Hi all - just curious, do screw in studs have to bottom out on the nut? I put some in a new head and screwed them till they bottomed out in the hole, but the nuts didnt seat onto the boss.. I found a rocker arm or 2 that was not sitting on the valve after getting a valve noise, never seen that happen before!

This is a stock i4 GM motor. Also - 3 push rods have about 2thou of a bend in the middle - im gonna re-check coil bind on the springs cos these guys use 1.75 rockers - also the rockers dont seem to have the ears like earlier styles - ive looked at numerous pics of new rockers and they seem to be pretty flat- so my other question is what would cause a rocker to move sideways off the valve tip?

Oil clean, motor fires right up - just heard valve noise and pulled valve cover to see rocker sitting sidweways!

 

Yes, they do. They'll eventually just fall out if they don't.

In many stock heads however, the intake ones in particular, will hit the outside of the intake runner, and can't go down all the way. You'll just trash the runner if you try to tighten them anyway. Only solution is to shorten the thread section below the hex, or just buy ones with a shorter lower section to begin with.

Sometimes you can get away with adding a washer or something but that runs the risk of raising the whole thing up too high; in which case the bottom of the rocker trunnion (or ball) might hit the hex, or not be able to go down far enough, or the rocker nut run out of threads, or the stud be so high inside the Polylock that the set screw won't go in.

In short, do it right, and don't try to half-a$$ it.

All that about "ears" and "flat" don't make any sense to me, the way you said it. No 3rd gen Camaro/Firebird engine matches that description. Although it sounds related to self-aligning rockers (the newer style) which have some sort of feature on the rocker tip that maintains alignment, which maybe could be described as "ears", whereas the earlier style used the push rod to guide the rocker, which in turn was guided by either a narrow slot hole in the head, or by guide plates. Likewise, our motors don't use anything that "seats onto the boss" after the manner of, say, Pontiac or Olds valve trains. You might want to find a forum where questions about your engine belong.

 

hi thanks - well this is a copy of the chevy2 2.5L/153 egine - its a real plane jane motor, thing is they use stock 1.75 rockers that are longer than the ones found on vortec heads - longer basically, wondering if these are "long slot" rockers.

ill check 2moro if the holes are not deep enough OR if the studs are not threaded all the way - either way - ive never seen a rocker jump off to the side of the valve!

As for the ears, i meant the vortec stock stamped steel rocker has ears on the sides to keep the rocker in place, this one doesnt - however the valve components look identical otherwise-