Underdogg

well everyone, after finally getting through all the hard ships and headaches of getting my build done. i finally got to enjoy my car again.... for a couple days.

i heard some light tapping noise coming home from helping the local wild horse mustang club at one of their shows, we vette clubs guys were guest judges sort of.

it started of rather light and barely noticable. then progressively got louder the farther i went...

got the car home and pulled the driver side valve cover off and found 2 of the yella terra intake rocker arms to be broken. and i mean in pieces broken. the point of failure was the bottom part that goes around the shaft joing the pair of rocker arms, the piece that is held next to the snap ring. i guess a good way to describe it is the bottom half of the circle of metal that goes around the end of the rocker shaft.

there is also a whole butt load of needle bearings in my head now. i only hope that none of them got into the lifter trays during all this...

anyways, i have been doing some searching and found there to be a fairly good amount of people both with ls1 and ls3 yella terras that have been having trouble.

i have a set of ls3 heads on top of my new lq9. everything is new including the roller rockers.

the only one that i have found to be broken are the middle 2 intake rockers that are off set. i havent checked any of the other ones or the ones on the other side.

i have things to do as i am going out of town all next week and i dont have time to be tearing my car down all over again.

my question is, has anyone recently had a problem out of yella terra rocker arms? when i first fired up my car after having finished installing everything i was so amazed at how quiet and smooth the yella terras were compared to my old HS roller rockers and was very pleased.

i could hardly tell there was even roller rockers installed. i was very impressed with them. i guess that is why i was so shocked to see what had happened. all the bolts were still tight and the correct trq was put on each rocker arm bolt prior to starting the motor and the valve cover spacers were installed no problem.

my only idea is to try and get in touch with a distributor as i dont really know if there is an office in the usa that i can call. id also like to have the whole entire set up replaced. it will have me very nervous to drive my car again knowing that if this was some sort of qa/qc failure that there would be a possibility of the others that look to be fine now failing later on down the road.

for reference the cam specs arent very big and the valve springs are not radical either.

any advice or ideas of why this happened would be nice.

Txsailor

To destroy rockers in this short time it would seem something is seriously wrong! Were your valve springs correct for the lift of your cam? It sounds like coil bind to me. I would guess that they are just slightly binding or you would have some bent pushrods as well. Have you checked that you have at least .050 less valve lift than the coil bind height of the spring? Don't forget to figure in for any increased rocker ratio you may have with the new combination. If a cam is advertised with .595 with a 1.7 ratio and you go to 1.8 you will have .630 which could be too much for then springs. Also make sure your retainers are not contacting the top of the valve guides (and seals).

I haven't messed with these LS engines much but have built lots of perfomance small & big block chevys and all engines are very similar when it comes to setting up the valvetrain.

RonSSNova

Give us some specifics on valve lift and spring pressure. Or just the springs used. Coil bind is a possibility.

I haven't started my engine yet, I hate to think what awaits me. I'm approx 440 over the nose but YT doesn't seem to advertise max pressure. .6" lift with AFR upgrade springs.

Ron

vettenuts

Make sure you thoroughly check your setup. Did you verify the wipe before installation? Coil bind as previously mentioned? Clearance to the rocker arm from the pushrod, spring retainer, etc.?

Here is some information on who to contact. I would e-mail Jim at YT in Australia directly.

Hi Guys,

Our LS rockers have been selling for many years globally and it is rare and a surprise that some sets have failed.

We stand by our products and if anyone breaks an arm within 12 months or 10,000 miles of purchase the set will be replaced with a new SET and the old ones will need to be sent back to our Meridian MS office for thorough inspection and analysis.

With any broken rocker set we will require:

Date of Purchase
Who you purchased from
Cam spec
Type of Spring Rates
Installed spring pressure and expected open spring pressures (if known)


For people who question our quality ...fyi ...ALL The YT LS1 LS2 LS3 and L67 and LS7 rockers are all designed and made in Australia under strict quality ISO 9001 QA control.

Our products use full compliment Torrington needle roller bearings, All our aircraft grade alloy comes from the USA from the same material/ same mills that many of the top shaft race rocker manufacturers source from.

We have over the past three years have sold 000's of YT6645s and this is a vary rare instance.

Ive already spoken to a few of you guys on other forums and feel free to contact either our VP USA Doug Smith ( doug.smith@makogrp.com)or email me directly (jim@yellaterra.com.au) on any issues with our products.

Once again thank you for supporting Yella Terra and using our products.



Jim Petrakis
Yella Terra Australia

Underdogg

i have emailed them about the failure. i havent heard back from them yet. i may try to contact jim at his email. the office in mississippi isnt really offering much help as of yet.

the springs are patriot gold duals. used on a butt load of set ups. spring pressure is 375 i believe. im not exactly sure. cam lift is 617 intake and 595 exhaust. springs are rated for .660 lift.

i spoke with doug smith and after informing him about the situation and the set up i have he said that nothing seems out of place on my end.

i emailed him the pics and he said he will forward them to the engineering office in australia. if they can determine that it was a flaw in the rocker then they wont hesitate to send me another set asap.

now how long that is going to take i have no idea. im trying to stay optimistic at this point but after 5 long months of knuckle busting hard work i just want to really drive and enjoy my car once again.

099blancoss

They had a bad batch a long time ago, how old are the rockers?

tblu92

Do you have the new "Ultralight series rockers ? The older ones were very heavy and they would harmonic at hi RPM's (above 6400) the newer ones are much lighter and work great- especially at hi RPM's
As other say YT's are the best --I agree that you may have some other things going on-
I would 1st suspect that your push rods are either too long or too short--2ndly you may be experiencing some coil bind--or the springs are going--could be a mis-alligned rocker shaft or pedastal

Underdogg

the push rods are correct. the springs hardly have any miles on them. maybe 3500-4000. how do i know if i have coil bind issues?

they were bought from hinson a couple of months ago and i assumed they were the ultra lights. i didnt know there were any others being sold for ls motors....

Txsailor

When setting up heads its pretty easy to check to see if the springs are going to bind. First installed height is checked with a height gauge. You use the locks, retainer and what ever shims and measure at what height the spring will be when installed. Then with the spring in a valve spring tester you see what height the coils stack up solid. I like to have at least .050 more installed height than the coil bind height of the spring.

With the heads installed on the motor you could slowly turn it through by hand and make sure you had clearance between the coils at full lift. You also need to make sure the retainer is not hitting the top of the valve stem seal.

VGLNTE1

The problem is not the rockers, its the valvetrain. Do you have the correct size for valve seats? This happen on a friends new ls3 after a cam. Snapped 3 rockers in half.

Underdogg

are the valve springs sizes different for different ls motors? is one spring kit different than another? i removed the entire patriot kit from my ls1 trickflow heads and had the entire kit installed on the ls3 heads. if the shop i had do the swap didnt replace the entire kit and this was the result then i will talk to them about getting me the new parts i need to get this situation handled. i would just like all the info before i start making accusations...

i turned the motor over before starting it so i know there was space between the coils.

RonSSNova

I bet if you ask here and on the LS1Tech site, someone will have a spare or two you can use.

Ron

vettenuts

Note that when you turn it over by hand you won't achieve full lift because there is no pressure in the lifters. It might be worth double checking the installed height so you can calculate the clearance to coil bind.

Underdogg

how do i check installed height?


i really appriciate all the replies guys. after putting all this time and money in im getting a little frustrated and about ready to just sell the car. its become more of a headache than an enjoyment at this point...

RonSSNova

Pushrods ok? I would think coil bind might also bend pushrods. Something else to check. Especially on the rockers that broke.

If you have a valve spring compresser you can check coil bind. Piston at BDC, compress the springs to your lift and check with a feeler gauge. Just make sure you push the valve tips down with the retainer.

Ron

vettenuts

You will have to sort it out, it can be frustrating but in the end you will understand the car a little better.

What tools are at your disposal? That's probably the first place to start. Ultimate would be spring compression tool for removal of valve springs and a spring height micrometer but there are other ways to do this if you don't have these tools.

Underdogg

i have a degree in automotive tech and i have plenty of tools and if i dont have the tool i need i can def get it. ive done the whole motor build and swap with my own tools in the driveway on jack stands.

i know the car pretty well by now lol

and for the record it ran smooth as silk when i did the break in and everything on the bottom end. no metal in the pan or oil other than the sheen that was expected.

the push rods are not bent, which is why i thought first about the rockers being bad. none of the springs are broke and none of the bolts had come loose. i mean it was driving like a brand new car untill this happened...

vettenuts

That doesn't sound like a coil bind issue then. Have you examined all the rockers, even those not broken? Look for cracks where the others broke. Since you have the tools, do you have any dye penetrant to check the other rockers for the start of cracking?

Underdogg

I have the equipment to do pt testing and mt testing. It's what I do as a profession now. I'll have to ask my boss to see if I can use the pt stuff we have at the office. Mt won't work very well

Underdogg

Just got off the phone with Doug and he is sending me an email with information on where to send my old set of arms. After that he'll be getting a brand new set out to me ASAP.

I am happy and great full that things turned out ok and I will be getting my car back on the road again soon. Doug was great and was very nice about the whole situation. Very good customer service. I provided the information that was asked of me and things went well.

Can't wait to get home and get the rockers off so they can be mailed and my new set can. E on the way!!