Lifter tapping noise/sound, 5.3 LM7, after cam swap, oil affects, reference

New to LS engines, finally owned one for few years starting to get used to all the typical noises they make;
I recently did a cam swap, LM7. I never noticed any tapping sounds before that.
Engine is all OEM except cam/spring (PAC1218 & TFS-30602001 low lift, .560/.560 "slow" ramp)


After the cam swap I have 5W-30 synthetic Walmart oil in it. Didn't notice any tapping sounds for the first 1000miles.
Then I notice a slight tick. And by 2200 miles, it got louder, worrysome.
The oil looked like typical 'turbo/blowby' watery so,

I changed the oil to Mobil1 10W-40 and the ticking 'went away' after a few minutes of circulating that oil around.
I still hear it faintly. I suppose it sounded like that before and I just never noticed it until now.

Questions
What exactly is the noise? One lifter is bad or leaking down fast? Is the sound the lifter bottoming out?
Just one, or all of them?

My theory is increased spring pressure is bleeding down the lifters faster. It could also have something to do with pushrod length of course. And the thinned out oil isn't helping.
Real question is, is it safe to spin this engine 7k like this?
I'm going to measure pushrod length but overall I feel like there isn't much I can do. Many have replaced lifters and pushrods and still have some ticking sounds.

https://www.youtube.com/watch?v=azai69TxROM

thank you in advance, I normally don't even post when things happen, I just fix it first then make a video or post how it was done.
But this situation is different, some might not 'fix' it, just leave it be and see what happens, and the engine still goes 330k miles, but will it also do 600rwhp like this for a long time? And lets say it does or will be reliable. How much power is left on the table from the OEM pushrods? It could be 30-50hp so I think a dyno followed by exact length pushrods then another dyno is in order now.

What length pushrods? How old are the lifters?

oem length and oem lifters, presumably 150k+ mileage *unknown engine miles"

I would throw in a new set of lifters and hardened pushrods. Especially at 150,000 miles. And lifter trays, while youre at it.

yeah. the next engine I will unless this thing starts making bad noises sooner.
This motor was just a test to see how far the OEM stuff will go.

I really want a 4.8 or L33 for this car next, just curious how long un-gapped LM7 rings will last on 93 at 15-18psi etc...
on going experiments :D

I think its just one or two lifters tapping because 600rpm/60 = 10 times per second. Exhaust lifters working when intake lifters are not working, so you would hear ten times 16 noises at 600rpm and not just 5 if they all were tapping? Wait, I'm not sure human hearing works like that.
An engine idling at 600rpm can make a noise 5 times per second- but thats five times eight cylinders ignition events isn't it? So really when it comes to these audible noises there is no way for me to be sure. I would need some kind of acoustic analyzer, an oscilloscope and some hardware setup to detect the range of noises we are looking for or for narrowing down the noises in question to high resolution. Which is wayyy more work than just putting together a next engine with new lifters etc...

Anyways- it seems to be valve train related noise on just one of the strokes, maybe. The thing is, could it be every single intake lifter but not the exhaust lifters. Or just the front 2 lifters at the end of the oil galley. Or something weird like that. And I don't know if it has anything to do with the length of the pushrods or if the lifter is just bad, yet. Will update when I find out.

I've yet to find a gm ls engine that didn't make valvetrain noise. Most likely the noise was there before cam swap and now that you've done some mod's you're double checking to make sure things go well and you noticed the sound. As for the sound getting louder over time, my guess is the Walmart oil. I'm sure Walmart has its place in auto but Walmart brand oil is NO for me. If the sound starts up again, start digging in the motor. Pushrods first, look at the rockers where the contact the pushrods. If that doesn't help then go to lifters. Lifter replacement will require that the heads come off.
'

If you can pin down the noise to one side or the other, I'd swap rockers from side to side and see if the noise follows (nobody's mentioned needle bearings yet??). If the noise stays in the same place it's probably a lifter that was OK before, but the cam change put the plunger in a different position and it's no longer in its happy place.

Thanks, friends, its very good advice
hope you don't mind if I jot down my thoughts, this isn't necessarily a response its more like a compilation of ideas and thinking-ness so in the future when I look back I can see what I was doing or thinking &c

Honestly I would have instantly pulled the valve covers and checked for abnormal rocker/pushrod wear, but I am gun-shy now because I just had a rocker thread pull out of an 862 head. 22ft*lbs and two holes on the same head turned to melted cheese.
video of that happening:
https://www.youtube.com/watch?v=YcQ5aLebj68

So, risk of simply opening the cover and say, checking pushrod length (I just received pushrod length checker in the mail yesterday) just to do that one simple task has now exploded into an potential for having to replace another entire head and be down for 8 hours in my daily driver.
The mystery remains as to what caused that rocker thread issue. Hopefully it was just that one random head (previously owned of course so who knows).
Since this is my first LS engine I can't just say "oh wow I've done ten engines and never had a rocker thread failure" instead its "rofl my first head stripped it's rocker threads on the first engine, thats all the experience I have so far" if you see what I'm saying, perception is different now

Conundrum indeed. I suppose would take the car to a place where it can break down and perform the inspection (my father's house usually, hes got lots of space for my car to break and sit). I can't even work on cars where I stay during the school week let alone have one broken down there for any period. And I work at school basically 7 days/week, research example tomorrow is Sunday and am going to fix cell culture and decellularize pig esophagus for cancer research. I drive 180miles/week average (~13mpg if you know what I'm saying) so if something is terribly wrong in the engine, things will go south fast.


This is where we are at then:
I hear the noise from the bottom of the engine more, and barely through the top, and it's change with apparent oil viscosity, all is indicative of the lifter or lifterss. I am tempted to say that bad rockers and pushrods probably wouldn't significantly change in tone just from an oil change if there were any serious abnormal wear, debris, garbage. Also, we know that the OEM pushrod length is often not accurate for aftermarket camshafts and I have found statements such as this:

Quote:

---

"The rpm wouldn't warrent changing to the hardend pushrods, but going to a 7.400" hardend pushrod would give you an extra .005 of lifter pre-load back to help quiet the lifters. Not a requirement, but not a bad choice to use either."

---

on teh internez

also how many cars run an exhaust this quiet with similar camshaft that would would hear or notice a tick?

Impossible to say how many engines out there with aftermarket cams and oem pushrods share similar noises but the exhaust is covering it nicely.
Since I can't just pull the rockers to check pushrod length, and then order the pushrods and wait days for them to arrive, it will be impossible for me to check pushrod length. I need the car everyday right now lol. Reliable Tahoe engine, they said, never breaks down they said.

Should I just order 7.4" pushrods and slam those in AND check the length at the same time to get back on the road after an hour of work?
Or... just leave it and see what happens.

I want to dyno the car soon but now I'm worried about the lifters failing or forming debris. Many engines are available, I don't care about the engine so much as the turbo and cam which debris (bad oil) can take out with it. So my thought process starts with the turbo journal bearing, I find myself walking the length of oiled rotating bearing and working upwards through the feed line, past galley, oil filter, and back into the oil pan. And then I look up wards and see falling shards of metallic debris on the scale of 10^9 meters being formed at that moment, strewn throughout the crankcase without any visual or audible condition noticeable by human ears, yet. Which is actually kind of relief or assurance, in this case we DO hear a noise. And yet the engine seems to run fine and noise dissipates with engine viscosity (softer/less audible when cold).

In other words, if there was no noise at all. And everything seems fine. There could be a huge problem before we heard anything at all, much debris and trashed engine parts happen FIRST, that are then are FOLLOWED by a noise. The noise signifying that the destruction has been completed, all the damage is already been done. For example a spun bearing does not immediately knock; first, it spins, and then gradually over time the oil film dissipates and then metal on metal contact is established, and then finally you hear something, ruination completed.

So my engine has already been destroyed, and now we have this noise. Or. The noise has nothing to do with destruction of any parts and the engine is fine for the time being. Or a third option, I'm sure you can think of more possibilities, there might be ten or fifteen

Two cam related thoughts:
1. Lots of cams run a smaller base circle than your original. Even an original LS6 cam uses a smaller base circle requiring a longer push-rod or the changed geometry that the LS6 valves offered....no surprise if the aftermarket cam requires one of these options or an adjustable rocker. But if it is so minor that slightly thicker oil helps...

2. Lots of aftermarket cams use a more aggressive ramp that makes more noise for various reasons...and like you pointed out, a noisier exhaust often covers it up.

And another thought:
I've seen a guy suck the threads right out of an L86 block because there was some liquid down in the head bolt hole he was running the head bolt into (hydraulicced/hydro-locked it). That head bolt hole is designed for a lot more stress than rocker pedestals can handle. Don't know as I wasn't there but maybe that's all it was.

I would do two things.

First, if that torque wrench is a cheapie toss it and get another. If it's a good one get it recalibrated.

Second, I would start planning to put inserts in ALL the rocker holes. Put Timeserts in there and you will never have to give them a second thought ever again. (Heli-coils are just cheesy, don't like them, Timeserts are AWESOME AWESOME AWESOME.)