Dicecal

Comparing the 2, the HS seemed to have a bit less friction when rolling. Nothing scientific, just my own personal choice. The CHE's look nice and roboust though.

Dicecal

good news

Undy

Typically a needle bearing rocker takes less pressure fed oil to lube it's bearing(s) that a bushed bearing rocker. I've installed oil restrictors in other engines when I'm changing rockers the other way, from a bushed bearing to a needle bearing. I'm wondering if there'll be long term wear issues with the CHEs due to that?? Just asking ...

Davesz06

Got car back last night, tech (ken) found bearing cup and more needles, still missing 10 but he said drive it thats what its for.

jbp8653

you probably lost some when you drained your oil. There are probably some on the oil sump pick up tube screen. We found a bunch there when they did mine last year. There is no way they can get past screen and into your motor. GM knows this and that is why they do not tear into motor to search for stray bearings. I raised a stink and they finally agreed to drop oil pan and check so I seen it for myself. We didn't find nearly all the bearings on mine either and its been over 10k miles with no issues.

Davesz06

Had Z repaired at Saxon Chevrolet Elk River MN. Happy with their service dept and Ken the tech that did the work, would have liked to have oil pan r and r to see the oil pickup myself but I guess you can't always get what you want, still short 10 needles but I am going to drive her like I stole her but I won't beat her like a rented MULE.

KGjevre

stuff still comming out from the 2 broken rocker arms or a new broken one?

CanadaGrant

Time to pull the valve covers...
Good luck!

augydog

And after all this time.

I feel your pain.

Hopefully it's the old stuff.

Good luck on it.

Jim

QIKSLVR

This may be a dumb question but what is the difference between the V.1 & the V.2 HS rockers?

I have an '07 Z that I bought used w/6,000 mi on the odo. It was delivered new in September 2006. Although it wasn't built between the dates advertised in this thread, I don't think you can ever be to cautious.

Bigbucks

Absolutely. While it pretty much appears that there was a 'bad' batch of rockers at some point for '07 motors, it is also true that the intake rocker design is marginal. This is proven by the fact that virtually all of the failures are intake rockers. If it was totally batch related, then you'd expect somewhat of a 50/50 distribution, but it's more like 98/2.

So anything that affects intake rocker quality is likely to result in a failure. It is prudent to check (or replace with something better).

Dicecal

v1 have INA bearings, which have been failing. v2 have timkin bearings, hopefully no more problems

jbp8653

After all this time???? Didn't you replace all of them back then when you had your problem? How much do you drive your car?

QIKSLVR

Another stupid question. I know what needle bearings are however I don't know what INA bearings are nor do I know what Timkin bearings are. Does anyone have a picture of these type of bearings that display the difference?

ronsc1985

Just different manufacturers. The basic design is the same.

CanadaGrant

Same bearing size. Just slightly different compounds from a different manufacturer. There has been the odd example of rocker bearing failure outside of the "bad batch" in the first part of 07 but I would bet that since then there have been more total engine failures than rocker failures and that wouldn't be too many. I have an 07 that falls in the suspect range and I pull the valve covers for a look see once in a while but am not really worried. Good excuse to have a cold beer and turn a wrench though...

KGjevre

Yes, all were replaced, but they were in limited supply at the time and came from several places, which I was not happy about at the time because I thought that some could potentially be from the bad batch.
The initial falure was discovered a bit before 4K miles and I am now at a little over 8K miles.
I will ask the dealer to have a look under the valve covers and we will see if it will be on my dime or GMs - does anyone know what the ballpark charge would be to remove the valve covers for a look?

CanadaGrant

1.5 hours would be more than enough time for removal and inspection. I do it myself in less than an hour as I like to stay away from the guy at the local dealership with the greasy hands and the big screwdriver sticking out of his back pocket...

bowtiguy

instaled my CHE's at the end of april. 1,000 or so miles since ( including one 4 session track day) . valvetrane has never been quiter. Had to pull the heads for cometic sealing issues ( unrelated) so I had a chance to..

1) check the trq on the rocker bolts..all checked out fine at 22 ft/lbs ( BTW, I did not use the rec: torque rotate engine retorque method)

2) pulled the mounting bolt out of each rocker assembly and spun them in both directions...smooth as glass, with VERY little lateral play.

I "had" the INA bearing H/S rockers. Randy Sr. sent them back with the reworked timkin units. I sold teh rockers but kept the INA bearings. I'll take pics for you guys when I get back from the great land ' lincoln.
They definately ranged from the good, the bad, and the ugly

At $695 outright a I bought a completed set from CHE, sold my H/S for $400, called it a day. Not that I didn't trust the Timkin H/S rockers, it was a down time issue with the car.

jbp8653

Well you drove 4k miles since you had the problem. I'am assuming this is your first oil change since then. It surely could be from that time but it would be easy enough to pull covers just to be sure.