Interesting rocker arm shaft

[Vetteman61]

   I had my '390 rebuilt.  It still smokes out one side, as I've mentioned previously.  Apparently, each rocker arm shaft is designed to go on a particular side, and if you try to use 2 rights or 2 lefts, it will not work properly.  If they are crossed, the engine book says they may spit oil on the valves and cause oil consumption.
  Has anyone heard of this or experienced it.  I don't think the vast amount of smoke I'm having would come from this situation.

   Thanks,
    Brandon

[Dan LeBlanc]

Keep in mind, it doesn't take a whole lot of oil to make a whole lot of smoke.  It may be worth the shot to swap them.  It's not that big of a job after all.  Should be easily doable within a couple of hours.

[Vetteman61]

The engine has had this arrangement since I've owned the car, which is about 9 years.  It started smoking on a trip in '08.  I didn't drive it again until this year, when I had the engine rebuilt.  After being rebuilt, it still smokes.  If the rocker arm shaft were the cause, I feel it would have smoked ever since I've had the car.

[Coupe]

I checked the shop manuals for my '57 and '62. The '57 has notches in the ends of the rocker shaft that are to be oriented towards the center of the engine. The '62 just says to have "the oil grooves in rocker shaft facing downward and oil holes in shaft toward center of engine". They are not necessarily left and right, end for the ending the shaft will change the orientation of the grooves and holes. According to my Hollander manual Cadiilac used the same rocker assmbly from '58 thru '65.

[Vetteman61]

So is it possible to change the position of the end of the shaft and change where the holes will be, and fix a potential problem?   I haven't worked on this part first hand, but the mechanic showed me a picture, so I'm not very familiar with it.  From the description, it sounds like, as you perhaps said, it's making sure you put it back correctly rather than it being the right part or the wrong part.

thank you for checking the book

  Brandon Garrett

[Roger Zimmermann]

It seems that I did a copy of the shop manual showing the indentation on the shaft. If the shaft is installed on the wrong way (half a turn), this will prevent the good lubrication of rocker arms but not let the engine smoke. By the way, is the smoke coming from oil or from water? You may have a crack in one head and water is entering the combustion chamber, crating smoke. A CO analyser on the radiator could let know if this is the case.

Roger

[Vetteman61]

Well, it turns out the position of the rocker shaft is what was causing the smoking.  There's a small notation on the bottom of a page in an engine book about 390s.  If the rocker arm shaft is not turned exactly right, it will allow oil to be sprayed on the valves and cause smoking.  The shaft was moved and it cured the problem.  What a hassel all of that way.

brandon