Fastt Gunn

Hey all....

Had heads & cam put on my '99 Z28 last night by my local F-Body performance shop. They have not done a set of HS rockers before, but have done many others.

I have the 1.7 non-adjustable's. I though they'd be a nice upgrade from stock. They were not able to see any clearance/ interference issues. The preload was perfect. They went right on no problem.

However, they are noisy noisy noisy....

So noisy in fact, that they put back my stock ones. After the swap, all was quiet again. He said the only noise after the swap was the sound coming out of the exhaust, not the motor . They didnt want me to pick up my car tonight and say "Why'd you break my car?"

Theyre stumped... I paid a few hundred bucks for them and now I'm not sure what to do

The stock one's have almost 80,000 on them. I was afraid with the higher RPM the motor will see, that I may drop needle bearings. I was gonna do a set of new stock replacemants but when researching before purchase, the guys who put on HS's didnt mention any excessive noise and beyond MAYBE having to grind the outermost rockers, they seemed like the ticket.

My guy even offered to put only the center rockers back on this morning to see if it was a clearance issue with the outermost ones. But wouldnt they have seen the clearance issue while bumping the motor over with the valve covers off? They said there was none. And I don't think there should be an issue with valve cover interference with '99 and up style valve covers.

Comments? Thoughts?

Thanks,
Glenn

NO CATZZ

iTrader: (10)

I use Harland Sharps with Comp R lifters. Took me a few trys to get the preload set correctly. They were a little noisy until I got the preload figured out. My heads are cut .030 and I run shorter pushrods and I ended up using a shim to get it all set. Another thing I did was completely clean the rockers with mineral spirits then soaked them in a coffee can full of oil. That way they are not 'dry' during the initial startup.

Any full roller rocker is going to be more noisy that the stockers but it should sound like a quiet sewing machine when it is all set right. Bigger cams cause the valvetrain to be more noisy also.

Fastt Gunn

Probably should have mentioned.....

The heads were only cut the minimum... .010 I think. I'm using a stock length pushrod, which was recommended for my setup.

The shop said the preload set up as expected.... I can't think of the exact procedure at the moment... you know... the "tighten to 22 ft lbs with less than x turns"...

Nasty N8

iTrader: (33)

From zero lash (rocker just dragging on the pushrod) it should be between 3/4 and 1 1/2 turns til you get 22LBS. Every setup is slightly different and should be checked to be sure.

Thanks Nate

PREDATOR-Z

What kind of heads? were they 5.3's.?

If so the Harlands hit the corners on certain 5.3 castings (Not all). To cure it need to grind the corners on the inside by the back of the rockers.

jd13

iTrader: (3)

I went with the 1.8s on a stock cam, and must say they are quite a bit noisier as well. I'm gonna check the preload again in the next couple days.

Krab

iTrader: (28)

That's weird, after installing my HS rockers (1.7 ratio), I had less valvetrain noise than with my stockers. I do have stock heads though...

Fastt Gunn

Yes, 5.3 heads from TEA....

There were no clearance issues. Rockers did not hit the heads at all. Preload was set correctly to 22ft lbs.

I spoke to TEA and they said they've been direct bolt on replacements when they've used them. No grinding necessary. And they havent been excessively noisy.

I've already decided to just sell them and put on a set on new stock replacements. For Sale: HS 1.7 Rockers :-(

I got to listen to my car in person last night and the valve train is quieter now with the new heads and cam then with the stock stuff. It sounded really good. I think I must have had a lifter or 2 that were bad, causing some tick.

Thanks guys....

White_Hawk

iTrader: (3)

Don't the HS rockers require new pushrods? I thought their add in Hotrod this month actually says that. It sounds to me like you need some that are a little longer.

-Geoff

Fastt Gunn

I did get new stock length chromoly pushrods. This is what was recommended by both Futral and TEA. The heads are not milled enough to warrant a different length.

If the length was an issue, I doubt the shop would have been able to set up the preload correctly, which they were.

pdd

iTrader: (3)

i didnt notice