firstinlastout86

iTrader: (4)

So went to the track last week first time with the new Z last run of the night durring the burnout i bounced off the rev limiter.....after the run oddly enough my fastest 13.6 @104...noticed some ticking so i drove home and she has been sitting since. So yesterday i changed the oil to see it there was any metal shavings were in there. no shavings looked great..took off the valve coverand started removing the rockers and pr's so what do you think the ticking was?????? lol







so as you can see the PR shaved the hole in the head
what i want to know is it ok to just replace the pr with a new one and call it a day?

fleetmgr

No, it's not. The hole acts as a guide for the pushrod (same as a guide plate). You've got two options here...replace the head or go to guideplates all around.

firstinlastout86

iTrader: (4)

****...i figured the rocker / lifter would hold it where it needs to be since the pr doenst touch the hole(until you bend a PR)... so how does it "guide" it without touching it????

99RTA

iTrader: (-1)

NAAAAAA that hole is NOT a guide...put a new push rod in and be done with it. If the hole was a guide is would need to be hardened etc and wouldn't have worn in the 1st place........

99RTA

iTrader: (-1)

BS! why post info you know nothing about? These heads have bolt on rockers and don't need guide plates like the old small block chevy engines. How do you figure the holes were hardened????? The hole is there so the push rod has a way to get to the rockers.LMAO

where do people dream this stuff up?

NOBR8KSS

iTrader: (12)

Please don't replace the head. This is an extremely common occurance and that hole is by no means a pushrod guide. The rockers are aligned with that long metal plate shown in the first picture.
I personally bent 3 of mine about the same as yours...that was more than 60,000 miles ago. Replace the bent pushrods and you'll be fine. I'm sure you can find some used ones FS in the classifieds section for cheap.

firstinlastout86

iTrader: (4)

Ok I replaced them with 7.400 tsp's. I replaced all of them on the drivers side since I was in there will it matter that the stock pass side ones are a lil shorter 7.385 ish (from what I have read on here) I will be changing the pass side ones out this week when I put the cam is it safe to drive till then? Seems like its running ok now, thow I notice a little missfiring and theres a constant tick you can faintly hear(more clearly from under the car) that wasnt there before and every minute or so there it one loud knock/tick....

Also is it ok I just went threw with the torque wrench and put them all to 22ft lbs

99RTA

iTrader: (-1)

Well don't woory too much yet, drive it easy for a while and see what happens. Might be a noisy lifter.

You realize that push rod bent because the valve hit the piston? Its possible you might be hearing the valve.

02*C5

iTrader: (1)

Saw the link sorry I would also for good measure change the lifter. If it pushed the rod enough to bend it there is probably damage to the lifter. How is the rocker and the spring. Me you I would change everything to do with that cylinder. Some people might say no, but its your car your engine you pocket book.

greezy

bent? i win haha. hope when i replace my broken one it will run good

waterbug1999

iTrader: (3)

stock p-rod?

firstinlastout86

iTrader: (4)

yep stock pr's gotta love em...

LS1nut377

iTrader: (16)

yup sounds you may have some bent valves. my buddy in his m6 SS hit 2nd instead of
4th. and bent about 9 pushrods and slapped and bent every valve. replaced the pushrods. ticking and misfire there afterwards, turns out 2 cylinders were dead
and causing the misfire. replaced the heads and cam, got it tuned, problem cured.
good luck.

NOBR8KSS

iTrader: (12)

Well, according to your original post, you bounced off the rev limiter, which means you didn't mechanically over-rev the engine by the infamous "3 to 2" gear change. It's unlikely that you damaged the head (other than the wobbled out PR hole) by bouncing off the rev-limiter. The stock pushrods are designed to be the weak point (rather than the valves). If you do this with hardened pushrods, you will defintely bend a valve.

Without hearing the noise in person, it's really difficult to give out advice, but here goes:

Step 1: Finish changing out the pushrods. It's ok to run 2 different lengths for a short period of time since the lifters are hydraulic.
Step 2: Is the ticking noise still there?
Step 3: If yes, and you are getting a misfire code (SES light), then check the coils, wires, and plugs. Make sure they are working and make sure the wires are fully seated on the coil and plug.
Step 3: If you eliminate the ignition as the source of the ticking sound, then the next most likely culprit is a damaged lifter...most likely the one that bent the pushrod. Unfortunately, removing a lifter for inspection means that the head needs to come off.

Option 1: It sounds like you are doing a cam swap soon anyway, so maybe you should consider replacing the lifters at that time. Since you have to remove the heads to do that, you can inspect the valves for damage at that time. You will need to replace the head gaskets and head bolts as well when you do this, so be prepared to drop a few hundred bucks for that stuff.

Option 2: Replace the PRs and let it ride. The tick could go away on it's own after the lifters go through a few heat cycles.

Btw, 22 ft-lbs is the correct torque for the rocker arms.