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01-16-2013, 09:32 PM
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#1
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Regular Member
Join Date: Aug 2012
Location: Sunnyvale,Ca
Posts: 46
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Bad lifter or ?
So i have a 1994 camaro z28 m6 with 110,xxx miles.
A few weeks back i adjusted the rocker arm nut(s) and im not sure if i adjusted them rite. I did the car on method, while having the car on i adjusted the rocker arms one by one, waiting for it to start clicking, then adjusting them till the clicking stop, and adjusting them 1/4th of a turn. (while car was on, there was no more clicking)
Finally, after all was done & i put the valve covers on. Theres is still a clicking sound on the passenger side far end, not sure what cylinder, but i think #8 (not sure).
Questions
#1 what happens if i tighten them to much or to little.
#2 when i pulled the valve covers off 2 rocker arms where/ are severly pushed down.
#3 What are the symptoms of a bad lifter, push rod, valves, piston etc
#4 it feels that i have to much, & or to little compress because its running really poorly rite after 3000rpms, it feels like the motor has to much air? Sorry if it doesnt make sense
#5 finally, lets say the lifters are bad or etc etc. What whould i have to change. for instance all lifters, rocker arms, pushrods, etc?
Thanks for all the help.
(sorry if im babbling and nothing makes sense)
__________________
1970 Camaro SS- Project 
1994 Camaro Z28 M6
1998 Camaro SS M6 Hugger
1999 Camaro SS A4 - Sold
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01-16-2013, 09:57 PM
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#2
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Regular Member
Join Date: Feb 2008
Location: Vancouver Isl., BC
Posts: 2,194
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#1 if you tighten them too much, your valves will be held open, and you'll lose power and cause severe top end damage. if you dont tighten them enough, they'll be noisy. your valves will float too soon, and you wont be able to rev out.
#2 do you mean pushed down as in.... the valves on that cyl. were open?..
ok lets stop here. let a shop adjust them for you. they wont charge you much. you're going to bust something. it sounds like you set them too tight.
either that or try the non-engine running method..
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01-16-2013, 10:05 PM
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#3
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Regular Member
Join Date: Aug 2012
Location: Sunnyvale,Ca
Posts: 46
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Quote:
Originally Posted by steveo
#1 if you tighten them too much, your valves will be held open, and you'll lose power and cause severe top end damage. if you dont tighten them enough, they'll be noisy. your valves will float too soon, and you wont be able to rev out.
#2 do you mean pushed down as in.... the valves on that cyl. were open?..
ok lets stop here. let a shop adjust them for you. they wont charge you much. you're going to bust something. it sounds like you set them too tight.
either that or try the non-engine running method..
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Im sure that its #1 of what youve posted. Yes, like if the valves on the cylinder are open. Thats what im going to do. Im also going to pay to get the new lifters, push rods. and bolts for the rocker arms to be replaced just to be on the safe side & be sure nothing got messed up
__________________
1970 Camaro SS- Project 
1994 Camaro Z28 M6
1998 Camaro SS M6 Hugger
1999 Camaro SS A4 - Sold
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01-16-2013, 10:08 PM
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#4
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Regular Member
Join Date: Mar 2012
Location: Newman Lake, WA
Posts: 529
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If you only tightened them 1/4 turn past zero lash, that's not enough. I typically adjust a factory stock setup to 3/4 turn past zero lash.
When you tighten the adjusting nut past zero lash, you're actually "preloading" the lifter a slight amount. By "preloading", I mean that you are moving the plunger inside of the lifter down into its bore by a predetermined amount.
You see, the outer body of the lifter does not directly push on the pushrod in a hydraulic lifter application. Inside the lifter, there is a finely machined bore with a plunger inside of it. The pushrod actually rides on this plunger and not the lifter body itself. The portion of the bore below the plunger, forms a hydraulic chamber where pressurized engine oil (via a metering device inside the lifter body) is constantly pushing up on the plunger to take up valve lash. When the lifter is on the base circle of the cam (valve closed), engine oil pressure forces up on the plunger to take up any lash in the valve train. When the lobe comes around and forces the lifter body upwards, a check valve seals the hydraulic chamber so no oil can escape and the plunger is forced upward (via this hydraulic chamber) along with the lifter body, pushing upwards on the pushrod.
When you are adjusting the valves, you are forcing that plunger down into the lifter by an appropriate amount so that there is room for if to adjust in either direction (longer or shorter), should the need arise. I like to run GM hydraulic lifters at appx. .060" preload. How many turns on the adjusting nut it requires to reach .060" preload is determined by the thread pitch of the stud and the rocker arm ratio.
If you preload a lifter too much, it can hold the valve open when on the base circle. Too little preload and they can be noisy, and if left that way can (and probably will) damage valve train components.
My method for adjusting hydraulic lifters is to do them one at a time. I place the valve that I'm adjusting in the center of it's base circle (ie. the valve directly opposite in the firing order is fully open). I then slowly tighten the adjusting nut to take up the slack while spinning the pushrod with my thumb and forefinger. I tighten the nut until I feel the pushrod tighten up and become difficult (new lifter) or nearly impossible (healthy, pumped up used lifter) to keep spinning with my fingers. This is zero lash! From here, simply turn the adjusting nut or poly lock the predetermined number of turns, lock it down (poly), and go to the next one. This method takes a little bit longer than the factory method, but is much, much more accurate. But once you get the hang of it, it goes very quickly, though.
Back in my Chevrolet dealer days in the early and mid-90's, we did more sets of valve guide seals on the TBI V-6's and V-8's than I can even begin to describe. Believe me, I've adjusted thousands of GM valve trains. The method I described above is definitely the one that I found will set them up properly and prevent any kind of issues down the road.
__________________
1995 Camaro Z-28, M6, Dynamic Customs 396 stroker, Scat forged 3.875" crank, Scat Ultra Q-Lite 6" H-beams, Icon forged pistons (4.030"), splayed 4 bolt w/ARP studs, 12.25:1, AFR 210 Eliminator heads (2.08"/1.6", 58cc chambers), Comp Ultra Pro Magnum XD 1.7:1 rockers, GM847 cam (234/242 .611"/.632"), Edelbrock LT4 air-gap intake, 24x conversion, LS1 PCM, TPIS 58mm throttle body, Bosch 42# "Green Giant" injectors, Kook's stepped LT's, custom stainless 3-1/2" ORY, Borla ProXS muffler...
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01-16-2013, 10:09 PM
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#5
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Regular Member
Join Date: Feb 2008
Location: Vancouver Isl., BC
Posts: 2,194
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i'm sure you just need to set them again. i wouldn't just go replacing that stuff..
replacing lifters is a lot of work. i doubt you bent a pushrod or anything either.
just set them again. new rocker nuts are a good idea though. i dont trust pinch nuts to stay tight after so long..
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01-16-2013, 10:23 PM
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#6
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Regular Member
Join Date: Aug 2012
Location: Sunnyvale,Ca
Posts: 46
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Quote:
Originally Posted by steveo
i'm sure you just need to set them again. i wouldn't just go replacing that stuff..
replacing lifters is a lot of work. i doubt you bent a pushrod or anything either.
just set them again. new rocker nuts are a good idea though. i dont trust pinch nuts to stay tight after so long..
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After reading so much & watching videos im sure i just need to set them again, Because it only makes a clicking noise when first turned on. After it warms up a little bit it goes away. Im 100 percent positive its just a rocker arm thats a little loose, which im sure its on cylinder #8? Well, ive orders the pushrods, lifters etc & will be stored just in case.
Im crossing my fingers hoping i just need to adjust them the rite way. I test drove it and there is a huge loss of power, which bugs me.
__________________
1970 Camaro SS- Project 
1994 Camaro Z28 M6
1998 Camaro SS M6 Hugger
1999 Camaro SS A4 - Sold
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