COMP Cams® Quick Tech: Achieving Proper Rocker Arm Geometry

[seapeddler]

Ford pedestal rockers best. Although the rocker bolt is only 5/16" dia., the fulcrum hole is ovoid, which allows fore& aft movement for precise geometry. Keep in mind that lifters should be fully pumped up and the final adjustment should allow slight drag of rocker on stem tip. So, when the valve face seats in the seat the valve moves upward some. Even then, you may have to re-shim to get the highest vacuum reading which should be 22 in. stock cam. Volks system has no roller tip. Same idea.

[joebirdable]

maaaaaaaan this some bullshit...................if we paid attention in geometry/algebra 8 we wouldnt be busting our nuckles puttin our own shit together we'd just go to summit racing equipment and pick up some turn key 572 crate motors,then have our man servants install them and call us when its ready! this just made me wanna buy a fkn crate motor!!!!

[seapeddler]

Because of the nature of stud and valvestem centerlines, does using a longer pushrod actually cure the problem? Comp cams should design a roller rocker that has an eccentric (stud hole) stable pedestal that can be moved fore and aft to equalize the stem / stud centerlines. All to often a machine shop does a great seat / guide job, but the valve stems don't line-up axially, nor are they the same height. Why shim and buckets deleted from most V-8's is cost.

[Eightbanger]

I don't mind letting everyone know how math illiterate I'am...because it was all good until we got to 1.17 and a whole bunch of hieroglyphics came up on screen, then some foreign language about 50 thou, I mean what size is 50 thou? is it found on a tape measure? I wouldn't know 50 thou if I fell over it on the street.

It's frustrating because I bought these checkers and they are great, I followed all this tutorial and I'am close to the big reveal, when....WTF!

I hate being this dumb!

[hoghogwild]

@Eightbanger 50 thou, is 50 thousandths of an inch or 0.050" or 1.27mm.A human hair is approx 0.003"-0.004" depending on hair colour and race

1/2"=0.500" or 500 thou(500thousandths of an inch)

1/4"=0.250"

1/8"=0.125"

1/16"=0.0625"

1/32=0.03125"

The 50 thou(0.050") they are talking about is the distance covered by each turn of the checker is 0.050"( 50 thou) You dont have to actually know how to measure this length with a micrometer/vernier because the lengthchecker does this for you.

[Eightbanger]

@hoghogwild Shame on me....haha

This is a great help mate, and will be to many others as mathematically challenged as myself. ;))

Thank You.

[greenjeens]

nevermind I found it.

[greenjeens]

whats the part number for that pushrod length checker? and can you tell me what marking compound you are using?