predatorz28

Just finished my SNS Stage 2 milder cam install a couple nights ago and everything seemed great. Valvetrain was quiet and everything seemed good. Today I took it on it's 3rd drive since the swap and it developed a loud ticking noise. To me it sounds like lifter tick. It is relatively quiet at idle but when driving it gets very loud. I replaced the oil pump during the swap, and oil pressure is good with 40 psi at idle. I used the dowel rod method to keep the lifters up during the swap.

Right now I'm thinking one of my lifters are done, or pushrods are possibly too short. I ordered the 7.400's with the cam package and I measured and came up with a 7.325 at zero lash, meaning my preload should be .075. I found the pushrod length checker to be a little tricky to use so I also counted the number of turns from zero lash to 22 ft/lb and it was just short of 1 3/4 turns. This gives me an approximate preload of around .080.

I'm leaving for vacation tomorrow so I won't be able to tear into the car until a week from now, I just need to get some ideas on what I need to be checking when I get back. Has anybody every experienced something like this? Also, I would be interested to see what pushrod length other people are running on the SNS stage 2. I'm thinking I might need the 7.425's. Heads/gaskets are stock.

predatorz28

Forgot to mention that the car is not tuned yet and I'm on stock lifters with 124k on the clock

sreve

iTrader: (3)

I installed that same cam this spring 2000mi on it
it's quiet I used 7.4 pushrods and preload was about
1-5\8 turns LS7 lifters.
Looking under the valve cover and barring the motor
over is where I would start.

predatorz28

Yea I figure the first thing I need to do is pull the valve covers and re-check my preload on each lifter.

high impact

iTrader: (5)

Preload sounds good on the one(s) you originally checked. You will have to check preload on every lifter and you may find a collapsed lifter. Although if it only only rattles at higher rpm you be chasing a ghost. 124k on those lifters is a ton of miles, what kind of lobes does that cam have? Are they aggressive?

predatorz28

I only checked on the two lifters for cylinder #1 during the swap, I'll be checking all of them now. It ticks at every rpm, with it being more noticable with increasing rpm. I'm not sure exactly what kind of lobes they are, but it is the milder version of the cam. Specs are 226/234 .605/.612 on a 110 lsa. Maybe Martin can chime in with more specifics on how aggressive the lobes are. Pulling the heads scares me but changing to ls7 lifters might be necessary and give me good peace of mind with the miles the engine has.

predatorz28

Alright guys I finally got around to taking the valve covers off and everything checked out good except for a clogged pushrod. I unclogged the pushrod and the noise still persists. This noise comes only when holding above 1500+ rpm for at least 30 seconds. Once I let the engine idle the noise goes away after another 30 seconds.

Does sound like a bad oil pump o ring to anybody? I replaced the oil pump during the swap and re-used to o ring since the pump didn't come with one. At cold start up I have 60 psi at idle and when it gets warm I have anywhere from 30-40 psi.

Streetlegal?

iTrader: (25)

Does the tick increase with rpm increase? Pull out your pushrods and check them to see if they are straight. I had the same thing and it turns out I slightly bent about 4 of my hardened pushrods. Visually they looked ok but they had just enough bend in them that they had metal to metal rubbing marks.

predatorz28

Yes the ticking increases with rpm. I would think a bent pushrod would tick all of the time, not intermittently. Was yours consistent?

Streetlegal?

iTrader: (25)

Yes mine was consistent. It just sounds a lot like what mine did. When you pulled the pushrods out did they have any marks on the sides of them?

You said all the rockers were torqued to the correct spec or else I would say check that.

Maybe if you took a video of it it would help more. Could you try that?

sick_tight

in for an answer, ive got the EXACT same problem. LS2 forged and stroked to a 402, oil is about 60 at start up and 30-40 after warming up. It really isnt prevalent until higher up in the RPM range (above 1500 like you) ive got a video clip with the sound maybe its similar to yours? and mine does follow RPM.

http://www.youtube.com/watch?v=bo_QP...ature=youtu.be

mayve if it is just like yours this will help people trouble shoot?

Streetlegal?

iTrader: (25)

That kind of sounds like what mine was doing except mine was happening more frequently. Granted I bent 4 pushrods. sick_tight have you pulled the valve covers and checked the pushrods? It takes all of 20 min and it'd be better to find out that it's that instead of the lifters then you don't have to pull the heads. Were your heads milled at all?

This is what my bent ones looked like. They were visually straight but when you rolled them you could tell they were bent by the way they sounded in comparison to the non marked up ones. They were hardened pushrods too so you can still bend them just seems like not as severe.

predatorz28

From what I can tell, yours sounds more "rattlely" than mine. Mine sounds more like a solid tick/knock that starts out quiet then builds up to be very loud. It only occurs when holding the rpms above 1500 for more than around 30 seconds when at operating temp, then it goes away when I let it idle for a bit. If I just rev it up like you were in the video, it sounds completely normal.

sick_tight

alright, ill pull the covers and look at the pushrods, my heads are milled but im not sure how much. it was all done by a reputable shop out in houston by a previous owner but you never know. Ill take a look, thanks. sorry predator i thought we might have been ticking "buddies" haha

Streetlegal?

iTrader: (25)

The way you describe your noise it sounds a lot like what mine was except it would not go away and it was at all rpms. I'd take a look at the pushrods and hope it's just that since that is an easy fix.

If your heads are milled and you are using the stock length pushrods they are going to be too long. It's quite easy to check the pushrods so do that. Make sure the surface is perfectly flat. They visually might be straight but listen to the noise it makes when it rolls. If it makes somewhat of a pulsing sound vs a consistent sound they are bent.

sick_tight

yeah im not sure what length pushrods I have but doesnt hurt to check, any way i can easily tell if i have a broke valve spring? or is that one OBVIOUS. never dug into the trouble shooting side of valvetrain

Streetlegal?

iTrader: (25)

It's quite obvious if you broke a valve spring when you take the valve cover off. Not sure what kind you have but usually you can move them around if you broke one. If you have duals maybe you only broke the inner one (if you did in fact break one)

As far as the pushrods, if you milled the heads you need to get the proper length pushrods.

sick_tight

sounds good, but no i didnt mill it it was milled with the build from what i know

Streetlegal?

iTrader: (25)

If it was milled before hand and you are using stock length push rods then they are too long. You need to get an adjustable push rod tool to measure the length you need. There's a couple threads on it somewhere around here.

predatorz28

Alright, the ticking is definitely coming from the drivers side. I just re-checked the top end on that side and everything is fine. I'm pretty certain one of my lifters just said "hell no" to the new cam.