Hello, my name is jaros44sr and I have a problem...

[jaros44sr]

Well it all started several weeks ago and I'm at a loss...
Seems like #4 cylinder exhaust rocker arm is sitting askew compared to the rest of them! Don't think its a bent pushrod as I spun the rod and don't see any wobble, maybe a collapsed or sticky lifter. Could just one rocker arm be worn out or out of adjustment? Seems like all the nuts are adjusted about the same depth. If its the rocker arm Jeg's has stamped roller tipped (1.6 ratio) on sale till the end of June for 90 bucks. Maybe worn cam lobe, but always thought it was # 7 or #8 that was the problem

I've used a probe and don't feel any burr on the valve stem above the keeper, so I'm confident that this is something that just happened recently. Maybe I should pull the intake to get a better look

People said not to pay attention to it, but that is just not me. If something is differant, I think it needs some sort of attention...lmk what you think

SB 350 with a hydraulic cam, probably well used engine, but idk. I'm sure it needs a rebuild, but just wanted to get the restore done with this engine in it

Any thoughts would really help, I don't want to ignore the situation

[Arad68]

What is the compression in the cylinder in question? Is the rocker arm stud bent? Waht does the hardware look like on the arm...I.E. The ball and arm?

[LONGHAIR]

Askew which way? pictures? What year is this engine? Vortec heads?
The bent stud sounds the most likely from the discription at this point, but how would that have happened? The cam or lifter cannot effect the way the rocker arm sits, only the three points where it touches, the pushrod, the valve stem, the stud/ball can do that.

[jaros44sr]

Originally Posted by Arad68

What is the compression in the cylinder in question? Is the rocker arm stud bent? Waht does the hardware look like on the arm...I.E. The ball and arm?

Originally Posted by LONGHAIR

Askew which way? pictures? What year is this engine? Vortec heads?
The bent stud sounds the most likely from the discription at this point, but how would that have happened? The cam or lifter cannot effect the way the rocker arm sits, only the three points where it touches, the pushrod, the valve stem, the stud/ball can do that.

good thoughts guys, bent stud, didn't think of that!

Haven't done a compression test yet

Haven't disassembled, so the condition of the parts are yet to be determined

No vortecs, year about 80's, askew to the rear of the engine. Pics to follow

[jaros44sr]

2.130" outside demension on studs, #2 and # 4 cylinders

Please don't laugh at the condition of the inside of the engine, buildup was due to the PO running the engine with a leaking fuel pump

[GASoline71]

Looks like a lot of metal in the oil... I'd say some cam lobes are going flat.

Gary

[bigblock52]

Is the pressed in rocker arm stud starting to pull out of the head?

[jaros44sr]

Originally Posted by bigblock52

Is the pressed in rocker arm stud starting to pull out of the head?

didn't know they were pressed in, but that makes sense

[LONGHAIR]

It looks like a combination of a stud pulling out and a flat cam. All of that metal came from somewhere....and gas-diluted oil would be a good reason for a bad cam.

[red71cheyenne]

Wish I had some advice, but I'm just glad you found it now instead of running down the road several hundred miles from home!

[jaros44sr]

Originally Posted by red71cheyenne

Wish I had some advice, but I'm just glad you found it now instead of running down the road several hundred miles from home!

Thanks red



Well, I did some disassembly....seems like there is so much buildup the push rod won't move side to side, keeping the rocker arm locked off center

Studs don't look bent or pulled out, and pushrod is not bent

My question is, are all SB's the same size rocker arms and push rods (305 & 350), I don't know what engine is in there and search tool for your block numbers is to confusing to use. Possibly due to CRAFT

any thoughts, opinions?

[RustyParts]

You might want to check the stud Jaros, if that rocker has run like that for some time it usually cuts a groove in the stud. Good luck.

[stevencvn72]

Originally Posted by RustyParts

You might want to check the stud Jaros, if that rocker has run like that for some time it usually cuts a groove in the stud. Good luck.

Totally. You can see it here.





Happened to me! Pulled studs, tapped, and installed screw in studs. My rocker had eventually slipped almost all the way off the valve and was kind of jammed into the gouge. Had this in a couple of spots, some studs that were pulling, and a few bent push rods. I suspect the PO smashed the skinny pedal to the floor too often and too long.

[1949gmc]

Originally Posted by jaros44sr

My question is, are all SB's the same size rocker arms and push rods (305 & 350), I don't know what engine is in there and search tool for your block numbers is to confusing to use. Possibly due to CRAFT

any thoughts, opinions?

Hi Jim-

All small block Chevys, from the factory, have the same rocker arm ratio (1.5) and pushrod length (7.794 or 7.8). As far as the block numbers go, get the casting number from the back of the block or the suffix code from the front of the right bank, where the head and block come together. The casting number will be seven digits, like 3970010, and the suffix code will be something like V0629TBG. Post what you find and we can tell you what you've got. In fact, since you've got the valve cover off, post the casting number for the head, too.

Only things I can think of are the press in stud is pulling out or the rocker arm pivot ball is in upside down.... the top of the valve might be bent.... could be a worn valve guide, but that'd be a helluva lot of wear.

Have you ever had this engine running or have you heard it run? Post a picture, if you can, of those two valves from a straight on view.... what it would look like if you were leaning over the fender. I'd like to see those valves better.

Ray

[junkyardjohn]

Originally Posted by LONGHAIR

It looks like a combination of a stud pulling out and a flat cam. All of that metal came from somewhere....and gas-diluted oil would be a good reason for a bad cam.

GOOD ADVICE. IF THERES SIVER GUNK UNDER YOUR VALVE COVER, YOU CAN BET YOUR OIL GALLYS ARE FULL OF IT TOO. ALL THOSE LITTLE SHAVINGS JUST MULTIPLY LIKE RABBITS AS YOUR OIL CIRCULATES. THAT MOTORS LOOKS TO BE ON BORROWED TIME EVEN WITHOUT YOUR ROCKER PROBLEM. IT TAKE PLENTY OF CLEAN OIL FOR ALL THOSE LITTLE PARTS TO SLIDE OFF OF EACH OTHER SEVERAL THOUSAND TIMES EVERY MINUTE. JOHN

[GASoline71]

Only way to get all the particles out is to tear the engine down completely...

Gary

[jaros44sr]

Originally Posted by RustyParts

You might want to check the stud Jaros, if that rocker has run like that for some time it usually cuts a groove in the stud. Good luck.

After you mentioned that, I went down and checked. Sure enuff, a slot about an 1/8" deep in the stud

Originally Posted by stevencvn72

Totally. You can see it here.





Happened to me! Pulled studs, tapped, and installed screw in studs. My rocker had eventually slipped almost all the way off the valve and was kind of jammed into the gouge. Had this in a couple of spots, some studs that were pulling, and a few bent push rods. I suspect the PO smashed the skinny pedal to the floor too often and too long.

Do you have to drill out the stud hole, or can you just tap it after you remove the stud. Do you need a bottom tap

Originally Posted by 1949gmc

Hi Jim-

All small block Chevys, from the factory, have the same rocker arm ratio (1.5) and pushrod length (7.794 or 7.8). As far as the block numbers go, get the casting number from the back of the block or the suffix code from the front of the right bank, where the head and block come together. The casting number will be seven digits, like 3970010, and the suffix code will be something like V0629TBG. Post what you find and we can tell you what you've got. In fact, since you've got the valve cover off, post the casting number for the head, too.

Only things I can think of are the press in stud is pulling out or the rocker arm pivot ball is in upside down.... the top of the valve might be bent.... could be a worn valve guide, but that'd be a helluva lot of wear.

Have you ever had this engine running or have you heard it run? Post a picture, if you can, of those two valves from a straight on view.... what it would look like if you were leaning over the fender. I'd like to see those valves better.

Ray

Camera batteries just ran out, pics will have to wait a day or so

Originally Posted by LONGHAIR

It looks like a combination of a stud pulling out and a flat cam. All of that metal came from somewhere....and gas-diluted oil would be a good reason for a bad cam.

Originally Posted by junkyardjohn

GOOD ADVICE. IF THERES SIVER GUNK UNDER YOUR VALVE COVER, YOU CAN BET YOUR OIL GALLYS ARE FULL OF IT TOO. ALL THOSE LITTLE SHAVINGS JUST MULTIPLY LIKE RABBITS AS YOUR OIL CIRCULATES. THAT MOTORS LOOKS TO BE ON BORROWED TIME EVEN WITHOUT YOUR ROCKER PROBLEM. IT TAKE PLENTY OF CLEAN OIL FOR ALL THOSE LITTLE PARTS TO SLIDE OFF OF EACH OTHER SEVERAL THOUSAND TIMES EVERY MINUTE. JOHN

Broke a piece of the hard carbon off and using a magnet to attract the carbon, sure enuff it moved the piece slightly. So we do have a big problem ready for rebuild...but not yet

here's the block number
75B595801 KO6 24 CMJ
o
r
1
will post up soon, gotta get to work

[jaros44sr]

edited post # 17

[sinned4me]

Do you have to drill out the stud hole, or can you just tap it after you remove the stud. Do you need a bottom tap

on mine you pull out the old stud and mill the top of the stud boss to a certain height. it also depends if you are running guide plates. you then drill the holes on a drill press holding the head at the correct angle, tap the holes, and install the studs with thread sealant (there is coolant behind stud) and your done.

[jaros44sr]

Originally Posted by sinned4me

Do you have to drill out the stud hole, or can you just tap it after you remove the stud. Do you need a bottom tap

on mine you pull out the old stud and mill the top of the stud boss to a certain height. it also depends if you are running guide plates. you then drill the holes on a drill press holding the head at the correct angle, tap the holes, and install the studs with thread sealant (there is coolant behind stud) and your done.

Thanks for the info, was kinda hoping to do it on the engine. If that is the case, then I might as well change out to my extra heads

[wzuke]

Replace the rocker arm with a self aligning rocker arm.

[jaros44sr]

Originally Posted by wzuke

Replace the rocker arm with a self aligning rocker arm.

OK, I'm game...what's that and where do I get one

[stevencvn72]

I never even removed my heads. Pulled the old stud. And tapped the hole very slowly using grease and a magnet to catch shavings. No it's not the right way, but it can be done. Oh yeah, if you use shoulderless screw in studs, there's no need to mill down the stud boss. Just use thread sealer and jam nuts.

[GASoline71]

Old school way would be to "pin" a new press in stud in place. Insert new stud and drill a hole through the side of the boss and through the stud... then tap in a roll pin.

Gary

[jaros44sr]

Originally Posted by GASoline71

Old school way would be to "pin" a new press in stud in place. Insert new stud and drill a hole through the side of the boss and through the stud... then tap in a roll pin.

Gary

That sounds doable, so are you able to tap in the new stud with a 3lb brass sledge