Trying to understand how OHV works

Kinja'd!!! by "traderQAMobileTestAutomationMobileBoostOn" (el-peasant)
Published 01/14/2017 at 22:10

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6.1 Hemi Valvetrain here.

11 (Cam) rotates in block and nudges 16 (Roller), pushing up 19 (Pushrod)

19 pushe lifters on 2 (Rocker shaft), the other side of 2 pushes 4-10 (Valve)

18? Apparently it’s called an “aligning yoke.” No clue what it does

1, 3, 12-14, 17 are immobile parts


Replies (5)

Kinja'd!!! "DC3 LS, will be perpetually replacing cars until the end of time" (dc3ls-)
01/14/2017 at 22:16, STARS: 5

It keeps the lifters aligned perpendicular to the cam. So the roller doesn’t destroy itself by riding on it at an angle.  

Kinja'd!!! "traderQAMobileTestAutomationMobileBoostOn" (el-peasant)
01/14/2017 at 22:20, STARS: 0

Got it.

Kinja'd!!! "Urambo Tauro" (urambotauro)
01/14/2017 at 22:34, STARS: 2

That aligning yoke isn’t needed for older “flat tappet” setups. In fact, flat-bottomed tappets (no rollers) need to rotate in place, to help to keep a uniform finish where they contact the cam lobe.

Flat tappet setups are older, simpler, and cheaper, but as you can imagine, they experience more friction than rollers. My truck has flat tappets (and it’s a 1995 model!), and I have to add ZDDP to the oil at every oil change for better lubrication.

Kinja'd!!! "crowmolly" (crowmolly)
01/14/2017 at 22:48, STARS: 2

Also, flat tappet cam break-in can go wrong. Not good.

Kinja'd!!! "Rock Bottom" (rockbottom81)
01/15/2017 at 03:29, STARS: 1

Another way to keep the rollers aligned is to tie two adjacent lifters together.

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