Welcome to moparts

Moparts Tech Archive

Motor General

Valve Adjusting Chart (90 degree method)

Another method that's popular plus instructions that apply to hydraulic lifters, thans to TJP.

Remove the valvecover
1. Loosen all the adjusters one turn.
2. Place the valvecover back on the head.
3.Start the motor and let it run for a couple of minutes to pump the lifters up completely. Shut the motor off
4. Remove the valve cover and disconnect the coil wire
5. On each cylinder
Adjust the intake as the exhaust valve starts to open
Adjust the exhaust as the intake is almost closed.
While tightening the adjuster roll the pushrod between your fingertips. When you start to feel resistance that is zero lash.
Continue to tighten the adjuster 1/2 to 1 turn (this amount is debateable depending on who you listen to) I ususally use 3/4 of a turn which would equal approximately.030 lifter preload. Most manufacturers reccommend .020 to .040 preload. Most adjusters are 3/8 - 24 thread. 24 threads per inch = .042 per revolution.
On the valve seq thing. it's real easy to remember if you do it like this.

You ALWAYS start by adjusting valves 2 & 8 at TDC And the intake is Always the first # expressed, 2 intake, 8 exhaust. like that.

So write down;
2 & 8 on a piece of paper, then under each of them right the rest of the firing order down.

2 & 8 @ TDC
1 & 4 turn 90*
8 & 3
4 & 6
3 & 5
6 & 7
5 & 2
7 & 1

If you don't have the chart under your hood or have access to the chart it's easy to make your own.


Back to Tech Index
Tech Index