Forced_Induction

Took the car out today to go to work like I do everyday, as I came to a stop sign on my street the top end of the motor began to knock and the car tried to stall. I shut it off immediately. The first valve cover(drivers side) I opened I saw the broken YT rocker.





What do you think it is? A collapsed lifter?



Engine Mods:

TSP LS2 402 Forged Stroker ~11.4:1 Compression
Wiseco -10cc Pistons .010" Over
Wiseco Steel Top/Napier 2nd Ring Set
Callies 6.125" LS1 CompStar Rods
Callies Stroker CompStar Crank
ARP Main and Rod Bolts
TFS 235cc CNC Ported Heads Milled to 61cc Chambers
Dual Valve Springs and Titanium Retainers
Yella Terra UltraLite Rockers 1.7:1
7.5" Chromoly Pushrods
LS7 Lifters
VRX Cam 247/251 Duration .624/.624 Lift on 112+4 LSA
ARP Cam Bolt
ARP Head Bolts
Cometic Multi Layer Steel Head Gasket .040"

blackz97

Check out this thread.

https://ls1tech.com/forums/generatio...t-rockers.html

WKMCD

iTrader: (2)

I've broken 2 from 2 different sets. I just pulled them out and put in CHE's from Richard at WCCH- proheads.com

Make sure you can COMPLETELY reconstruct the rocker from the pieces to make sure none went anywhere. The first breakage I had to pull the head to get all the pieces.

Forced_Induction

Was the last you broke the very last revision of them? I think they have three different designs to try to cure the problem.

WKMCD

iTrader: (2)

I've broken the first and second iteration. I'm done with them. Richard has not had a single failure with the CHE's after selling hundreds of sets.

miami993c297

iTrader: (6)

Hi Kevin,

You are not going to believe it.....YT Ultralite 3rd generation in my engine!!!!

Running by their specs, by their valve springs, still some Morel's racing with the required preload, the very stiff pushrods from Manton.

the engine is definitively idling better, a lot more quiet in any circumstances, and is cruising even better than before when the GM OEM rockers (with trunion upgrade) were in the engine...
Did I mention NO valve float or valve-train instability of any sort revving daily my big valves to 7250rpm!!!

I am satisfy with the new behavior of my engine with those last generation Yella Terra ultralite...let's see how long that will go.

Christian

Slowhawk

iTrader: (12)

I've seen the older versions break like that. Not many but a few. I run the newest model ones on my personal car. Held up fine so far with pretty heavy springs to handle 7400rpm and 20lbs of boost with no issues.

Mark200

What dual springs?

WKMCD

iTrader: (2)

Hey Christian,

Glad they're working for you. I've lost faith in them so I'm going to something more bullet proof and the CHE's.

Kevin

JakeFusion

iTrader: (7)

Fun times.

I almost pulled the trigger on the latest generation YTs... but decided to take my chances with the Lunati Trunion kit. I'll see how it works out. Using PAC-1904 dual springs 150/400#.

BriancWS6

iTrader: (18)

How can it be verified if a guy has the newest versions? I already knew about the offset stamping. I built a 347 for a guy about 2.5 yrs ago, using Yella Terras and he has had zero issues. Couple more builds coming up using them too, just curious on this.

botlrokit93

iTrader: (1)

Im a total newb here, but while researching these rockers for my LS3 heads, I was told to look to the Ultralight series to get the latest iteration of these rockers. I ordered mine from Hinson for 485 bucks, and was pleased to see that they now include ALL hardware neccessary for installation including valve cover spacers. (not sure if these are absolutely needed.) As for the OP, the one pic looks like there is a small gouge in the valve cover rail right at the pushrod end of the broken rocker... did it make contact? the reason I ask is that I noticed my rockers are WAY close to contacting this area even though my LS3 heads have clearance notches for the rockers in this area. Just throwin an idea out there..

BriancWS6

iTrader: (18)

All three sets I am talking about are indeed the ultra lights. I know that the newer version has the rocker ratio stamped off set. But it was the statement "3rd generation" of these rockers, that peaked my curiosity.

Was it 1st generation stamped center, then second generation beefed up and still stamped center, then third generation stamped offset? Or was the second generation stamped offset and the third generations have a more subtle change, while still being stamped offset? That's what I'd like to get to the bottom of.