Just helped remove a 1.7 today and this is what came out of it.

There were probably 4 push rods that had varying amounts of this wear. I could make a guess at what caused it, but this end was seated in the lifter.

Just curious.... anyone want to guess?

Click to view attachment

wow that was close to failure!

the pushrod retainer spring was installed wrong and it has been rubbing.
Apparently for a long time.

Push rod tube retainer spring is installed improperly and rubbed against the push rod....for a while it looks like.

That is what I thought. But the end with the notch was opposite the end with the spring. All the rods with damage were seated in the lifters. I pulled the 1st one out and said, "man, I wonder what that lifter did to the push rod."

So the next guess is that someone did a tremendous dis-service and installed junk parts.

maybe that's someone's idea of lightening the valve train

Maybe the DAPO flipped them around when they noticed it?

That actually looks machined! Almost too perfect for rubbing on the retaining wire.

That looks like it was turned on a lathe. And it's not on the spring end.
Zach

That was turned on a lathe. Someone goofed on their geometry and started shortening the pushrod. The left cut is the same angle as the shoulder and the groove is the same length as the pushrod tip.
LOL!

If the lifter is doing its job right, it spins a little each time it moves. So the pushrods turn with it and this is what you get.

Nope, retaining wire got it.. It was probably inverted at some point by someone who didn't care, or didn't know any better.

The pushrod rotates as it reciprocates, which is what leads to this perfectly machined surface.

That looks like one "spirited drive" away from becoming 2 pieces

That just makes me wonder how much we could machine off the pushrods and they would be fine.
Every gram we take off the valve train helps

Just because it lives doesn't mean that it won't deflect.. Deflection costs lift and duration at the valve.

Turned on a lathe with a TNMG insert.

Click to view attachment

so.. you want to machine.
Titanium Nitride coated by vapour deposition.
tnmg is the code descriptor of one of thousands of configurations available.
the catalogs are great tomes too large to print these days so we download pdfs.
//http://www.sandvik.coromant.com//

Teenage Ninja Mutant Gecko?

Push rod tube retainer springs? I'm not sure what you're talking about.

Dual springs with stock rocker studs.. Playing with fire!

Playing with fire for 25,000 miles. So far, so good.