Old School M/T method for PR length
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Old School M/T method for PR length

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    gn7
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    Default Old School M/T method for PR length

    knew I had this some where and dug it up. Wonder if Mickey would think this was valid today. This is the method he used for his small block Harvey Alumn entry in '63. Funny as hell if you read it. I am all about keeping the valves at the same heigth, but not real big on sinking them just get my PR's to work, or grinding the stems for the same reason. And the rocker geometery is a little wack. Bottom line, it's not the PR length that needs changing, it's all in the valve height. What to do when the valve gets +.100 or +.250 longer Sorry tried to make it larger but it would upload. The 3 rocker views are not the rocker going thru its arc but the starting point for the rocker for different lifts. He recommends the second arrangement and that is what the tool duplicates.



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    Last edited by gn7; 10-17-2008 at 05:22 PM.

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    I can't read the article but... My auto shop teacher in high school (late 70's/early 80's) said something along the lines of changing the valve stem height to adjust where the rocker arm "rides" on the valve stem... probably pretty old "techonology" (term used loosley).

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    Quote Originally Posted by gn7 View Post
    knew I had this some where and dug it up. Wonder if Mickey would think this was valid today. This is the method he used for his small block Harvey Alumn entry in '63. Funny as hell if you read it. I am all about keeping the valves at the same heigth, but not real big on sinking them just get my PR's to work, or grinding the stems for the same reason. And the rocker geometery is a little wack. Bottom line, it's not the PR length that needs changing, it's all in the valve height. What to do when the valve gets +.100 or +.250 longer Sorry tried to make it larger but it would upload. The 3 rocker views are not the rocker going thru its arc but the starting point for the rocker for different lifts. He recommends the second arrangement and that is what the tool duplicates.
    GN-7, I will throw this out and do with as you will. Light spring an intake and exhaust. Take a 5/16 pushrod and cut it close to the top, Tap the internal with a 1/4 tap and get some threaded rod. Screw into push rod and adjust to the lenght that works for the proper geometry. Then go order the right push-rod length. I may be a old schooler but it is how I have done it. It will save material in the valve pocket and be cheaper in the long run. IMLAO. Mark

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    Quote Originally Posted by hotrod56cars View Post
    I can't read the article but... My auto shop teacher in high school (late 70's/early 80's) said something along the lines of changing the valve stem height to adjust where the rocker arm "rides" on the valve stem... probably pretty old "techonology" (term used loosley).
    Lots of the new import stuff does it this way.
    Quote Originally Posted by gn7 View Post
    It would be a balmy 85* in Steel's shop if he would move a little faster

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    Quote Originally Posted by ol guy View Post
    GN-7, I will throw this out and do with as you will. Light spring an intake and exhaust. Take a 5/16 pushrod and cut it close to the top, Tap the internal with a 1/4 tap and get some threaded rod. Screw into push rod and adjust to the lenght that works for the proper geometry. Then go order the right push-rod length. I may be a old schooler but it is how I have done it. It will save material in the valve pocket and be cheaper in the long run. IMLAO. Mark
    Thank you for the lowdown. Would have been a little more helpful if you would have said what "the proper geometry" is though. Please understand that I didn't start this thread as recommendation on how to set rocker geometry, but more how NOT TO. This was meant to show how screwed up they were back in the 60's on this subject. Nobody in their right mind would cut a seat or grind a stem to get "proper" geometry today, anymore than they would use the same method to set their lash.



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    Quote Originally Posted by gn7 View Post
    Thank you for the lowdown. Would have been a little more helpful if you would have said what "the proper geometry" is though. Please understand that I didn't start this thread as recommendation on how to set rocker geometry, but more how NOT TO. This was meant to show how screwed up they were back in the 60's on this subject. Nobody in their right mind would cut a seat or grind a stem to get "proper" geometry today, anymore than they would use the same method to set their lash.
    Swing and a miss. I tried to give you a way to get P/R length and also watch how the P/R mates to the rocker and lifter in a perpindicular fashion but I geuss it went over your'e head. And what happened in the 40-50-60s is why we are where we are today. By the way I have said this in other threads, Ol Guy was a nickname created by my kids and I use it. My racing and building started in the mid 70s when I had a machine shop/ auto parts store with my father. That being said, there were cyclinder heads that required the valve tip being raised or lowered to set valve lash either by tip grinding or seat adjustment. Check it before calling B/S.

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