87 S-10 truck, 2.8 ltr

Tiny
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  • 1987 ALL OTHER MAKES ALL OTHER MODELS
When are the valves considered down? When the small end of the rocker is fully down, or when the small end of the rocker is fully up? I know that when the mark of the shaft reaches the timing scale you are either in NO 1 position or NO 4 position, I just need to know when the valves are considered closed.
Monday, February 26th, 2007 AT 12:39 PM

8 Replies

Tiny
CHEVY22
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Hey guy , i cant get a real answer even from my gm software but i found this


https://www.2carpros.com/forum/automotive_pictures/59481_87s10_1.jpg



https://www.2carpros.com/forum/automotive_pictures/59481_s102_1.jpg



maybe its too old for any good info ,???

im trying

jim

i know you cant read those , save them to your computer and blow them up on your pic program
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Monday, February 26th, 2007 AT 4:14 PM
Tiny
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I figured out the valve closed deal no ive got two more questions
1. When adjusting the valves(lash etc) in the no 1 position the #3 exhaust valve is to be tightened, but the nut is barely on the threads before the lash is removed, then in the #4 position it is really loose and I know it will rattle like crazy if left that way, what am I doing wrong?
2. There are three marks (lines) engraved on the crankshaft, two small, and one large, the large one is the actual timing mark correct?
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Monday, February 26th, 2007 AT 7:12 PM
Tiny
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What I have found states the large mark is the correct mark and if timing is correct #1 valves should be closed and in theory #4 should be closed, im having a hard time here too, the info is really bad I guess because its old
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Monday, February 26th, 2007 AT 7:25 PM
Tiny
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Ok got it on the timing mark
when that number 3 exhaust valve is tightened in its no1 position, the nut of the rocker arm is much higher than all the rest when the lash is gone. But when rotated 180 degrees in the no 4 position it is really loose, so loose I can almost pull the push rod out, that cant be right it would make alot of noise right, im goin nuts here. I can push down on the lifter with the rod and feel it spring back up

the adjust ment just doesnt feel right, no other valve feels like it in either the #1 or #4 position
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Monday, February 26th, 2007 AT 8:04 PM
Tiny
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Did you have the lifters out, I know you said in another post but I cant remember, if so were they and the pushrods put back in the exact location, im gonna see if I can get some more help here too

jim
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Monday, February 26th, 2007 AT 8:56 PM
Tiny
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Never took the lifters out, Im having to make repeated rotations as the lash increases, every time I think they are adjusted once I return to either 1 or 4, I feel movement in the rods, is this normal, repeated adjusting?
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Monday, February 26th, 2007 AT 9:10 PM
Tiny
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No that isnt normal at all, I wonder if they pumped down when they were out?That is the only thing I can think of that would do that, did you try going back to #1 with the valves closed and try the torque spec on the intake and exhaust and then try turning it over a few times and recheck
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Monday, February 26th, 2007 AT 9:51 PM
Tiny
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Hey Ron, Jim,

I found a little procedural info that may help, sent it to your emails, as if would be unreadable otherwise.
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Tuesday, February 27th, 2007 AT 5:20 AM

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