I recently replaced all the valve stem seals on my stock 78 403 engine, they all came out in pieces. When taking the rocker arms off the nuts were torqued to at least 50lbs and were hard to break loose. I torqued them back to 25lbs and thought that was correct but EVERYTHING I see on the internet says to adjust them like a Chevy engine with pre-loading the lifters. What is the correct way to set up the rocker arms on a small block Olds with stock hydraulic lifters and the saddles between two rocker arms?
P.S. 3 of the saddles were broken.

 

There is no adjustment at all they are just bolted down you can put spacers under the bridges to reduce preload or play around with pushrods. Bolts hold everything down not nuts unless someone put something there that isnt stock.

 

Yes, I miss-spoke, they are bolts. Thanks.

 

#1. It takes more torque to break loose something thats torqued to a specific amount. In other words, it takes more than 25 ft/pounds to break bolts loose that were torqued to 25 ft/lbs. Torque wrenches are calibrated (unless they are the "beam type" torque wrench) to be accurate in the normal right hand (clockwise) torqueing. You could have had some "Loc-Tite" on the threads.

#2. If you torqued them to what the CSM specified, that was correct. The Oldsmobile CSM is correct. Without reading what "adjusting them like a Chevy engine", I will make comments on what I can document.

A. Available from the GM History Center is a "Super Tuning the W machines" manual that appeared around 1968-1970. It did cover shimming the rocker arm stands to reduce pre-load for racing. They cautioned against having shim thickness difference of .030" or more on bolts of the same rocker arm stand.

B. A personal observation of mine is this. Those cheap "hair pin clips" that pop in the internal groove in four places in the lifter body to retain the lifter plunger is a weak point. Replace those with internal snap rings that fit the groove. This important fact was mentioned in an article in FX/Super Stock magazine around 1969-1970. This was about an NHRA legal stock W-31 about Rich Powers who was an engine Engineer at Oldsmobile at the time.

C. Rich Powers described his valve lash procedure to some extent in the article. The closer to zero ash you come the more critical the internal snap rings become. If you run solid lifters, internal snap rings are a must.

 

We broke 3 bridges when we pulled rocker arms off my 403 with hand tools, years back. As said, seemed tighter than 25 ft-lbs but probably wasn't. An impact actually loosened without breaking. The steel replacements don't break as easy but can twist, had that happen. It is a good reliable setup IF everything is in tolerance including acceptable wear on parts.