0331MARINE

Well that took awhile to read. Great info and nice to see a company take care of the problem. I'm just now starting to get everything for my head swap. Still stuck between the YT's or just doing to Comp trunion upgrade.

Mike94ZLT1

How long have you had them, and how many miles were on them?

Z06ufgrad2002

Do you have any pics you can post of the damage?

I need to go back and check when mine were installed.

ZZ06

Wow that sounds very familiar to what happened to mine. This was on my CamaroSS when I owned it though. It happend 4 years ago now. I knew they were YT's but i wasnt the one who bought them or had them installed. I bought the car like it was. 224/224 .581 .581 112lsa with chromoly pushrods and comps 918 springs. I had the car 2 years before that event happend. One day i heard the good ole "sewing machine" sound that seemed abnormal then before. And throughout the day it progressivly got worse. Everyone on LS1tech who was tryin to help suggested pullin the valve cover and havin a look see. Sure enough on the passenger side, One of the YT had broke right where the pushrod contacts. I never tracked the car either. Sorry for the story and hijacking just sharin my experience with YT. I didnt ever bother to call it in bc i had no clue when they were purchased or how long they had been in the car before i got a hold of it. So i had to suck it up and replace it.

zeevette

I've had my HS full rollers for about 6k miles now, and I just removed the covers, and removed all the rockers/PRs to inspect. Everything looked normal. The HS rollers are kind of klunky looking, but seem to be durable enough. Knock wood.

vettenuts

Never heard of the bolts failing.

royalmike

I now its been a while since last post, but as its very related just fault I would post this that I have just posted on The C6 tech forum.
Are those that had them replaced still running them any problems as not shore to buy another set or something different.


Driving my 2007 LS2 vette 23,000 miles quite gently when all of a sudden start hearing loud banging noises from engine so dip the clutch and pull over get a tow back home.

Now engine has a few mods Lingenfelter: Cold Air Intake, GT11 cam 215/231 .631/.644 118.0 C5R timing chain. LPE Large valve ported heads. 2.055" / 1.57". Yella roller rockers. Manta pushrods. Ported throttlebody and Fast 92mm intake. TB Spacer. 47 lbs. injectors. Kooks 1 3/4 headers with High Flow converters. Lingenfelter: Cold Air Intake, GT11 cam 215/231 .631/.644 118.0 C5R timing chain. LPE Large valve ported heads. 2.055" / 1.57". Yella roller rockers. Manta pushrods. Ported throttlebody and Fast 92mm intake. TB Spacer. 47 lbs injectors. Kooks 1 3/4 headers with High Flow converters.

I was just about to change the dual valve springs which I had just received along with spring compressor and airline fitting to keep valves up and fault this may have been problem as existing had close to 12,000 miles on them.
So removed valve covers and find one rocker snapped in two push rod looks ok on first inspection and can’t see any other stress marks on the other rockers. After a bit of a search round the internet looks like there have been a few failures of these rockers and he manufactures have recently upgraded them.
Link http://ls1tech.com/forums/generation...failure-5.html
So questions
• Is there likley to be any damage to cylinder heads vales from a snapped rocker?
• Best replacement for my car or use these updated Yella rockers.
• I have new double springs and compressor tool to stop valve dropping is it much of a job to change the rockers at the same time, and DIY wright ups.

sabastian458

I plan on continuing use of the YT's. this will be my 3rd set, 2nd updated set. A friend of mine is on his 2nd set, which looks like my 3rd set.

I will say from what I have found is that aggressive lobes combined with high spring pressures will cause these failures. I have paid very close attention to my current build to make sure I don't go out side YT's specifications. I don't want another failure.

Most likely no internal failure or damage relating to the failed rocker. I will say that there might be valve/piston damages if you had any valve float. No way to tell if so without pulling heads or using a bore scope to take a peak. I'd run as is tho. New push rod on the rocker that failed, don't reuse that one.

sabastian458

Oh wanted to mention that I can not get any cylinder head porter to work my TFS 220's over. I believe it's due to having to use these rockers. But why that matters to them I don't know. I can not get anyone to give me a price for porting at all. So I am considering changing heads and rockers only due to not being able to port them.

royalmike

Thanks for the info
Thinking I may just change all rockers and springs now as with summer here want it back on the road asap about a 1,000 if I do it, do you think I will need new valve cover gaskets they look fine?

vettenuts

Curious about your current valve springs and their installed height/seat value. You have a lot of lift so the open spring loads may be quite high.

sabastian458

I don't think I have ever replaced a set of valve cover gaskets on these engines, even the 100k miles ones. If you keep the YT's they need under 410lbs spring pressure

royalmike

Just under
Part # O.D. I.D. Seat Load Open Load Coil Bind Rate (Lbs./In.)
937 1.300 .895 135 @ 1.770 400 @ 1.120 1.040 408
Thanks for the info
So lock-tight on the threads of the rocker retainers is it 23 lbs torque do I need sealant on the end bolts do they enter water.
I have taken the rest off the rockers of now and no sign of any stress cracks etc on theses. Read some-ware that the newer ones were beefed up a bit in critical stress areas.

sabastian458

What heads are you running? My TFS heads I HAVE to run sealant on the bolts for the intake valves, runs right into the runner. I never ran anything on the exhaust, never had one loose torque either. I always recheck at 50 & 100 miles afterwards.

vettenuts

These must be tightened in pairs so each cylinder needs to be brought to TDC on firing stroke. You can seal the bolts with Loctite 242. Use stock 22 lb-ft torque for bolts. If you haven't checked, you should ensure the wipe is correct. This can also lead to issues and also increased guide wear. If you need to shim, than you also must re-measure for pushrods. See this post: Link

bmfvette

I have the new version of YT's. They are beefed up on the arms. There was a thread on here (or maybe LS1Tech) that showed the early/later versions side by side. Just looking at the picture you could see the difference. Since I haven't seen the early version (in person) I couldn't tell you where else they are beefed up. But the backsides look beefy as well. I'm also running TF/TEA 215 heads and added the sealant only on the intake as they do protrude through the runner. You will more than likely have to use the shims to get the wipe pattern correct and 1.5 turns after zero lash. As vettnuts say's measure your pushrods accordingly.

I only have minimal miles on this setup do to travel (build was early winter) so I have my fingers crossed on the new YT's. I saw all the post before I decided to go with them (and wouldn't have if they didn't revise them).

Also, did you ask TEA to port your TF's? They do all the CNC work for TF. In fact they are neighbors. If not talk to Mike.

RonSSNova

I have the early style, with the beefier AFR springs. I'm right at 600 thousandths lift. Set the wipe pattern via shims etc etc.

I have 60-65 dragstrip passes on mine, so I guess I've tested them well.......but no guarantee they aren't going to break.

Ron

Mike94ZLT1

I'm sure glad I got those out of my car when I did!

sabastian458

I. Have emailed TEA a few times without response. I received 1 quote from late model race craft, $1,800 to port them. That more than the heads originally cost me, $600 more and I can get new CNC heads.

sbadd99

running YT light weights with patriot springs and putting out 463rwhp never had any issues, but anything can fail