kidreno_21

http://www.youtube.com/watch?v=pv5IyWXL8dc

So, what do you think? Bad lifter?

I have been breaking YT 1.7 rockers, three so far. I heard this new noise, pulled the valve cover, no broken rockers. I've been in contact with Tony at AFR. He got me in contact with YT's American source.

I am getting frustrated. Running 7.4 push rods. Guess I am going to have to measure for pushrod length.

Pics of broken rockers: http://www.facebook.com/album.php?ai...4&l=b733bd4eef

kidreno_21

Come on, 16 views and no one will even comment? Am I posting in the wrong forum? It is an LS3 block, IV Gen. And I am quite sure it is internal.

Ban1dit

iTrader: (1)

It could be a lifter. Sounds pretty eratic to be one though. When my lifter went bad it was a constant tick. The best thing to do is pull the heads and check. That way you can eliminate the guessing.

kidreno_21

Thanks for the reply, but I already pulled the valve cover and the rockers are fine. The noise, when driving, is only audible when throttle is applied. But, when the hood is up and engine is running, well, it is as you see in the vid.

Are you all able to view the pics on my Face Book page? FB says the album is public, so you should be able to view it.

Thanks again.

hirdlej

iTrader: (31)

Sounds like a header leak to me....... If you're not already doing so, use GM exhaust manifold gaskets. What do your fuel trims look like?

bigboykilroy

iTrader: (48)

why are you running 7.4 push rods with 60 cc heads and that cam?
What lifters are you using?
What is your lifter preload?
If you have snapped rocker arms already you got issues.
You definately need to use a length checker and measure your setup.

kidreno_21

I thought it might be an eshaust leak, too. I tightened them down, both sides, ticking is still present.

The use of the 7.4 push rods was also my question to my builder. He told me that the amout of material removed from the head is insignificant to rod length. Obviously, he was wong. On a side note, the heads were milled previously to me purchasing them. I bought them from LGM, who, at the time, installed my head/cam package, and the heads were milled to a 59cc chamber. LGM also installed the push rods, leading me to believe the 7.4 would, in fact, be suitable for the remilled heads.

I am using LS3/LS7 lifters. I do not know what the lifter preload is.

Yella Terra is being very helpful with the broken rockers. I have been in contact with thier VP of Sales and Marketing, and he is going to replace the entire set of rocker arms I currently have.

Thanks for your responses guys.
Brent

mred

iTrader: (5)

could a pushrod be hitting the guide plate? or the rocker arm out of adjustment "GEOMETRY"
thanks
Ed

kidreno_21

Well, I feel like an idiot. I trailered my Camaro up to LG last week and they dove in. The ticking was an exhaust leak. Passenger side header was loose. And the reason the rocker arms were breaking? Well, can't say we're 100% on this, but they think the springs were too strong for them. They changed the rockers from the YT 1.7 to stock LS1 rockers. And you know what? This car has never run more smooth, almost feels like it is stock again.

Thanks for your input guys.