[6t7goat]

All ready ordered new guide plates form Ken K and will remove intake tomorrow to see if there is further damage. Hopefully not.

[Skip Fix]

FWIW the 3/8" Comp guideplates aren't too bad,been on my RAIV motor for a long time but did get tweaked for aligment. But definitiely something to look at the alignment no matter whose you use. Isky has some adjustable 2 piece guideplates but the slots aren't deep enough for a Pontiac.

[beemergary]

I'd sayn that bolt from being fatigued-stretched back and forth. I would check the slot in the rocker and what the other guys said. Got some rockers from crane and had a slot problem. You just can't check everything enough times. Had a 1/2" stud break down inside the head once causing the valve lash to get off. Thats still a mystery

[6t7goat]

Well I opened it up today and this is what I found. A destroyed lifter. The funny thing is the broken lifter is the one adjacent to the stud that broke. The lifter from the broken stud was in tact and just out of its bore. I did scope the cylinder and could see no damage to the piston. I could not recover all the broken lifter parts so I guess the engine will have to come out and be torn down. Man this sucks!!

[Region Warrior]

Hard to tell from pic's, but looks like lot of wear on 2nd one over.
Make sure the oil bands dont go past bore.

Agreed with WDC, get a set of poly locks.

[HWYSTR455]

Lobe is toast, you can see the angle of the witness mark on the ramp that would indicate the lifter tracked across the entire face, and before/after the peak.

When the cup popped, it probably got hung and damaged the lifter bore too.

Not fun. I feel for you.

.

[6t7goat]

lifter bore not looking to good.

[HWYSTR455]

The lifter plunger or body got hung between the lobe and the block, that's what caused that, as well as the lifter being chewed up. (And that lobe is wiped)

That's not particularly a problem, since it's on the outside, I was originally talking about the bore itself. That's what you need to look at.

Kind of moot at this point, you need to do a tear down and inspection regardless.

What kind of lifters? Do they have a wire-type retainer, or a snap ring? Should always go for snap ring type lifters.

.

[6t7goat]

The lifters are suppose to be Johnsons. Here are a few pic's of the one that was in the pbore with the broken rocker stud.

[LATECH]

Originally Posted by 6t7goat

Well today was not a good day for my 78 Trans am. I was out cruising and was at a stoplight and when the light changed I took off, not crazy but I was on it a little didnt even spin the tires. I heard what sounded like a backfire and it was all over from there. Here are some pictures of what I found under the passenger valve cover. This engine is a 74 400 block that is stroked to 461cu 4x heads screw in studs comp 1.52 rockers Tc-02 HF cam and lifters. The engine has less than 300 miles on it. What the heck happened? The screw in stud is broke clean off. I had to stick a magnet in the pushrod hole to retrieve the push rod I could barely see it. Check out the pics and let me know what you think. Thanks

It is also possible that the valve stem isnt oiling and the valve stuck. Did you check to see if it will open? I see rockers that may not drip enough oil on the valve to keep it lubed, also it is in the center of the head where there is the most heat, and isnt that an exhaust valve (more heat) I didnt ID it before I posted, that is why I posted it as a question.

[PONTIAC DUDE]

Those are Hilift Johnson lifters.

[jamaca85]

did the builder install the oil gally plug.......the one in the upper rear of motor, by the dist.