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340 spacers/shims for stock rocker arms side play

Started by Cudakiller70, May 26, 2017, 10:16:22 AM

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Cudakiller70

340 with new stock rockers and shafts. There seems to be a lot of side to side play/slop. Depending on rocker arm location pushrods look like it could rub on head more importantly the rocker tip doesn't look to be centered on valve stem depending where it ends up. They can't move enough to come off valve stem, but not ideal if it goes to one side. Would like to shim a little here and there to insure rocker tip stays closer to center of valve stem.
What are do you think? It'll be OK? Just run it?

Shane Kelley

Quote from: Cudakiller70 on May 26, 2017, 10:16:22 AM
340 with new stock rockers and shafts. There seems to be a lot of side to side play/slop. Depending on rocker arm location pushrods look like it could rub on head more importantly the rocker tip doesn't look to be centered on valve stem depending where it ends up. They can't move enough to come off valve stem, but not ideal if it goes to one side. Would like to shim a little here and there to insure rocker tip stays closer to center of valve stem.
What are do you think? It'll be OK? Just run it?
It would be fine. That's how they came from the factory. But myself I would probably shim them. It's time consuming to get them just right. Great piece of mind though. I don't run the stamped, I like the adjustable ones from the old 273's. That way you know valve lash is perfect. Sometimes cut heads or block deck height can effect valve lash.

Cudakiller70

Thinking of 273 rockers, missed a decent deal a while back. Have gone back and forth stamped vs roller. Looking at shims like these
http://www.manciniracing.com/hash0wispsmb.html


Shane Kelley

Quote from: Cudakiller70 on May 26, 2017, 10:35:09 AM
Thinking of 273 rockers, missed a decent deal a while back. Have gone back and forth stamped vs roller. Looking at shims like these
http://www.manciniracing.com/hash0wispsmb.html
You probably only need the thin ones stacked to get the width you need. I think those big ones will be the wide. The last big block I built I used a couple sets of thin ones to get them correct. They came from 440 source. You check Summit?

Chryco Psycho

Any that has usd PRW rockers probably has a pile of extra shims available

jimynick

I noticed this on my 360 when my son pulled the valve cover and we traced it to the fact that the rocket scientist who'd removed the rockers the last time had screwed up the holdown placement. The rocker shaft holdowns are different widths and he put a skinny one where a fatter one should've been with the attendant sloppiness and mis-alignment to the valve stem. Check that first!
In the immortal words of Jimmy Scott- "pace yourself!"

Cudakiller70

Quote from: Shane Kelley on May 26, 2017, 10:51:42 AM
You probably only need the thin ones stacked to get the width you need. I think those big ones will be the wide. The last big block I built I used a couple sets of thin ones to get them correct. They came from 440 source. You check Summit?
Checked summit and jegs ended up getting some from McMaster Carr
https://www.mcmaster.com/#catalog/123/3281/=17tuprl

Quote from: jimynick on May 26, 2017, 05:19:04 PM
I noticed this on my 360 when my son pulled the valve cover and we traced it to the fact that the rocket scientist who'd removed the rockers the last time had screwed up the holdown placement. The rocker shaft holdowns are different widths and he put a skinny one where a fatter one should've been with the attendant sloppiness and mis-alignment to the valve stem. Check that first!
Thanks for the tip, just checked it, all is good.