Pulled the Valve Covers.. FOUND THE PROBLEM *EDIT: stud replaced*

[tlspeed]

I think you have a bad cam. A friend of mine had a SB400 with the same problem, All of his rocker were loose and one even fell off when he was messing around with them. We put a new cam and it was good as new, even ran better, imagine that. IMO put a new cam in. -Troy-

 

[1-ton]

how do I know if I have hydro of solid???

There is a 99.99% chance it is hydraulic. You will almost never find a solid lifter set up in any engine you come across today, unless you bought an engine from somebody that used it for the express purpose of racing.

 

[Russell]

Holy crap boy, thats some major play, and garunteed to be your problem!

I'm amazed it ran at all!

That video you sent me the other night, I just looked at it again. I figured that noise was the straight pipes, but now that I've listened again, I can tell that is just some massive clacking from the valvetrain

If it winds up your cam / lifters is wiped -- I've still got that stock cam avaliable.

 

[CB77GMC]

How where they that loose and you not hear it I will never know.

 

[danny7139]

Well it can be alot of things. First I would check for metal shavings in the oil. That should elimnate the cam theory. Check to see if all the rocker arm studs are on the same plane. To check the push rods for straightness take them out simply by moving the rocker over and pulling them straight out and wipe them off, then roll them on glass and see. I doubt all the lifters failed. But you never know till you pull it apart or adjust the rockers. To adjust the rockers correctly, follow this guide. http://www.73-87.com/7387garage/drivetrain/valvlash.htm

 

[4xcrazy]

How where they that loose and you not hear it I will never know.

I do not believe he is a top notch mechanic, he probably just hears a bunch of noise, but not really knowing WHAT the noises are, unlike those of us who know more about the engines and what noises certain things make when they go bad,,,not talkin crap about him, but he has admitted that he is not high on the "mechanical totem pole" "pole" sorry dude

i have chatted with him on messenger quite abit, and tried to get descriptions from him, but we all know how that goes through the internet


James, you asked me for advice and options alot lately, and i only wish you or i were closer to help ya out there, i do know, that if i could have heard the motor in person, i could have helped you pinpoint this problem,,,they do make alot of noise,,,so put that in your notebook,,,
"this is what loose rocker arms sounds like"

and to kinda fix my previous statement, about the "known bad motor" i am kinda thinkin ( after reading PM's and emails) that the seller most likely really didn't know much about the condition of the motor, and the way it ran, but did not intentionally sell a bad one.

anyhoo, i am always here to try to help walk ya through and repairs or fixes.

 

[78Suburban]

from the moment I first turned the key, I heard a pretty substantial clacking. I haven't dealt with enough engines to really diagnose noises. I asked people on ck5, and they said "alot of chevies tick". Search my name and posts and you will see I said it was ticking.. From the moment I drove the truck I heard clattering and had it backfire through the carb at over 1/2 throttle.. I had just ruled out internal problems, because I was told the motor was good For those of you who know who the seller is, he's offered to make it good. He's gonna send me a new cam and lifters.

 

[78Suburban]

More pics... Bad Stud, bent pushrod

Ok, I just pulled that wicked looking rocker. I can try to push down on the pushrod, but I don't feel the lifter give at all Maybe I really do have solid lifters? I looked at the pushrod, and rolled it on glass, and she has a bow in her for sure. The pic doesn't capture how bad it is, because I can feel on the backside of the stud, and she is worn almost 1/4 of the way through.. So I guess I'm going to have to tap a .003" oversized stud in with a hammer, or simply tap some threads in the hole and get one of those screw in studs. I can't tell if the stud is pulled loose from the head, I guess I would have to pull all the rockres and put a straight edge across the studs. The top of the exhaust valve seems to have a little wear, but I don't think I'm gonna try to worry about that. The main thing is that I figure out what went wrong to bend my pushrod and wear this stud out, it has a groove cut in it. I can get a new stud, and take a rocker and pushrod off my old 350, but if the same problem is present, it will just happen again. I wonder if a dead lifter or flat exhaust lobe would run a high chance of cauing this type of problem?

What do I need to do next? I know replacing the stud is in order, but I must correct what went wrong before it happens again. The other rockers don't seem to be as loose as this one, just a little side to side play, which makes me think maybe they can just be adjusted.
thanks,
James

 

[78Suburban]

another video

Here's another vid I forgot to post the other day, when I pulled the valve covers. I had all the plugs out of the motor, and was getting a buddy to just turn the starter over so I could see if anything looked like it was not moving.. Can yall tell anything from this vid?

 

[kgblazerfive]

The push rod could be bent because the rocker was loose as well as the stud having a groove worn in it. All the wear that you see is from the rocker being loose. The stud should be fine to a point and you decide what that point is, I wouldnt worry about it. I would find another push rod and rocker and put it back together and see how it runs. Then look into fixing the stud if your not comfortable with it having the groove. If it doesn't work and you find a flat cam then I would fix the stud also. If that rocker was loose you may have others check them also. If it runs the loosen till it clatters then tighten till it stops then go a 1/4 more is how you do it. If it doens't run then top dead center on the cylinder and tighten till there is some drag on the push rod then a 1/4 more works. You should be able to tell if you have a flat cam by watching the rocker move. You cant compress a hydro lifter by hand when it has fluid in it. The wear on the ext. valve is from the rocker being loose don't worry about it. There is a difference between a tick and a clack yours was clacking they all tick.

 

[neverendingproject]

Its gonna be your stud, Stud pulls out, and has a longer arc, causing a bent pushrod and all sorts of fun. Ive seen this happen before and it is the SOLE reason I went to screw in studs.

There is no "problem" to fix because studs pull out sometimes. It sucks, but it happens. Im sure that your lifters are fine. Just get a new pushrod, lifter and either fix or replace the stud and pin it in place so this doesnt happen again.

 

[78Suburban]

well, I've got another 350 full of rockers and pushrods, so I guess I can swap another one on.. I'll try to adjust them all by hand, since they're probably way off. then I'll try to fire it up and do them with the motor running. I'm gonna use this website to figure out which ones to adjust when it is TDC on compression or exhaust.. I'll just spin them around till I feel drag then go some more.. I've heard 1/4, 1/2 or 3/4 turns. I'm going to do 1/2 I think. then I'll try to fire it up and adjust them with the motor running. routing the plug wires and keeping them out of the rockers may be a chore. So this whole problem could have been caused by somebody adjusting the valves way wrong? I wish I could take a pic of the back of the stud, the groove is pretty uncomfortable deep.

guess I'll use this order for adjusting
http://www.thedirtforum.com/chevyvalves.htm

 

[pvfjr]

You want to adjust a valve when it's closed, so that would be TDC on the compression stroke. Sounds like you may get this thing going soon. Good luck with all that.

 

[78Suburban]

So is there a fool proof way to tell if a wiped out cam lobe caused this? It would really be nice if I'm not in for a cam swap.

 

[1-ton]

So is there a fool proof way to tell if a wiped out cam lobe caused this? It would really be nice if I'm not in for a cam swap.

One way would be to turn the engine over, with the valve covers off, and watch the push rods go up and down. If all the push rods are noticably going up and down, then the cam should be OK, but if you see any push rods barely going up and down, then you have a flat cam lobe.

 

[78Suburban]

One way would be to turn the engine over, with the valve covers off, and watch the push rods go up and down. If all the push rods are noticably going up and down, then the cam should be OK, but if you see any push rods barely going up and down, then you have a flat cam lobe.

do they look ok in the super short/junky video on page 3?
thanks

 

[1-ton]

do they look ok in the super short/junky video on page 3?
thanks

cannot see enough on the video to be able to clearly tell you anything, other than the rocker arms where definitly very loose.

 

[78Suburban]

Right now the game plan is to buy a slightly oversized stud at tap it in. Dorain # 693-005. The napa part number equivalent is CEP-2141011. It costs a whopping $1.70. Gonna pick it up today, pull the old stud with a nut and washers. Probably freeze the new oversized stud, and double nut it, tap it in with a hammer. Then going to adjust all the valves with the motor off. Then fire it up and adjust them again with it running. If all goes as I hope, this should work. I'll just steal a pushrod and rocker from my old motor I know that the rockers were lifting up and down when the motor is turned over, so maybe the cam and lifters are still good. I didn't see any just sitting there. Lets hope its just a matter of replacing this stud and adjusting all the valves. If so, I'm gonna be one happy camper I'm really starting to learn more and more everyday from this site.

 

[sweetk30]

2 things.

1 you need to cut off some of the stub boss if you go screw in studs . lots of work for you .

2nd thing. if the push rod was bent also check the hole in the head it passes threw and look for wear as if it is to big it will allow the new push rod to bend also. if it is to big there is a old trick you can try. find a pieice of brake line that the push rod will fit in and use it as a sleave on the push rod to take up the play in the head. i saw a old 305 run for over 10k miles like that . only reason it is not still going is a rod threw the pan from lack of oil in it.

 

[1-ton]

Right now the game plan is to buy a slightly oversized stud at tap it in.

If you think what you have been through already has been a nightmare, then you are really in for one, when you attempt to remove and install a pressed in rocker arm stud. I can do a lot of things on my own at home with my trucks, but even I would not attempt to take on a pressed in rocker stud (or studs). I have watched machine shops remove pressed in rocker arm studs from Chevy heads before, and even for them with all the right equipment, it was still a somb!tch of a job.

Your best bet is to go find a mass supplier of rebuilt engines, and for about $1200 (with your engine as a core) get a rebuilt one.