Fast98Z28

I started hearing a ticking awhile back from my drivers side head, and after inspection of rockers, valves, pushrods, and bearings all looked good. So I decided to put everything back together. Started it and the noise was gone.... So I let it warm up and took my mechanics stethoscope and put it down by the lifters on the head and could hear "tick tick tick" lightly. I then went to the other side and heard the same noise from the exact same spot on passenger side. I could only hear it when using the stethoscope. The engine/trans itself only has 2k miles on it. It still has not seen full throttle. Could this be a sign that I need more preload on the lifters and need to go with longer pushrods? There is a significant amount of valvetrain noise, but just like a LOUD sewing machine.

Engine is a rebuilt LS1, TSP 228R, Comp beehive springs, new lifters, 7.4 pushrods. Cometic head gaskets, stock rockers.

bluenightmare

welcome to the ls1 valve train. I did a fresh build 2 years ago and my lifters got loud enough for me to tear my engine back apart and look at everything. I sent all my lifters, cam, pushrods, rockers, springs and heads to get check. They all checked good. I put everything back together and the noise was still there. I have hardened steel 7.4 pushrods and I have checked preload 3 times on all valves duing break in. It has been 2 years and 30,000 miles later and it is still going strong. The tapping noise has gotten quieter over time. I can really hear it when it is cold out, once it warms up it quiets donw and the only way to hear it is the stethoscope. I take this engine to redline at least 3 times a week getting on the highway and have no worries.

MyFirstLS1

iTrader: (8)

https://ls1tech.com/forums/general-m...p-reached.html

anything like this ?

Fast98Z28

nothing that bad. Heres a video of what it did originally after 2.2k miles on fresh rebuild.



Since then I have checked everything other than taking the heads off and it seems I may need longer push rods. I put everything back together and didn't hear the noise initially. I drove it down the road and back and it came back slightly but not as nearly pronounced as it was. I will get another video of it tomorrow. I have checked pushrod length thinking they may be too long, but after measurements it seems they may be too short. I ordered some 7.425 PR's and see if it gives the proper preload it needs. Apparently the 228R has a smaller base lobe than stock. So it would make sense. I used the comp cams PR tool. Has anyone had this similar situation?

Fast98Z28

Well I installed my 7.425 PR's last night. And truthfully it sounded about the same... I can hear slight lifter tick all over the heads on both sides when using a stethoscope. I gave it a few revs and as the rpms come up it feels rough after 1500 rpm. Is this normal for a cam? It felt smoother with the 7.4's. Im not sure if the 7.4's were correct or i need shorter pushrods.
I have measured countless times but it seems as if I needed the longer length pushrods. Then again this would be the first time i have ever measured pushrod length. So maybe i am doing it wrong. Any input would be appreciated.
Thanks

Zmg00camaross

iTrader: (11)

Well the scope is going to magnify any slight noise. You could do it to any engine and your going to hear valve train noise. Sounds pretty normal. Now if I lifted was knocking I say sounds like there would be a issues. Hell putting a fast intake on my car and the Valvetrain sound was louder then with the ls6. I would say it's ok.

Fast98Z28

Even with it feeling "rough" at higher RPM's(with 7.425's) than it did with the 7.4's (much smoother)?

With the 7.4's it felt pretty smooth compared to the 7.425's. But with the 7.4's after 2k miles it started "ticking" (in the video above) and after inspection of everything i put it back together and the "ticking" went away but still had the dreaded sewing machine noise.

So should i go back to the 7.4's or shorter? I will most likely re-measure length this weekend

Zmg00camaross

iTrader: (11)

Your correct on just measuring it. Double check the PR length. Install correct rods and set preload and run it. Sewing machine noise isn't bad but normal. Annoying it can be though. Hell my piston slap in cold weather sounds like it's about to fly apart haha. Normal ole crap

Fast98Z28

Sorry if this sounds like a noobie question, but if i dont ask ill never know. What do you mean by "set preload"? this is my first experience digging into a valvetrain and diagnosing issues. As far as i know, you check the length at TDC on piston #1, order new PR's and put them in using the correct torque sequence

Can you set preload with stock rockers?

And yes, piston slap is horrible! I remeber the first time i heard that noise...

Thanks for your help

03Sssnake

iTrader: (20)

You cannot adjust pre-load on/at the stock rockers, its only done by measuring and installing the correct pushrod, that will determine pre-load.
.

garygnu

did you use new lifters or reuse the originals lifters.how many miles on the rocker arms ?if alot consider some new comp trunnion bearings .

sgtrgpfdps

Ls1 are like that. I start my car cold no ticking, 30 seconds latter slight ticking starts warm up to ops temp no ticking. I have no idea whats going on. 2000 TA ws6 with only 8600 babied miles

96capricemgr

iTrader: (1)

With a stethescope you could have heard the injectors.

Fast98Z28

Well I installed 7.375 push rods tonight. I drove it down the road and the car runs really rough at low rpms till about 2k. to the point where the car was shaking. When i had installed the 7.425's it ran rougher in higher rpms.... with the original 7.4s that were in there it ran smooth, but that was when i started hearing the tick after 2k miles. I guess the 7.4's are the correct length and ill just have to deal with ticking every once in awhile. I will install those tomorrow.
I guess this was just me being paranoid about my new engine that i just spent a bunch on but im gonna install the 7.4's and drive it untill break in is done and let her rip!