct-injects that V8 throb into your brain. Dangerously addictive.:reddevil

The effect adjusting the lash had on valve timing is subtle but noticeable. What was a fairly smooth idle now has me looking at the tach to see if it's still running (those factory mufflers have got to go), and the engine revs more smoothly over the entire range. The power is less edgy but I'm sure there's more of it. I'll confirm this when the roads dry out a bit tomorrow.




[Modified by rocketfinger, 6:21 AM 3/30/2002]