All I can hear on mine is the intake sucking in air. That's with ws6store max effort rockers and 2116 lsr lifters at around 40 thou. All pushrods same length in the 7.8 range. Long tube headers as well which usually amplify noise.

 

Pop off covers make sure everything is torqued again and the rockers are aligned as straight as possible with the tip of the valve and call it a day.

 

Well, one of the guys I talk to at the local cruise puked a rocker arm roller bearing on a 30k mile car(stock).

 

I have used the CHE kit supplied with a plastic "rocker arm" to check for correct pushrod length.
Did your kit come with that tool ?

 

On idle it sounds normal but once rpm increases it sounds like something isn't exactly right correct? I decided to go out and record a clip of the 01 to see how loud the valvetrain was but certainly not an apples to apples comparison.

 

My kit did not come with that.

 

I really shouldn't hijack this post, but how important is matching the original rocker arm to the correct valve? I bagged and tagged each one, but may have mixed a few of them up. By the way, I replaced each push rod when i did the CHE upgrade. Car sounds great and the dyno tune went smooth so I'm not overly concerned....yet.

 

I don't think it's super critical on the rocker arms. Are we to assume the wear on the pushrods, valves and lifters are identical?

 

It's a good question. I think by changing valve spring, rocker arm, retainer, lock, etc. it will change wear pattern or characteristics anyways.....When I upgraded to the CHE trunion kit, I inspected each rocker arm to see if the wear pattern was normal looking. Most were in the center where you'd expect, a few had wear patterns a bit off center, and one had a wear pattern way off. I'm almost 100% certain that this rocker arm and valve was matched up as they were originally. It was on the passenger's side where I may have mixed a few of them. When I replaced everything, it seemed as if all the valve stems were sitting 100% (as far as my eye could tell) centered. I can't explain the anomaly, but after rotating the engine over and over with the new hardware, everything looked good and everything was opening up and located as it should.

One thing I noticed, and I don't know if this is ever talked enough.......when i upgraded the springs and retainers with new locks, the retainers I used reduced the clearance between the rocker arm and the retainer itself where the space between the two was paper thin. My fault since I mixed and matched springs and retainers. I bought pac retainers to go along with the pac 1218x springs and I was happy to see a little more valve stem tip poking out of the retainer increasing the clearance. I also took out the new comp cam valve locks and reused the original stock locks. It also increased clearance by a hair. I couldn't believe that the comp cam replacement locks for the ls1 moved the retainer up (albeit a very, very tiny amount).

So I wonder if the issue he's experiencing is trunion related or spring related.......

 

I have the CHE kit.

I grabbed random rockers I had lying around from a 5.3. Installed them in random places. Reused in different cylinders heads. Never checked the wear pattern. Used only with 0.660" lift rated dual springs. Swapped from steel to titanium retainers at some point on the same springs. Rev'd the engines to 7,500 rpm all the time, even dyno'd it like that. My removal and installation of the rockers involved an impact gun and excluded tightening the rockers while cam is on base circle for said rocker. I never measured pushrods or preload and just threw in 7.400 5/16 pushrods. None of the 4 engines I put the rockers in had any strange noises. I actually have those rockers waiting to go into yet another 5.3.

If the noise is that bad, could it be possible that its an installation error? or something not even related to the rockers?
Maybe something wrong with the rocker pedestal? Oil change with 20w60 right before? Is there oil in the engine? Do you have good oil pressure? Are all the pushrods actually aligned inside the lifter? Rocker bolt is stretched? Crank pulley is ATI/Fluidampr and outer bolts are loose? Exhaust leak? Forgot to put a lower washer for the valve spring?

Stock lifters and pushrods are fine with the bolt on basics like a mild cam and .660 dual springs. You only need to upgrade them for power at higher than stock rpm.

Check all the silly unrelated things first then go back and pretend to do the installation again.

sewing machine noise is kind of normal though with aftermarket valve springs

 

I'm in a similar boat with the same noise. It's not as noticeable in videos as it is in person, which it is loud enough to cause concern. I'm at the point of thinking maybe my Smith Bros trunnion bushings are bad/damaged during install (replacing with stock rockers to test when I get back to my truck), or else both sets of my ls7 lifters are junk and I need to replace.

 

I was very careful with install and am very meticulous with this type of thing. I opened it back up and removed about 10 rockers. Rocker pedestals look fine. Running 5/30 synthetic but going to run 0-40 (one post I read said this nearly eliminated noise), oil pressure is fine. I double checked all rocker nut torques after rotating engine by hand a few times and they were still fine when I removed rockers the other day. Rocker bolt could be stretched I guess, but likely 1st time off and engine has 50K miles. The heads did not have a lower washer - just the seal that acts like a washer. I did replace valve seals while it was apart.

I measured pushrod length using a Comp Cams adjustable p rod and BEFORE preload, I came up with 7.325 on all four corners. So, I just ordered 7.400" p rods which will give 0.075 preload. My understanding is the stock units on the LS6 are actually 7.385" long. I'll install those Saturday (if they arrive) and will post an update.

The noise may be normal and quite a few C5 Z06 owners have complained out this but others say their engine is extremely quiet even with aftermarket springs. Who knows. Still much quieter than my 383 with Comp extreme flat tappet cam and that engine has been together for 20 years. If pushrods and oil do not make a difference, I'll swing by a GM performance/tuner shop close to my house and let them listen to it.

 

I know I am poking randomly at the problem but you might instead notice something I didn't mention.

Stretched bolts are easy to find. Highly unlikely you have this problem but its worth a try. I have never stretched a single rocker bolt, ever, and I use an impact to set down my rockers.




Check not just the individual pedestals on the rockers, check the whole rail. maybe something got stuck underneath.
So what you are saying is the new valve seals were like the old valve seals, and the lower spring washer is part of them?

Yea stock pushrods are shorter than 7.400.

~0.075 pre load on stock rockers works. Some do the rocker bolt turn method; 1-1/4 to 1-1/2 turns You count turns of the bolt after rocker makes contact (zero) preload with pushrod while tightening to 22 ft/lb torque. It is not a better method, its just a way to double check actual measurements.

No check engine codes? Misfire stuff, bad coil wire?

 

Stock OEM pushrods are around 7.380

.079 preload is 1 full turn.

So 1-1/4 to 1-1/2 is going to be pretty close to .100 - .120 of Preload.

 

My bad, I have been using .120 or less for preload on stock lifters.

 

Update. The slightly longer 7.400" pushrods, with a tad more preload, made no difference in noise.

I then removed the PAC 1211x springs and installed 1218x springs. The 1218x's have 10lbs more seat pressure, but open is 328 vs 370 compared with the 1211x. Spring rate is significantly less as well at 313 vs 385. I also switched from 5-30 to 0-40 oil.

The noise... Slightly reduced. I'll chalk the noise up to "normal" for this engine and still much less than my small block with aggressive flat tappet cam, roller rockers, etc. I'll sleep better with the lighter spring rate lol.

Again, the trunnion upgrade was my initial concern because CHE said more noise would be notable until pushrods were updated.

Wanted to update/close this out so that people would not be left hanging. Thanks for the input everyone.

 

Appreciate the follow up!
Ron