I've got an 89 Formula 350, it's got 125K on the original stock engine and still runs smoothe as glass. No knocks, no weird noises. I've also got an 88 Camaro Sport Coupe that had an LO3. Now it has a crate Vortec 350 with a ZZ4 cam. The heads and springs were upgraded/modified in order to handle the lift of the cam. Otherwise the engine is stock. It's got about 2K miles on it now but that engine makes a lot of noise. Especially the rockers. They're extremely noisy. I hear a lot of ticking from under the valve rockers. I would expect more noise from roller rockers but not from stock stamped steel rockers. I would expect it to sound like the L98 in my Formula. Smoothe without the excessive ticking. Do any of you guys know what this noise could be attributed to? Or is it supposed to be noisy due to the cam upgrade?

Thanks,

Gene

 

What lifters did you use?

 

They're the stock roller lifters.

 

you said you used new springs to handle the cam's lift. what springs did you put on, and with what heads?

 

The heads are the stock vortecs. And I have no idea what springs are on there. I purchased the engine already built. But the engine has been suspect from the beginning. It bent a pushrod within the first 10 miles of driving it. My mechanic had to pull the valve covers and he found the rocker arms were coming loose. So he pulled all the rockers, put loc-tite on the studs and re-installed the rockers. It's always made the ticking noise from the beginning but last March I got the Formula 350 and noticed the difference in how the engines sound.

Gene

 

Retainers are hitting the valve guides....

It's a wonder you haven't broken any push rods or pulled out any of those pull-out studs. If you had some REAL rockers on there, that didn't flex and flop around in the breeze like stock sheet-metal ones do, you'd have already found the next weakest thing in your valve train.

Vortec heads are WIDELY known to have an ABSOLUTE MAX of about .480" valve opening before the retainers come into contact with the guides.

 

I took that statement at face value, sounds like you really don't know.

Also, what exactly is a "crate Vortec 350"? Is that the 330 horse crate engine, or a replacement L31 engine? The 330 horse engine has flat tappets, while the L31 has roller. You said it has stock roller lifters, that would only be the case for the L31 engine.

 

The studs are the screw in studs. And as far as the heads, I was told by the guy that built the engine that the heads were modified to accept the lift of the cam. It's quite possible that they weren't and it's also quite possible that it wasn't "upgraded" with the ZZ4 cam either. Thanks for the replies and I'm going to have it checked. If I didn't have another engine in the works as we speak I would just swap to some aftermarket heads. Thanks again for your time.

Gene
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It's the L31 replacement engine.

Gene

 

I talked to a local guy who owns a shop(sells aftermarket stuff like intakes, cams, cylinderheads, etc...). He also has several machine shops that build engines for him and he sells them in his store. He also mentioned about the retainers hitting the guides, the rockers coming loose or the rockers need to be re-adjusted. He also said that if it's made the noise from the beginning it's more likely the retainers hitting the guides. I'm pretty sure the rockers aren't coming loose because I watched my mechanic put loc-tite on every rocker stud and torque them down. But I won't know for sure until the valve covers are pulled. So I'm going to pull the heads and have them properly modified or I might just replace them altogether. They're 062 casting vortecs and I've read on here to stay away from that casting.

Thanks,

Gene

 

There's nothing wrong with the 062 casting.

The magazine that started that rumor even retracted it the next month.

You can pop a couple of retainers off yourself, take a look at em, and tell if that's the problem.... that's what I'd do, since it seems pretty likely to me. No point in waiting for somebody else to do it for you.

See my sig for a brief hint on the logic of troubleshooting.

 

What will the retainers look like if that's the case?

Thanks for your time,

Gene

 

In the center on the bottom, there'll be a witness mark where they've been hitting the guide. There'll be a corresponding mark on top of the guide.

Won't be hard to spot, if that's what's been going on.

You might see smashed bits of seals littered around the area too.

 

Thanks. I'll get to it as soon as I can. Hopefully tomorrow evening.

Gene

 

The exhaust has more lift on a ZZ4 cam, so those would be good ones to check first.

 

Thanks. Just so that I understand it correctly. If the retainers are hitting the guides, that means the cam has to much lift for the springs so they're being compressed so low that the retainer at the top of the spring is hitting the valve guide on the cylinder head. Plus the valve guides weren't machined(i.e. they stick out to far)for the higher lift cam. Am I correct? I know a few things about engines but I've never really messed with the valvetrain. I let the machine shops worry about it. If I had purchased from someone who knew what they were doing I wouldn't be worrying about it right now. But that's alright. It's a learning experience. Thanks again for your replies and your time. Hopefully I can get to it this evening after work.

Gene

 

Right; the guide is a big lump of casting that the valve slides through, and in the Vortec heads, it's HUGE. Which is why the valve can't open very far before the retainer reaches it.

The guides are also HUGE in OD, as well as their height. Regular decent valve springs won't go onto them because the damper inside the spring won't fit. So, get them cut down to some normal-ish size; with the right cutter, it's a one-step operation anyway so it might get done regardless, but definitely ask and make sure.

They're TERRIBLE about their valve train, in stock form. Really a shame that they made these great heads with all this tremendous intake flow but then messed up all the other details so bad.

 

I removed the driver's side valve cover this evening and everything looks okay under there. A few of the rockers had a small amount of play side to side but still very tight. And it turns out I've got 906 castings as opposed to 062 castings. I'll loosen a couple of rockers tomorrow evening and pop a couple of retainers off.

Gene

 

The 906 are the ones that are supposedly "Bad". It's all a bunch of baloney. I got am otor with 906's about go in mine.