mopar valve adjustment

garyc · 07-12-2022, 11:13 AM

going from non-adjustable rockers to adjustable on my 400 stocker hydraulic cam, using hydraulic until new motor is ready, how do i adjust them? back in the days (small block chevy) ran engine backed off until they clicked then tighten one turn,
put a pushrod thru stamped steel rocker

CMcAllister · 07-12-2022, 11:53 AM

Been awhile, but on hydraulics, we always just went to zero lash. Preload beyond that made it possible for the lifters to "pump up" at high RPM and prevent the valve from fully closing.

Might be a hillbilly way to do it, but we would run the valve adjustment just like a mechanical cam, but would loosen the adjustment a touch until it had clearance, then spin the pushrod with fingers while slowly tightening the adjustment. When the pushrod got snug, stop. Done.

Like I said, been awhile.

65signet · 07-12-2022, 05:56 PM

Turn the adjuster until they are zero lash, and then add 1/2 to 3/4 turn.

Larry Hill · 07-13-2022, 07:53 AM

You could pull the lifters out with the heads on, shim the lifter to very limited or no travel reinstall and set as solids. That is if you have stock heads.

DanBar · 07-13-2022, 11:04 AM

First know how much preload works best for your application. Second divide the number of threads per inch of your adjuster into 1. that tells you how much preload per turn off adjuster. as an example if you have a 20 tpi adjuster that's .050" per turn. if you want .012" preload that would be 1/4 turn past zero lash. hope this helps. Dan

Mark Yacavone · 07-13-2022, 01:47 PM

First thing I would ask is what height solid are you using to check the cam lift with?

GTX JOHN · 07-15-2022, 02:41 AM

I would do Zero lash plus 1/4 for that set up.

e vassar · 07-15-2022, 10:42 PM

Years ago 440 with hyd cam in a bracket car. After making a lot of adjustments and a lot of runs, zero lash then 1/4 turn was best.

07-12-2022, 11:13 AM	#1
garyc Member Join Date: Mar 2021 Posts: 124 Likes: 0 Liked 51 Times in 30 Posts	mopar valve adjustment going from non-adjustable rockers to adjustable on my 400 stocker hydraulic cam, using hydraulic until new motor is ready, how do i adjust them? back in the days (small block chevy) ran engine backed off until they clicked then tighten one turn, put a pushrod thru stamped steel rocker

07-12-2022, 11:53 AM	#2
CMcAllister Senior Member Join Date: Sep 2006 Location: Fulton County, PA Posts: 603 Likes: 15 Liked 890 Times in 248 Posts	Re: mopar valve adjustment Been awhile, but on hydraulics, we always just went to zero lash. Preload beyond that made it possible for the lifters to "pump up" at high RPM and prevent the valve from fully closing. Might be a hillbilly way to do it, but we would run the valve adjustment just like a mechanical cam, but would loosen the adjustment a touch until it had clearance, then spin the pushrod with fingers while slowly tightening the adjustment. When the pushrod got snug, stop. Done. Like I said, been awhile.

07-12-2022, 05:56 PM	#3
65signet Member Join Date: May 2010 Location: El Dorado Ca. Posts: 121 Likes: 291 Liked 44 Times in 21 Posts	Re: mopar valve adjustment Turn the adjuster until they are zero lash, and then add 1/2 to 3/4 turn. __________________ Steven Barnes Stock 704 N/SA

07-13-2022, 07:53 AM	#4
Larry Hill Live Reporter Join Date: Oct 2004 Location: Hickory, Ky Posts: 10,614 Likes: 1,901 Liked 10,655 Times in 2,211 Posts	Re: mopar valve adjustment You could pull the lifters out with the heads on, shim the lifter to very limited or no travel reinstall and set as solids. That is if you have stock heads. __________________ IHM Used Parts https://ihmusedparts.com 888-821-1817

07-13-2022, 11:04 AM	#5
DanBar Junior Member Join Date: Jan 2022 Location: summer shade ,ky Posts: 15 Likes: 21 Liked 9 Times in 4 Posts	Re: mopar valve adjustment First know how much preload works best for your application. Second divide the number of threads per inch of your adjuster into 1. that tells you how much preload per turn off adjuster. as an example if you have a 20 tpi adjuster that's .050" per turn. if you want .012" preload that would be 1/4 turn past zero lash. hope this helps. Dan

07-13-2022, 01:47 PM	#6
Mark Yacavone Veteran Member Join Date: Mar 2002 Location: Miles From Nowhere Posts: 7,790 Likes: 2,882 Liked 5,080 Times in 1,936 Posts	Re: mopar valve adjustment First thing I would ask is what height solid are you using to check the cam lift with? __________________ "We are lucky we don't get as much Government as we pay for." Will Rogers

07-15-2022, 02:41 AM	#7
GTX JOHN VIP Member Join Date: Jun 2009 Location: Boulder City, Nevada 89005 Posts: 2,720 Likes: 2,770 Liked 2,436 Times in 688 Posts	Re: mopar valve adjustment I would do Zero lash plus 1/4 for that set up. __________________ John Irving 741 Stock 741 Super Stock

07-15-2022, 10:42 PM	#8
e vassar Member Join Date: Jul 2015 Posts: 378 Likes: 67 Liked 267 Times in 106 Posts	Re: mopar valve adjustment Years ago 440 with hyd cam in a bracket car. After making a lot of adjustments and a lot of runs, zero lash then 1/4 turn was best.