Good evening,
2005 Pontiac GTO with LS2 6.0 and a 6-speed manual transmission. Mods for the install are as follows (relative mods):

Heads:
Trick Flow 225cc (Unmilled/ Untouched)
Stock Head Gaskets

Intake:
Fast 102
Stock LS2 Throttle Body

Cam and Valvetrain:
Polluter LS2 V2 (239/244 .635/.610" LSA = 111 + 2
LS7 Lifters with ~.050" preload
Trick Flow Valves
Brian Tooley Valve Springs with Steel Retainers (max .660" lift)
Yella Terra 1.7 Solid Roller Rocker Arms



Exhaust:
Kooks 1-7/8" Headers
Kooks Off-Road Mid Pipes
Stock 05 GTO Resonator
Pipes the rest of the way

I've done a heads and cam build before with my old WS6, however that was a small cam (TSP 224R cam). This will be my first big cam build. Anyway, the symptom is that the engine is ungodly loud. It's louder than the exhaust. The best way that I know how to describe it is that it sounds like a stock car with open headers. Except, the noise is coming from the engine. Something's definitely not right...

My first impression was that this might just be the Yella Terra's hitting the valve covers. I took both valve covers off and there are no marks on them. It should also be noted that I did install the Yella Terra spacers and did not torque the valve cover bolts down too tight (per their instructions). I did also install the small nuts that came inside of the pack which also gives more space from the rocker arm to the valve cover.

I'm honestly lost at this point. My old WS6 had lifter tick before I did the install and this is definitely not lifter tick. Is this just the way that a huge cam sounds before it is tuned? I would be more than glad to answer any questions about the way that I installed this setup.

Thank you for reading the long post.

 

Did you measure for proper pushrod length after everything was installed?

 

Did you check piston to valve clearance along the way?

I know the cam is SUPPOSED to work....but even Tick recommends measuring before operating.....

KW

 

This is what I'm thinking the problem is. Yes, I measured and got a measurement of 7.500. However, I'm thinking this is off because of how loud the valvetrain noise is.

The way that I measured was by taking a permanent marker and rubbing it all over the top of the valve stem. I then placed the bolts in for the Yella Terras and took an extension with the hex socket and threaded the bolts in by hand without a gear wrench. This is what Yella Terra claims will put the lifter at zero lash. I then rotated the engine over several times and then removed the bolts from the Yella Terras. Here are my results:

 

So did you hand tighten the rocker bolts until you could not turn them anymore or did you tighten them only until all of the slack was removed between the rocker tip and the valve?

Rocker wipe pattern looks fine by the way.

 

.050 pre load is not enough for LS7 lifters...you need to be in the .080-.100 range. That is the wrong lifter for that application anyway...imo if you wanted to use drop-ins then a Johnson 2110 should of been used or at bare minimum the Morel 5315.

 

I did not use aftermarket lifters because I feel that the Quality Control (QC) is not as great as the OEM standard. I read many threads about all of the failures all the way through-out even the high dollar 700 buck lifters. I couldn't justify paying that much money and feeling unsure of how the lifters would do in my valvetrain. Per GM spec, the recommended lifter preload on the LS7 lifters is .050" - .070".

While I do disagree with your lifter preload spec, I do agree that the amount of preload on these lifters has to be incorrect, hence the loud valvetrain noise. After reviewing the ls1howto.com guide on the Yella Terra rocker arms, the recommend turns on the bolts after zero lash is 1/4 turn to 1/2 turn and no more than 1 full turn. On my setup, I performed a 1/8 turn before reaching 25 ft*lb's torque.


140K GXP, I first got both the intake and exhaust valve springs to the fully compressed position. Next, I took a hex bolt with an extension and hand threaded both of the bolts on the Yella Terras using two fingers. When playing with the pushrod using my pinky, I was unable to move the pushrod around. I also checked to see if there was play in the rocker arm (there wasn't). After this, I took a wrench with the extension and torqued it down to 25 ft*lb's. The approximate sweep after zero lash was an 1/8 turn. I'll try a shim and see how this helps.

I will not be able to do this until Saturday though, I'm currently on a business trip. I'm also purchasing a magnetic base dial indicator this week to make absolutely sure how much preload I've got on these lifters.