factory rocker limitations question

[chris401]

What are the limits of the factory adjustable rocker arms and shafts with no end support?  I guess I'm asking for max spring pressure and rpm that they would be able to handle.

I have broken a few shafts on the truck with .600 lift and less at what ever rpm it would do. At that time the shafts were 15+ years old. Recently tore down and refinished 17 1/2 sets and found 5 more broke shafts. I think it had more to do with how they had been R and R'd over the years. When you remove and install you line up the XX on your balancer marked about 20° ATDC. That takes all the lifters off full lift. Run the shaft bolts or nuts down evenly and follow the advice in the other post. Should be fine.

[pclowes]

Thanks everyone for the valuable feedback.

Has anyone tried the inexpensive rocker systems I see on ebay?  I've seen them in both aluminum and stainless steel, advertised under two names, Procomp Electronics or Speedmaster.  The aluminum setup goes for $159-227 and the stainless goes for $253-361.  ( I see used stock setups for around that on ebay.) 

Both are complete setups with end supports and seem to look good in the pictures.  Just wondering if anyone has tried them.

Thanks for that.


Just to add to the experience on these, my dad gave me a set of the steel Speedmasters. 

Nothing has broke on them, however...  after a few weeks I developed an oil consumption issue on the order of 1qt every 100 miles.  Thinking I had broke a ring or rings (the bottom end has a lot of miles on it) I started getting into the engine.  When I pulled the valve covers I had found that 3 of the 4 shaft end plugs had fallen out.  I had thought it was my bad for not checking that they were tight, but then when I put them back in I found out the threads in the shafts are cut wrong for those 3 and the plugs will just screw into the shaft indefinitely.   Turns out the oil consumption was from the tops of the heads being in an oil bath.  Since replacing the plugs with ones with a shoulder that will tighten the oil consumption has gone away. 

I am currently still running the setup while I build my new engine, but needless to say I won't be using Speedmaster again.