[tm66]

I followed the steps in the manual to tighten the 8 valves with #1 @ tdc, rotate the motor 180 and then tighten the remaining 8. I spun the pushrod till it stopped then added 1 more turn to each nut. The car then ran rough so I backed each nut off 1/4 turn. Everything seemed fine for the last 2 months. I then read a post where you only tighten the nut a 1/4 turn after the pushrod stops spinning with your fingers so I had to tweak. I discovered that I could spin all of the pushrods with my fingers! I followed the procedure again and now the car runs very rough so here are my ?'s:
How do these "loosen" up?
Do you perform this procedure with the motor cold or warm?
How many turns do I add to the nut after I can't spin the pushrod anymore?
Why did the car run better at idle the 1st time when I backed off all 16 nuts by a 1/4 turn?
thanks in advance.
tm

 

[rbeckman]

I followed the steps in the manual to tighten the 8 valves with #1 @ tdc, rotate the motor 180 and then tighten the remaining 8. I spun the pushrod till it stopped then added 1 more turn to each nut. The car then ran rough so I backed each nut off 1/4 turn. Everything seemed fine for the last 2 months. I then read a post where you only tighten the nut a 1/4 turn after the pushrod stops spinning with your fingers so I had to tweak. I discovered that I could spin all of the pushrods with my fingers! I followed the procedure again and now the car runs very rough so here are my ?'s:
How do these "loosen" up?
Do you perform this procedure with the motor cold or warm?
How many turns do I add to the nut after I can't spin the pushrod anymore?
Why did the car run better at idle the 1st time when I backed off all 16 nuts by a 1/4 turn?
thanks in advance.
tm

Tom that is the way I do mine except I got to 3/4 turn and I do it cold and seems to run fine. Maybe I'm just lucky and someone will pop on and have a better way or proper way to do it.

 

[Rich-L79]

First, get the whole "can't spin the pushrod" concept out of your mind, it is entirely misleading and you are misunderstanding what is meant to be done. You are tightening down the rockers too much thus the valves aren't closing all the way thus it will run poorly. On top of that you can at the very least burn your exhaust valves and at worst bend or break a valve when the piston hits the valve. You may have already done some damage.

The first step is to tighten the rocker until you have the lifter at zero lash, THEN you tighten it 1/4-1/2 turn more. Zero lash means there is no play between the ends of the pushrod and the lifter at one end and the rocker at the other (with the rocker also touching the valve stem). Any additional tightening done after initial zero lash is preload and you don't want any preload beyond the additional 1/4 turn. When you "turned the engine an additional 180 degrees" did you turn the CRANKSHAFT 180 degrees or the camshaft 180 degrees? The cam turns once for each two full turns of the crankshaft remember.

Other things to be sure of: The valve being adjusted MUST be closed all the way (the lifter is on the base circle of the camshaft). There are better more detailed methods for insuring the valve you are working on is on the cam's base circle. With hydraulic lifters it doesn't matter if the engine is cold or hot, but doing them with the engine fully warmed up would be better since the lifters will be pumped up and give a better feel of zero lash.

If this all seems a little confusing, it might be a good idea to find someone with experience doing this to show you how to do it and then watch over you while you do a few yourself to get the hang of it. Don't run the engine any more until you get the valves properly adjusted! You could be doing serious damage to things otherwise.

 

[68chevelle533]

One way to set the lash is with the engine running. Back off the nut until you here it tapping, then tighten it until the tapping stops. At this point you have zero lash then you tighten that nut another 1/4-1/2 turn. As you can guess this is messy and you get some oil dripping on the exhaust. I have seen some people put deflectors on the rockers to keep the oil under control or take old valve covers and cut the top off.

 

[rkd]

The spin the pushrod with your fingers method is the one I have the best results with. Did it to my 350 last September and have not touched it since. Seems quiet and runs decently.

However, I have not had much luck with the indexing the cam only a couple times, so I am back to doing it one cylinder at a time, through the firing order. On the 350 I went about 1/2 turn past where the pushrods seemed to resist turning. Note this is with stock flat tappet lifters, rockers and pushrods.

When you check it in the car, unless you are set at tdc on the cylinder you are checking, the pushrods and rockers may seem loose or tight.

 

[Guest]

The old time Mechanics around my small country town taught me how to spin the p/r's as well as lash a solid lifter cam idling fine!

Right, not running, spin the p/r's, running down until they stop spinning ON THE BASE CIRCLE! And running back off until they click, then BOTH CASES down like a 1/4 to a 1/2 rotation.

pdq67

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[OLDED]

Adjust either solids or hydraulics with it idling as slow as it will stay running. It can be messy, but there are the clips you can use to put on each rocker while adjusting to keep the splash to a minimum. An old valve cover with the center cut out to expose the adjustment nuts is good for adjusting hydraulics too. Only do one head at a time, seal up the finished side and go to the other. Solids take a little longer and you need to get the "feel" of the guage pressure to get all the same, but it pays off in the way it runs.

 

[engineguy]

tm,
I agree with previous posts, the valves (when using a stock cam ONLY) can be set with the timing set at TDC #1 cylinder and TDC #6 cylinder. (However, to get from TDC #1 cylinder to TDC #6 cylinder, you need to turn the engine one full revolution, NOT 180 degrees. Find TDC #1 cylinder, line up the timing mark on the balancer, adjust the valves per your manual, then turn the engine one revolution and line up the timing mark again and adjust the remaining valves). In my opinion, this procedure should only be done if the engine has a stock cam. High performance cams have a significant reduction in overlap, which will affect this procedure. Engines with high performance cams should have the dampener marked at 90 degree internals and the valves should be set at TDC by turning the engine 90 degrees and adjusting the valve lash according to the firing order.

Now once the valves have been adjusted cold (aka bench setting), the engine should be started and brought up to operating temperature - then hydraulic lifters adjusted by backing off until ticking is heard and tightened until the sound goes away. Then the adjusting nut is turned the additional turn (s) or fraction of a turn according to cam specs. Yes, it can be messy, but it is the best way to adjust hydraulic lash/lifter preload. Some cam manufacturers specify cold lash adjustment and some specify hot lash adjustment - go by their recommendations.

 

[tm66]

By "rotate the motor 180" I meant that I rotated the motor until the timing mark went one revolution.
Thanks for the posts. I will get er going tonight.
tm

 

[kettbo]

Tom,
The engine must be rotated one full turn to get 360*

Another common mistake is people push down on the handle/socket while tightening...this puts load on the rocker ball....

 

[matt's66]

I like to do mine running like Mike. Very easy. I have a valve cover with the top cut off for this. I get lazy though and just do it real quick without the cut valve cover and the little oil that spills out just burns off. I have seen high pressure high volume pumps squirt oil right over the fenders and even on the hood!

 

[Schurkey]

The spin the pushrod with your fingers method is the one I have the best results with.

The old time Mechanics around my small country town taught me how to spin the p/r's

The problem with this method is that it works OK when you have a real, live, human mentor standing nearby watching and teaching.

When you type it out on the Internet, there's no compensation for oily vs. clean pushrods, and big, strong fingers and a lot of attitude vs. small fingers and a delicate touch.

You end up with some novice that puts a Vice-Grip hold on the pushrod, and he can spin the pushrod until the lifter bottoms ('cause he's totally focused on spinning that pushrod)--and then he adds his "preload".

So it's REALLY COMMON for newbies to get the preload MUCH too tight.

That's how I bought my boat. Former owner was a Ford man; tightened the living crap out of the rocker nuts. Engine wouldn't run. I backed the nuts off about two turns--and "WALLA!" it fired and ran.

The whole point of "zero lash" is NOT to have as your goal that the pushrod won't spin. The point of "zero lash" is when the free play is gone from the valve train. And you're better off testing that by feeling for up 'n' down play in the pushrod; or by wiggling the rocker when the ratchet and socket is REMOVED from the adjusting nut.

 

[tpshea]

The problem with this method is that it works OK when you have a real, live, human mentor standing nearby watching and teaching.

When you type it out on the Internet, there's no compensation for oily vs. clean pushrods, and big, strong fingers and a lot of attitude vs. small fingers and a delicate touch.

You end up with some novice that puts a Vice-Grip hold on the pushrod, and he can spin the pushrod until the lifter bottoms ('cause he's totally focused on spinning that pushrod)--and then he adds his "preload".

So it's REALLY COMMON for newbies to get the preload MUCH too tight.

That's how I bought my boat. Former owner was a Ford man; tightened the living crap out of the rocker nuts. Engine wouldn't run. I backed the nuts off about two turns--and "WALLA!" it fired and ran.

The whole point of "zero lash" is NOT to have as your goal that the pushrod won't spin. The point of "zero lash" is when the free play is gone from the valve train. And you're better off testing that by feeling for up 'n' down play in the pushrod; or by wiggling the rocker when the ratchet and socket is REMOVED from the adjusting nut.

This is absolutely the best advice possible. Do not SPIN the pushrods, simply move them up and down while SLOWLY tightening the rocker nut until they just stop having any play. Then go an extra 1/4 to 1/2 turn.

 

[Wolfplace]

The problem with this method is that it works OK when you have a real, live, human mentor standing nearby watching and teaching.

When you type it out on the Internet, there's no compensation for oily vs. clean pushrods, and big, strong fingers and a lot of attitude vs. small fingers and a delicate touch.

You end up with some novice that puts a Vice-Grip hold on the pushrod, and he can spin the pushrod until the lifter bottoms ('cause he's totally focused on spinning that pushrod)--and then he adds his "preload".

So it's REALLY COMMON for newbies to get the preload MUCH too tight.

That's how I bought my boat. Former owner was a Ford man; tightened the living crap out of the rocker nuts. Engine wouldn't run. I backed the nuts off about two turns--and "WALLA!" it fired and ran.

The whole point of "zero lash" is NOT to have as your goal that the pushrod won't spin. The point of "zero lash" is when the free play is gone from the valve train. And you're better off testing that by feeling for up 'n' down play in the pushrod; or by wiggling the rocker when the ratchet and socket is REMOVED from the adjusting nut.

Excellent advice :thumbsup:

As far as adjusting them running,,
Haven't for probably 30+ years when I learned how to do them correctly without applying a rust preventative to the outside of an engine,,,
Just don't see any reason to make a mess & burn my fingers & it is way to easy to do it correctly with the engine off

Ever been to the drags?
Ever been to a dyno room?
Probably 99% of the performance shops in the country?
How many folks do you see adjusting the valves with the engine running,,,,
But to each his own,,,, :beers:

 

[Rich-L79]

The problem with this method is that it works OK when you have a real, live, human mentor standing nearby watching and teaching.

When you type it out on the Internet, there's no compensation for oily vs. clean pushrods, and big, strong fingers and a lot of attitude vs. small fingers and a delicate touch.

You end up with some novice that puts a Vice-Grip hold on the pushrod, and he can spin the pushrod until the lifter bottoms ('cause he's totally focused on spinning that pushrod)--and then he adds his "preload".

So it's REALLY COMMON for newbies to get the preload MUCH too tight.

That's how I bought my boat. Former owner was a Ford man; tightened the living crap out of the rocker nuts. Engine wouldn't run. I backed the nuts off about two turns--and "WALLA!" it fired and ran.

The whole point of "zero lash" is NOT to have as your goal that the pushrod won't spin. The point of "zero lash" is when the free play is gone from the valve train. And you're better off testing that by feeling for up 'n' down play in the pushrod; or by wiggling the rocker when the ratchet and socket is REMOVED from the adjusting nut.

That is EXACTLY what I was trying say. I'm glad you posted with more eloquence than I did!

 

[tm66]

I went through the procedure w/the motor cold. I took my time, kept my fingers as oil free as possible and wiped the pushrods before turning them. As soon as I felt resistance, I added 1/4 turn. Put it back together and the car would not start at all! Spent an hour checking if it's getting gas, spark, etc (note: the car ran fine before I started adjusting the valves). My last idea was to back the nuts off by 1 full turn to see what happens. Well, it started right up and ran pretty good. I then tightened them 1/4 turn and that's where it currently is.
Now, what's going on? I'm nowhere near where I should be by following the procedure. Any ideas?
tm

 

[Rich-L79]

If it runs fine and you don't hear any ticking from the valve train, just call the job done. You might want to do a compression check on each cylinder to make sure you don't still have any of the valves over tightened.

 

[1965 Blue Malibu]

Tom,
Look at the first blue bar on home page starts with index, news, fourms, go over to (Tech) click on Technical Reference Series, scroll down to engine, you will see adjusting valves, click on that and follow directions.
When I built my engine I used this procedure to adjust my valves, never had a problem. This is the best directions I have seen out there, set them and forget them, you should be fine. :thumbsup:
Bill

 

[RT]

I just brought up this post as I was getting ready to adjust the valves on my 350 SB.
Schurkey's post is very good and I feel confident I can get a good adjustment from that. There's one method I didn't see in any of these posts though, it's a suggestion I'd read in a manual. They suggested using a .o15 feeler guage between the rocker and valve stem to determine the point at which there is almost 0 lash, then tightening from there. Does this method sound like good advice?
Thanks,
Rich