Hi All,
So quite a few years ago probably 20 or more, I had a 455 built by a local performance shop. Seemed to pull pretty well, although my frame of reference is limited. It has JM20-22 cam, forged pistons, C heads, Edelbrock performer, comp cams roller tip rockers. First pass at the dragstrip, something pops, pull it over, trailer it home. I knew the problem was pushrod related, but basically pulled the engine, sold the car, and the engine has been on a stand ever since. I'm looking into dropping it into my current Cutlass, but looking for some input and advice.

First...the obvious problem and damage;





Could this be as simple as they didn't use hardened pushrods? I expect I'll have to pull the oil filter to check for metal, what else would everyone recommend? If I can get this engine back in service without too much effort it would be great.

Thanks for all your help! (Is this likely to get more reading in the regular, big block section?)

 

Most likely you don't have hardened pushrods. If I remember correctly you cam has a max lift of .530. you should also check that the retainer is clearing the seal and guide.

 

Geometry could be off as well as needing harden push rods. Jmo

 

Did you check lift clearance. I had a similar issues bottoming out the retainer on the valve guide boss. Your rocker arms seem really low on the tulip portion of the stud. It might be binding at full lift.

 

Thank you everyone for the thoughts so far. I found additional clues.. Not good I'm thinking. I'll post pictures later. It looks like a lifter cup and some copper or bronze looking rings in the oil return.

 

Normally if the rocker sits low that means it’ll have more available travel not less. But they could still be binding.

 

If it sits low enough it will bind on the stud meaning not enough clearance rocker arm to stud if that makes sense. I had this issue with my previous sbo . At full lift it would get stuck the pushrod would fall down get pushed back up get cocked and bend. Almost the same way his is.

 

Ok guys, what are these pieces??? Do they help assess?

 

3 pieces of broken valve spring damper, and the top of a lifter.

 

So I'm looking at minimum, pushrods (hardened), lifters, and valve spring review. Should probably pull the intake and the oil pan since it's already on a stand.

I guess that's part of the risk of going to a shop that doesn't know Olds.. that was years ago.. live and learn.

 

The question is if you got a broken lifter , and chunks of the damper you had some clearance issues. Make sure your heads are good in that department.

 

I have similar guide plates and rocker arms. Dick Miller has a great set of pushrods. He supplied them for my build. 3/8 .083 wall hardened chrome molly, oil restricted. In order to obtain the correct rocker arm geometry, I had to go with a shorter pushrod than I wanted. Had clearance a small part from the lower part of the rocker arm so it would not rub on the rocker stud. Use the checker springs and you can feel if you have any binding. Picture shows crimp type lock nuts. They messed up the threads on the studs so I had to buy a new set and ended up using CC poly locks. Much better solution and they fit within the stock valve cover.

 

Sounds like I have some homework to do. Valvetrain geometry 101 coming up. Homework, then clean up the garage enough to start disassembling things.
I'll post as I learn more.

 

Maybe my sense of scale is off. To me, those look like the metal retainers for valve stem seals.

 

If you end up needing 9.2" push rods, DM me. I mis-measured and ended up with these from Smith Bros. A nice set of 3/8" oil restricted push rods. I'll make you a good deal on them.

 

Sounds good, I'll keep that in mind.

 

I agree with Schurkey. Check your retainer to valve stem seal clearance at full lift!

 

Im guessing the metal retainers on valve seals somehow broke and wedged in valve spring. Maybe from retainer bottoming out at full lift. Lifter and pushrod had no place to go so it bent and collasped lifter and broke it. Hopefully it did not hurt face of camshaft lobe.

 

I don't think the lifter ever collapsed. Just the opposite--it "pumped up". I think the non-hardened pushrod let go after pounding the retainer against the valve seal, and there was enough oil pressure to pop the pushrod socket out of the lifter, because the frail lifter spring-clip couldn't hold it in place once the pushrod wasn't pressing down on it.

 

Thanks guys.
​​​​​​ So if that's the case, hopefully the cam isn't damaged. Would it be appropriate to replace only one lifter, or a few if I find the same situation on the other cylinder head?

 

You'll want to find the pieces of broken spring clip.

 

How did that lifter cup get up in the cylinder head? And where is the spring clip that tried to retain it? Hmmmm.

 

All I've presented so far was found under the passenger side valve cover and the oil return passage on the head. I plan to remove driver's side and investigate, and then eventually the oil pan.
Since I shut the car down after the pass down the 1/4 where it popped and trailered it home, I'm hopeful I didn't break too much and that I can bring it back to life this year.

 

I guess if the oil filter is still on it, I should cut it open and investigate that also....

 

Ok, was digging into this today. Lifters are ok. That piece is from the tip of the valve of the bent pushrod, not the lifter cup. For some reason the neighboring pushrod is bent not from thinning out on the guide plate.



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