Another broken Yella Terra rocker arm
05-19-2013, 12:14 PM
#22
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400 lbs open spring pressure, according to info on trickflows site.
I'm gonna find out if they will replace the whole set with the revised ones.
Keep in mind when I said Another broken Yella Terra rocker arm, this is the first one I had break. It cant be from improper setup as much as I've driven the car with these.
I'm gonna find out if they will replace the whole set with the revised ones.
Keep in mind when I said Another broken Yella Terra rocker arm, this is the first one I had break. It cant be from improper setup as much as I've driven the car with these.
My first set lasted about 5-7k miles, second set less than 10. My 3rd set is still sitting in the box, waiting on my 403 to be finished.
05-19-2013, 01:15 PM
#24
Brian Tooley,
Have you ever heard of Comp Cam's Ultra-Gold™ ARC Series Aluminum Rocker Arms ever failing? I've seen them installed in mags and Steven Rupps' LS454 with TFS235s.
Would you have luck with Cranes' new aluminum rockers yet?
thanks,
Jim
Have you ever heard of Comp Cam's Ultra-Gold™ ARC Series Aluminum Rocker Arms ever failing? I've seen them installed in mags and Steven Rupps' LS454 with TFS235s.
Would you have luck with Cranes' new aluminum rockers yet?
thanks,
Jim
05-19-2013, 07:44 PM
#26
But for how long?? How long can an aluminum rocker take the pressures?
05-19-2013, 09:29 PM
#28
05-19-2013, 09:32 PM
#29
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Like your post states, you have the newest rockers that haven't had a failure reported ATM. These were still the old style rocker. I'd run them without another thought. I will be
05-20-2013, 02:49 AM
#31
So they've had three revisions? I thought they just had two. My apologies for messing that up.
My fear would be they've revised it once already and it still was prone to failure and required a second revision. Did they finally get it right? Or is it that there hasn't been enough time for the aluminum to fatigue and fail again?
My fear would be they've revised it once already and it still was prone to failure and required a second revision. Did they finally get it right? Or is it that there hasn't been enough time for the aluminum to fatigue and fail again?
05-20-2013, 05:48 AM
#32
I thought I saw a broken "new revision" YT here a few months back?
I know Scorpion has a bad name from all the 2009 ****, but since THEIR last revision, I haven't seen a reported failure. They're more the no questions asked guys. And they're American made... Just a thought.
Only reason I haven't went with ANY of them is weight. Everyone tells me to steer clear of them and stay with upgraded stockers.
I know Scorpion has a bad name from all the 2009 ****, but since THEIR last revision, I haven't seen a reported failure. They're more the no questions asked guys. And they're American made... Just a thought.
Only reason I haven't went with ANY of them is weight. Everyone tells me to steer clear of them and stay with upgraded stockers.
05-20-2013, 06:37 AM
#33
So they've had three revisions? I thought they just had two. My apologies for messing that up.
My fear would be they've revised it once already and it still was prone to failure and required a second revision. Did they finally get it right? Or is it that there hasn't been enough time for the aluminum to fatigue and fail again?
My fear would be they've revised it once already and it still was prone to failure and required a second revision. Did they finally get it right? Or is it that there hasn't been enough time for the aluminum to fatigue and fail again?
05-20-2013, 09:27 AM
#34
So, what you're saying is that daily driven miles are harder than race miles? Had that motor been raced more, I bet it would have broken alot sooner than 22,000 miles. The only thing why DD miles would be any harder is the heat cycle, hot then cold alot more often. Fact: Race miles are much harder, and will cause parts premateur wear.
OP, that sucks! but atleast it did not do any serious engine damage! Good luck!
05-21-2013, 04:15 AM
#35
One other thing I found was when I swapping in stiffer pushrods the upper end of the RPM curve was much more stable and actually increased 6 rwhp. This tells me the 5/16" pushrods were flexing under the higher spring forces and this will provide some inconsistent loading into the rockers. My findings have been verified by several engine builders with one even stating that a stock LS6 benefits from stiffer pushrods.
There might be several factors involved with some of these failures. I think initial setup is just as important as the lift and spring rates.
05-25-2013, 10:12 AM
#36
I contacted Scoggin Dickey on Monday, sent them pics & they flied a warranty claim with Yella Terra. After waiting all week & not hearing anything I ended up ordering a pair of rockers yesterday so I could drive the car for the weekend, new set is stamped on the right so appears these are the revised ones. $54 + $25 overnight fee. I'm gonna cross my fingers that I don't break another one.
05-26-2013, 06:53 AM
#39
One thing I have wondered and never gotten an answer on was whether the latest design is a drop in for the old, i.e., are the lifter cup/roller/fulcrum geometric relationship the same? I don't want to have to re-shim and then order new pushrods especially since I have custom double taper pushrods.