There are 2 kinds of YT rockers
07-14-2013, 07:44 PM
#1
There are 2 kinds of YT rockers Those that have busted, and those that are going to bust.
I've stated in other posts that I've just been waiting!
I put the car in open loop and went for a 1/2 houre cruise collecting data. Made my tweaks, headed out for another cruise, got 1/2 mile from home....and OMG. Miss, knocking, backfiring. I thought I stuck a rod out the block. And I was just cruising, never even above 2k rpm.
But, the backfiring in the intake manifold was a clue. I figured if an exh rocker broke, no where for the exh gasses to go intil the intake valve opened.
I was right.
I bought these new from a forum member. I determined they weren't made during the dark period. I determined wrong.
I have a couple of spare pairs from someone elses set that suffered failures, so I will be back on the road.
Perhaps time for some Scorpions?
BTW, AFR Heads with the stronger spring option. Lift is .600 and this is an EPS/Pat G. grind with endurance ramps, not the fast stuff. Right at 405 open pressure.
The car is back alive and running well, time to resume my tuning.
Ron
I've stated in other posts that I've just been waiting!
I put the car in open loop and went for a 1/2 houre cruise collecting data. Made my tweaks, headed out for another cruise, got 1/2 mile from home....and OMG. Miss, knocking, backfiring. I thought I stuck a rod out the block. And I was just cruising, never even above 2k rpm.
But, the backfiring in the intake manifold was a clue. I figured if an exh rocker broke, no where for the exh gasses to go intil the intake valve opened.
I was right.
I bought these new from a forum member. I determined they weren't made during the dark period. I determined wrong.
I have a couple of spare pairs from someone elses set that suffered failures, so I will be back on the road.
Perhaps time for some Scorpions?
BTW, AFR Heads with the stronger spring option. Lift is .600 and this is an EPS/Pat G. grind with endurance ramps, not the fast stuff. Right at 405 open pressure.
The car is back alive and running well, time to resume my tuning.
Ron
Last edited by RonSSNova; 07-14-2013 at 08:48 PM.
07-14-2013, 09:41 PM
#3
4-5K miles.
I bought from a forum member, new in the box, I don't know when they were made.
Nothing wrong with the cup itself, but either the rocker machining for the cup was wrong, or the cup was slightly oversize. It appears to have has a stress crack in that area for quite some time.
I noted an intermittant ticking on that side, and even had that rocker cover off last week to look see.
Ron
I bought from a forum member, new in the box, I don't know when they were made.
Nothing wrong with the cup itself, but either the rocker machining for the cup was wrong, or the cup was slightly oversize. It appears to have has a stress crack in that area for quite some time.
I noted an intermittant ticking on that side, and even had that rocker cover off last week to look see.
Ron
07-15-2013, 05:30 PM
#5
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I have the same one on my LS2, been there for nearly 5 years, 25K+.
I'm starting to worry now.
By the position of the ratio stamping they are the early ones like mine, pre 2009.
From memory the ones that had lots of breakages around 2009-2011 had the ratio stamp on the left when looking from the outside of engine.
When I bought mine I contacted YT Aus and they told me there was a running change around 2009 and there was a problem with the extrusions but as mine were earlier version they should be fine but since then have seen a few break form all 3 versions.
I'm starting to worry now.
By the position of the ratio stamping they are the early ones like mine, pre 2009.
From memory the ones that had lots of breakages around 2009-2011 had the ratio stamp on the left when looking from the outside of engine.
When I bought mine I contacted YT Aus and they told me there was a running change around 2009 and there was a problem with the extrusions but as mine were earlier version they should be fine but since then have seen a few break form all 3 versions.
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07-17-2013, 01:36 PM
#8
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Those in the picture below are the "old" versions...
And now in the picture below the version before June 2010 and the UPDATED stronger version post July 2010...no breakage reported yet on those one since...
Christian
And now in the picture below the version before June 2010 and the UPDATED stronger version post July 2010...no breakage reported yet on those one since...
Christian
07-17-2013, 04:08 PM
#10
mass alone doesn't necessarily tell you about balance, or moment of inertia for that matter. it's the distribution of mass about the point of rotation that counts. without a CAD model it'd be very difficult to determine.
that being said, if someone weighs a rocker pair of the old version, i can weigh the new version for comparison......willing to take it apart to determine "moving masses", try to determine tip weights, whatever. there's numbers floating around on the old design out there but nothing on the new.
really wish we had spintron data on these as well.
edit: came across this, some good reading in here even if there are no answers: https://ls1tech.com/forums/generatio...rm-weight.html
that being said, if someone weighs a rocker pair of the old version, i can weigh the new version for comparison......willing to take it apart to determine "moving masses", try to determine tip weights, whatever. there's numbers floating around on the old design out there but nothing on the new.
really wish we had spintron data on these as well.
edit: came across this, some good reading in here even if there are no answers: https://ls1tech.com/forums/generatio...rm-weight.html
Last edited by ckpitt55; 07-17-2013 at 04:21 PM.
07-17-2013, 08:22 PM
#12
Yes. Hinson said they had only got them 2 weeks ago. And assured me they were the latest design. I guess I have some to compare to eh? 
Stumbled onto a sale as well, $439 shipped.
got the last set.
What's a mother to do?
And thanks guys.
Ron
Stumbled onto a sale as well, $439 shipped.
got the last set.
What's a mother to do?
And thanks guys.
Ron
Last edited by RonSSNova; 07-17-2013 at 08:27 PM.
07-18-2013, 07:54 PM
#15
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I'm in the same boat as Ron then lol I bought mine off a forum member. Does anyone have any spare old style rockers laying around? Don't have the money for a new set right now and have to get to work somehow.
