nitried or cryo
 

I'am having rocker arm problems. Which has shone results?? Ideas??
Thanks Larry

Re: nitried or cryo
 

Rocker problems on what?

Re: nitried or cryo
 

I used to break rocker arms on my FoMoCo 429 stocker every five or six runs, always an intake (2.25" monster). Had a brand new set of NOS rockers and fulcums cyro'ed three years ago, haven't broken one since. Might also be due to increased spring pressure/shubecks/smith pushrods, but it's worth a shot. Your mileage might vary.

Re: nitried or cryo
 

Chevy 427

Thanks Bill

Re: nitried or cryo
 

Larry, give Jim Bailey a call. www. finishedracing.com He will point you in the right direction.

Re: nitried or cryo
 

Crane Nitro Carb rockers cryo'ed.

They have worked very well for me. It's a good idea to run them for 3-400 runs and recycle them. Much like all valve train pieces, they need to be replaced after x amount of runs.

Andy Stone B/S 1102 SS/C 1112

Re: nitried or cryo
 

Larry, call Wes McCracken, John Musial, Charlie Weber, Charlie Downing, Chuck Beach, Bob Marshall, Brian Seibenick and see what they have to say. OR save some time and just give me a call. Keep in mind, nitried is a surface treatment. Cryo treats the entire part. Also, not all Cryogenic Processing is created equal. 330-858-1842. JB.

Re: nitried or cryo
 

Larry,
We run the stuff from Clark Holroyd, and have since 2006. We bought a complete setup, and have not broken a single rocker since. We are going to finally break down and put a new set of rockers on this Winter. I'm running 265# on the seat, and 550# open pressure. We turn as much as 7800 RPM, and make probably 100-150 passes a year, plus dyno time. Clark's stuff is just plain GM.

Are you fully deburring your rockers?

Where are they breaking?

Re: nitried or cryo
 

Alan, I've done several sets of Clark's Rockers. They are by far the nicest "stock" rockers that I've seen. Now, send me just one of your rockers. I'll treat it and provide you with a sample to try. It's on the house, what da you have to lose .JB

Re: nitried or cryo
 

Jim,

Wouldn't the ultimate solution be to deburr (especially the oil hole), cryo, then shot peen to impart compressive stress? Deburring removes stress risers and small tears. Cryo will stress relieve and improve grain structure. Shot peening will leave the entire outside surface in compression. Nothing fails in compression.

Am I thinking correctly?

Thanks

Re: nitried or cryo
 

Kevin: your right. With the problems we're seeing with stock rockers, you probably CAN'T go overboard in preparation. Anything you do (within reason) will help. The beauty of Cryogenic Processing and Rem Finishing is, it's easily done. It's inexpensive. And it works. Cryo'ing treats the whole part, inside out. It's a one time deal. The Rem Finishing leaves surface smooth, removes any surface imperfections, stress relieves it, yet retains enough microscopic peaks and valleys to hold lubrication. This leads to less friction, therefore less heat. Your Cryogenic Processed / Rem Finished Rockers will look like they're chrome plated. You can also do the rocker balls. It would be impossible to totally polish the rocker/and balls as well by hand, besides, who'd want to. I'm plugging the process here. I've seen the results when done correctly. JB.

Re: nitried or cryo
 

Jim,

I guess you would want to shot peen after cryo but before polishing then. Otherwise you would lose some of the benefits of the polished finish. Thanks. I'll be in touch.

Kevin

Re: nitried or cryo
 

Alan: I have everthing that clark makes. I think Kevin and Jim are close to the problem. I have never had any rocker arm problem before going to the 427. Now I have destroyed 2 motors this year.due to rocker arms and Schubeck lifters.
Thanks for every ones help.
Larry 2206 A/SA
PS Jim you got mail

Re: nitried or cryo
 

Larry,
I am Kevin's engine builder. The only thing we've ever broken was a stud, and that was before we bought the stuff from Clark. We've never had anything but a 427. If you want, send me a PM or an email with some pics. I can probably help you.