Pushrod length w/roller rocker

-
M

megavites

Well-Known Member
Joined
Mar 17, 2017
Messages
106
Reaction score
17
Location
Jackson, NJ
Measured up pushrod length with Comp cams checker. I have a .043 variance due to valvestem heights (stock variance is .030).
My plan is to go longer pushrods(all 16)…so that all lifters will get some pre-load on assembly (.006 to .050).
That will leave me with adding in .040 to .075 preload with the adjusters (Comp cam 1622 rollers) due to these
lifters needing btwn .080-.095. Comp tells me 1 full turn is .050-.060…the threads are 20TPI which comes out to .050.
so that keeps me 1 to 1 ½ turns approx.

This is all based on readily avail. pushrod length. I realize I could go custom length using longest measurement and dial less in w/adjusters.

Am I on course here?
 
megavites said:
Measured up pushrod length with Comp cams checker. I have a .043 variance due to valvestem heights (stock variance is .030).
My plan is to go longer pushrods(all 16)…so that all lifters will get some pre-load on assembly (.006 to .050).
That will leave me with adding in .040 to .075 preload with the adjusters (Comp cam 1622 rollers) due to these
lifters needing btwn .080-.095. Comp tells me 1 full turn is .050-.060…the threads are 20TPI which comes out to .050.
so that keeps me 1 to 1 ½ turns approx.

This is all based on readily avail. pushrod length. I realize I could go custom length using longest measurement and dial less in w/adjusters.

Am I on course here?
Click to expand...

Sounds right, but you know that ideally all the valves are at the same installed height.
 
When you determined the pushrod length, where was the adjuster screw located within the rocker arm? IIRC they recommend 1-2 threads showing at the pushrod end of the adjusting screw.
 
69_340_GTS said:
When you determined the pushrod length, where was the adjuster screw located within the rocker arm? IIRC they recommend 1-2 threads showing at the pushrod end of the adjusting screw.
Click to expand...
measured with the adjuster all the way up....so one adjuster would be about 1 turn and the rest between 1 to 1 1/2 turns.
So I'm right about where your saying...1-2 threads showing on bottom side.
 
Just make sure that pushrod cups will clear the underside of the rockers on the pushrod side through the valve lift cycle. The adjuster balls not being down far enough may allow the edge of the cup towards the shaft to contact the underside of the rocker, which would really mess things up. This is gonna occur near/at max lift, so you need to look at that. The fact that you had no adjuster threads showing on the underside the rocker when you measured made this problem more likely. Is there a slightly shorter pushrod availble?
 
These rockers use ball/ball pushrods. The "cup" is in the protruding part of the adjusting screw. You can't really screw the screw in far enough to cause anything to interfere.
 
You must log in or register to reply here.
-

Back
Top