Valve adjustment
05-29-2018, 09:54 PM
#1
Melting Slicks
Thread Starter
Valve adjustment
I changed out some head gaskets now I must set the lash on the valves I watched a few video's and once you have taken the slack out of the push rods some go 1/4 round 1/2 one even goes a full round. Which method is right?
05-29-2018, 10:14 PM
#2
Race Director
All 3. Go 1/4 turn.
05-29-2018, 11:26 PM
#3
Melting Slicks
Thread Starter
1/4 is what I remember. My engine is still in a partially disassemble state. My rockers have a roller on them and I noticed a cam button on my sprocket. Would this still make it 1/4?
05-29-2018, 11:56 PM
#4
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You just BARELY take the up and down slack out of them. You want the cup in the lifter to be at the top with no preload. THEN turn the additional amount. The 1/4 turn was always the plan for something you wanted to try and RPM pretty high. But you have to be careful if the lifters just have little wire clips in them as they can come out if they get pushed against too hard by plunger during a valve float instance or something. Some higher end Morel lifters seem to like almost a full turn to keep them quiet. For normal street stuff that isn't going to be flogged too hard I'd use 1/2-3/4 turn to keep them quiet.
JIM
JIM
05-30-2018, 01:41 PM
#6
Race Director
05-30-2018, 08:59 PM
#7
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05-31-2018, 02:31 PM
#11
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St. Jude Donor '22
one thing for sure,
over tightening ain't good.
read too many "my engine don't run"
threads from too tight valves.
takes a good technique to set hydro lifters
when engine is not running.
constant feeling of pushrod while slowly tightening rocker nut
until you can't spin the p rod.
can't is relative in that a non pumped up lifter can collapse.
so, do your best to get the lifters full of oil, take small turns on the nuts,
take care to "feel" when slack is out of p rod and then turn
the amount you want to use as the final setting.
over tightening ain't good.
read too many "my engine don't run"
threads from too tight valves.
takes a good technique to set hydro lifters
when engine is not running.
constant feeling of pushrod while slowly tightening rocker nut
until you can't spin the p rod.
can't is relative in that a non pumped up lifter can collapse.
so, do your best to get the lifters full of oil, take small turns on the nuts,
take care to "feel" when slack is out of p rod and then turn
the amount you want to use as the final setting.
05-31-2018, 05:45 PM
#12
Race Director
Food for thought:
If we are dealing with a street engine that is not going to be driven like it was stolen and high RPM's all the time.
Back in the day. I was told by the old timers that setting the valve adjustment at one full turn will make it so when wear begins on the rocker arms and lifters. This will make it so the rocker arms will not need to be readjusted as quickly if they were adjusted at 1/2 of a turn.
Kinda made sense when I thought about it. But I do not get all hung up over this adjustment unless it is on an engine that is super high performance.
On an engine with 100K on it. I just get them to what I mentioned earlier and as long as they are quiet..I am good with it.
DUB
If we are dealing with a street engine that is not going to be driven like it was stolen and high RPM's all the time.
Back in the day. I was told by the old timers that setting the valve adjustment at one full turn will make it so when wear begins on the rocker arms and lifters. This will make it so the rocker arms will not need to be readjusted as quickly if they were adjusted at 1/2 of a turn.
Kinda made sense when I thought about it. But I do not get all hung up over this adjustment unless it is on an engine that is super high performance.
On an engine with 100K on it. I just get them to what I mentioned earlier and as long as they are quiet..I am good with it.
DUB
05-31-2018, 07:49 PM
#13
Race Director
To get zero play (before doing your 3/4 additional turn) wiggle the short end of the rocker up and down while slowly tightening the adjuster. Spinning the pushrod makes it easy to over tighten.
05-31-2018, 09:47 PM
#15
Melting Slicks
You just BARELY take the up and down slack out of them. You want the cup in the lifter to be at the top with no preload. THEN turn the additional amount. The 1/4 turn was always the plan for something you wanted to try and RPM pretty high. But you have to be careful if the lifters just have little wire clips in them as they can come out if they get pushed against too hard by plunger during a valve float instance or something. Some higher end Morel lifters seem to like almost a full turn to keep them quiet. For normal street stuff that isn't going to be flogged too hard I'd use 1/2-3/4 turn to keep them quiet.
JIM
JIM
Last edited by Buccaneer; 05-31-2018 at 09:47 PM.
06-02-2018, 08:55 AM
#16
Le Mans Master
Need to follow the book on which valves to set and which crank position to be at when you set them.
There are other methods to do this.... if you already know how.
06-02-2018, 10:45 AM
#17
Racer
The easiest and most precise method of finding "0" lash is to use a .001" feeler gauge between the valve stem and rocker arm. With the valve completely closed loosen the rocker adjustment until there is some slop in the arm. at this point slide the .001" feeler between the valve stem and rocker, it should slide back and forth easily. Start to tighten the adjuster until you feel a slight drag on the gauge. Now you have zero lash +.001" When I did my valves 2 years ago I used the opposing cylinder method to adjust the intake then the exhaust second. The opposing cylinders are 1<>6, 8<>5, 4<>7, 3<>2. With #1 fully open #6 will be fully closed and can be adjusted. I adjusted all my intakes first and then all the exhaust. The amount of pre-load will vary with each application. I first set my L48, with flat top pistons, RV cam and ported and polished heads to 1/4 turn and my car didn't like it very well, I then added another 1/4 turn to each rocker and it was much happier at 1/2 turn pre-load. More detailed description of the opposing valve method can be found by a quick Google search. There are easier methods but none are more accurate and this method allows for more hands on time with your engine.
Good luck, Jerry
Good luck, Jerry
Last edited by shenango; 06-02-2018 at 10:47 AM.
06-02-2018, 06:56 PM
#18
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St. Jude Donor '22
funny xhit
you can't get "leverage" with moving around, up/sown, spin, feel
fart on.
i found pushing rockers sucks,
leverage on iffy lifter pump up condition.
you can't get "leverage" with moving around, up/sown, spin, feel
fart on.
i found pushing rockers sucks,
leverage on iffy lifter pump up condition.
09-24-2021, 08:54 PM
#20
