Firebird is down for the count...
 

I took my valve cover off to get to my broken rocker arm stud today( i was going to fix it) and i notice a rocker arm stud thats loose as hell... I look at it. The push rod is gone.. I dropped a lifter.

Yay.

Ls1 swap time....

you could have broke a pushrod too and the cam be fine, if you cant see it. Ive done that before, i would tear off the manifold and look at it.

But what would make a rocker arm stud break and a pushrod break at the same piston? thats whats confusing me, Its all the same piston..

well you had to have some collision in there obviously, i would tear the manifold and the head off of that side and see whats up with it. Only way to find out is to look.

The pushrod is gone as in missing?? Can you take a pic?

yeah i don't get it. is it a different rocker than the one who broke?

Its a different rocker, but the same piston..

Im guessing, either, pushrods are too long, or something serious happened...

hmmm... don't get down man. i went through it too, its part of the game but IMO its well worth it. i don't have anything constructive to say besides that. best of luck

So the pushrod is GONE?

http://i13.photobucket.com/albums/a2...84/nothing.jpg


GONE.




edit. progress
http://i13.photobucket.com/albums/a2...84/motor-1.jpg
I need to get the distributor out. and then I can pop the intake off. I don't know how to get the distributor out, because i got the hold down off, but i couldn't figure it out..

the passenger side head will be coming off.. no matter what

What kind of pushrods where they?

what kind of rods were they? your upper part looks awfully dry in there, did you clean that or has it been sitting a long time? i would just rip the manifold off and see whats up. I am betting you broke the pushrod, if you sunk a lifter the rod should still be somewhat visible as enough of that should be coming through that head. best thing i can suggest for the future is chrome moly pushrods with thick walls and a 5/16 or 3/8 size

What size do you need?

I don't know. Ill find out when I figure out what the problem is..

the push rods I used might be too long...

cant wait to work on it tomorrow night...

I have a set of 7.138 I think if you want em.

Why are you guessing? Thought there was a shop you found close to you that would work on it?

Since you are talking about both being on the same cyl, I have an idea what most likely happened.

When the stud broke, it most likely created excess cyl pressure that the valve struggled to open against, the pushrod was the failure point.

Get the intake off, pull the pieces of push rod out, put the new stud and rod in, hand cycle the engine with a friend there and keep an eye for a hung up valve since that could have caused the initial stud failure.

-Tim

I got one peice of the rod out. its bent and broken. the other piece is located and ill need a magnet for.

What do i look for a hung up valve and how do i cycle the motor by hand.

yea, sounds familiar, i have a push blower that loves doing that, it'll snap them like clockwork, i keep a few spares and i have it up a running in no time.


matt, theres a tool to check for proper pushrod length, shouldnt be too much iirc, i say invest or borrwo one, read up on how to use it, may take a few days and a few questions, personally i never used one so i dont even know how to, and then chekc to see what length pushrods you really do need. once u have that, measure your current ones, you may need new ones or just replace the broken ones and keep that size. either way, since its that same cylinder, id go with tims diagnosis on this one. you may not need hardened pushrods or anythign special if just that bad rocker arm stud caused it, thatd probably even F up a chromoly one too.

chrome moly ones will snap too, ive had .080 wall comp cams ones snap. I had a set snap when i dropped a valve, but all the other 14 are originals since 03'

So how do I fix this problem? take the head off and get it rebuilt? or what? These are $450 GMPP vortec heads and with the right manifold and, screw in studs and springs I could easily have gotten better heads for the price...

the more i think about it, u should check to see if the piston in that cylinder in question is still connected to the crank. in theory it could have came up and wacked the valves, popping out the one rocker are stud and breaking the other pushrod. basically youd wanna drop the oil pan and check the rod cap and bolts are all there on that piston in question.

Thats way beyond my ability to take a part and put it back together... I honestly think Ill be able to put the intake back on and get everything working again, if I could get some help or good advice on the distributor and timing..

but pulling the oil pan is out of the question. The oil pressure seemed pretty normal when I limped it home, maybe a little lower then normal.. Temp was fine.. We will find out when I can get the rest of the pushrod out of the hole it fell into. and I put it back together, if its fixed or not..

What you will want to watch is that each valve opens and closes smoothly, no sticking or anything. I really doubt there is any need to send the heads out for work if they are fresh from GMPP. Did you buy them directly from GM? If you bought them new, you shoudl shoot GMPP an email and see what they say about the stud failing and related pushrod failure.

You can cycle the motor by hand using a longish break bar or ratchet with a cheater bar on the bolt in the center of the balancer.

-Tim

I bought the heads from jegs last year and had screw in studs and new valve springs installed by larry hansen. Im gonna go to his shop some time and see what he says..