Bit long, pls bare with me lol...
I have recently changed all my valve stem seals and it's time to put everything back together.
Originally, I wasn't going to do the seals, I was just going to do intake manifold gaskets but figured may as well add the new seals while I'm here.
Before that I wanted to clean all the sludge the previous owner had let build up and I wanted to clean the rods too, so before deciding to do the seals I counted each turn to loosen the rockers to turn them away enough to get the rods out so I could just count the turns again to put the rockers back where they were when I was done.

Since then I've turned the crank by hand a few times and basically nothing is in the position it was in when I started all this work. I was going to do the valve lash with the following method..

set cyl 1 at tdc compression, adjust
exhaust: 1 3 4 8
intake: 1 2 5 7

Then put cyl 6 at tdc compression and adjust
exhaust: 2 5 6 7
intake: 4 6 8 3

The problem I have is when I got up to intake on cyl 2, the lifter was so high that basically 1 turn of the ratchet took all movement out of the rod completely, but this leaves no thread sticking out the nut so I know something isn't right.

Basically asking for help cause I don't want to continue if I think it's not right, unfortunately don't have anyone who can help, all my knowledge in regards regards to this comes from what I've read here in the forums and YouTube videos. Appreciate any advice.

 

Or. Do I abandon that method and starting with cyl1 in compression just go one cylinder at a time with 90° turns of the crank in firing order ?

 

Valves need to be adjusted to "zero lash" (take up all the play out of the valve train), then some desired amount of preload added.

Let's leave aside the preload for a moment and concentrate on "zero lash".

Consider a 4-stroke engine such as ours. In an engine of this type, the crankshaft rotates TWICE for each complete "cycle" of the engine. Each "stroke". of the 4, takes up half a crankshaft revolution. If we start thimking about the relationship ("timing") of the various engine parts at the instant of #1 firing, that gives us a good reference.

OK: #1 fires, at (more or less) its top dead center of motion. The piston then begins to descend. During this downward piston motion, called the "power stroke", heat energy released during combustion, produces pressure in the cylinder, which pushes the piston down, which of course generates the desired end result: mechanical power.

Presently, the piston reaches the bottom. At this point, all the energy that can be extracted from the heated gases, has been extracted. The exhaust valve begins to open. The piston passes the bottom and returns toward the top. This portion of piston motion is called the "exhaust stroke".

As the piston ascends, the exh valve opens, and spent gases are pushed out of the cylinder. At roughly halfway up, the exh valve reaches fully open, and then begins to close. Presently, the piston reaches the top again, all the spent gases are pushed out, and the exh valve closes fully. At this point the crank has turned one full revolution.

The piston is now BACK at TDC. But it is NOT at firing again at this point in the engine cycle: instead, it is at the point where the exh valve finishes closing, and the intake valve begins to open. As the crank continues to rotate, the piston passes through TDC, begins to descend with the int valve open, and begins to draw fresh air/fuel mixture in from the outside world. The int valve reaches full opening just about as the piston reaches the roughly halfway down point in its motion. We are now in the "intake stroke".

In good time the piston reaches BDC. Somewhere near this point the int finishes closing, and the piston passes through BDC and begins to ascend once again, compressing the air/fuel mixture in preparation for the next firing event; which occurs as the piston approaches TDC the SECOND time during the engine cycle. This is the "compression stroke".

Note that the crank turned TWICE during all this. Note also that we have some multiple number of cyls, let's say for the sake of argument, 8; and they fire at evenly spaced time intervals. That means, 4 fire during one revolution of the crank, then the other 4 fire during the 2nd revolution. Each cyl fires 90° of crank rotation after the one before it. How simple is that.

Simple enough, no?? Stop now and re-read if you have any questions.

OK now that you've let it all soak in, it should be fairly obvious that any cylinders that are 4 cyls apart in the firing order (for a V8) are doing EXACTLY OPPOSITE things as the crank turns. In a Chevy V8 the firing order is 18436572. This means that as #1 reaches TDC, #6 is ALSO reaching TDC; but when #1 is firing, #6 is at the point where the exh valve is closing and the int is opening. As #8 is doing something, #5 is doing the exact opposite. And so forth.

Are we clear? Stop me if there are any questions.

A camshaft has lobes that are somewhat egg-shaped. They are more or less symmetrical: that is, the "point" of one end (where the valve lift is at its max) is EXACTLY OPPOSITE the "heel" if you will, where the valve lift is ZERO.

Going back to the simple concept wherein cylinders that are 4 apart in the firing order are doing EXACT OPPOSITE things at any given moment, it should be plainly obvious to anyone of anywhere near average intelligence or greater, or even me (who unfortunately is of FAR lower intelligence than that), that when a valve of one cyl reaches its max opening, the same valve on the cyl 4 cyls away in the firing order, is at ZERO.

When #6 intake is at max open, #1 intake is at zero. When #8 exhaust is at max opening, #5 exhaust is at ZERO. And so forth. Too easy.

Are we clear here? Any questions? Stop now and absorb this if you don't already have it etched into your PROM.

So: when you set the crank to the point that #6 int is at full open, then #1 is then at "zero", and can be adjusted. Adjust the #1 int rocker until the VERTICAL play in the push rod is fully taken up. DO NOT try to "twist the push rod"!!!! Look for VERTICAL play in it. When the VERTICAL (up <-> down) play is taken up, it is at zero lash. Adjust the rocker to the point at which VERTICAL play in the push rod disappears.

From that point, rotate the engine exactly 90°, and the NEXT valve of the same type on the NEXT cyl in the firing order (#8) will be ready to adjust. 90° more, and #4 will be at its adjustment point. And so on.

Repeat for the exhaust valves. You don't have to start at #1; just pay attention to whatever one is approaching fully open as you observe them, and adjust the one OPPOSITE IT (4 cyls away) in the firing order, and keep dong that until you've done all 8.

Then when you have finished, add some reasonable amount of preload; let's say, ½ turn. Doesn't too much matter because you're going to re-adjust them after the engine starts up ANYWAY.

The "Chilton's" method of "put the engine here, adjust 8 valves, put the engine there adjust the other 8" is PURE UNMODIFIED UNADULTERATED UNVARNISHED GARBAGE. Might work for someone with VERY low standards of "what's right"; totally inadequate for someone who actually GIVE A $HIT.

Once you have done as described, the engine will run, well enough at least to do lifter break-in and leak-check and all such as that. Reach in the window, crank up the motor, do all that other stuff, and adjust them running one at a time, by backing them off one at a time, tightening them back one at a time until the one you are working on quits clacking, then do the next one, one at a time. After you've done all 16 this way, shut the motor off and add your desired preload. I suggest ½ - ¾ turn for a typical street motor. Put the valve covers back on and begin daily-driving the car.

Questions?

 

Thanks for the detailed response sofakingdom. I will try it how you've outlined, however while I was waiting to see if anyone would respond, I started the #1 @ tdc compression method and and followed the firing order with 90° turns of the crank.
After adjusting #1 I&E I turned the crank 90° and then adjusted #8 I&E, and so on. When I made it to #4, #8 E became loose. After finishing #4 adjustments the crank became very hard to turn, to the point I couldn't smoothly get a 90° turn so I abandoned the task and backed off all the rocker nuts and reset the crank to tdc #1compression, to await some help. (I'll also add that as far as I got the crank to turn, the #4 rods also became loose).

I will now (tomorrow) try your method, but my question is, why did the crank get so hard to turn, why did the other rods become loose, and will I have the same issues when I try the way you have outlined ?
First time doing this, sorry if I come across as a bit of a dumbass 😄

 

You did remove the spark plugs before rotating the crank by hand, right?...

 

yes 😄👍

 

Starting at #1 TDC, whether the firing instance of #1 TDC or THE OTHER instance of #1 TDC, is WRONG. Adjusting both valves at the same point is WRONG. Adjusting both valves at that cyl's TDC, whether the firing TDC or the other TDC, is WRONG. You will NEVER get it right that way. That's why it keeps not working right for you.

You HAVE TO adjust each valve when it's on the "heel" of its cam lobe. If you adjust it anywhere else, it will be WRONG. This point is NOT at TDC, either of them.

Start at the point where some valve is fully open, and adjust the SAME valve on the cyl 4 cyls away in the firing order, to zero lash.

If you do it right, all 16 valves will eventually no longer be loose. You'll find that it's really quite easy once you get going on it.

No idea why the crank got hard to turn, if all the spark plugs are out. There are too many possibilities to speculate on. Valve adjustment probably doesn't have anything to do with it, but it might if you have some that are WAY too tight. Might be best to back them all off and start over from scratch.

 

Follow either of these. It's the same info as Sofa described, just in chart form.

https://www.thirdgen.org/forums/tech...ml#post6304135

https://www.thirdgen.org/forums/tech...ml#post6398435

 

NoEmissions84TA & sofakingdom,

Much appreciate the help guys, although I understood sofakingdom's explanation, the chart really helped make it a little easier to put into practice. I have managed to do it and feel like I've succeeded, however one question remains....
Should there still be some "twisting" or "spinning" movement on the rods once I've completed all adjustments on intakes and exhausts ?
Some still spin (no vertical movement) but a few are tight and will not spin, have I over tightened them and need to ease off a little ? Other than that I feel I'm ready to start putting the car back together.

 

Doesn't matter whether there's any "spinning" or "twisting" action or not. Sometimes there is, sometimes not. Sometimes it depends on whether your fingers are oily or not, or sweaty or not, or whether you have a good angle to grab them. Doesn't matter. Doesn't indicate anything. Doesn't mean anything. Doesn't help with the matter at hand. It is a total detour off the path of correctness. Off the pavement, down the dirt road, through the fence, into the weeds, and into the lake. Failure.

When all the VERTICAL play in the push rod & rocker are EXACTLY JUST BARELY taken up when the lifter is on the "heel" of the cam lobe (exactly opposite the "tip"), then it is at zero lash. Any other condition in any part that might randomly happen to coincidentally coexist at that moment is irrelevant. Once you have attained zero lash as defined by the point at which VERTICAL play JUST BARELY disappears, you are ready to add your desired preload. If you have adjusted them farther than the JUST BARELY GOES AWAY point in the VERTICAL play, then you have gone too far. Have I used the words "zero lash", "exactly", "just barely", and "vertical" enough times yet? Those words are the important ones. "Twist" and "spin" are not part of this vocabulary and are therefore meaningless.

Keep in mind, "play" means just that: PLAY. Looseness. Rattling. Complete freedom to move around without restraint. The reason this distinction is important is, there's a little spring inside the lifter pushing its guts upward. It's pretty weeeeek. It's REAL EASY to mistake an ability to push down on that, with "play". Do not be deceived: depressing the lifter plunger is NOT part of "play". The lifter needs to be allowed to remain fully extended (spring pushing the innards fully upward to the top of their range of motion) during the adjustment process. Tightening until it becomes impossible to "twist the push rod" is almost GUARANTEED to produce erratic, inaccurate, useless, TOO TIGHT results, not least by allowing you to partly or even fully depress the plunger while maintaining the flawed belief that it's not tight enough yet.

You have these 2 simple things you MUST get right: cam on the "heel" of the lobe for EACH individual valve; and the EXACT tightening of the nut that JUST BARELY eliminates VERTICAL play in the push rod. If you get those 2 things right, you are golden. If you don't, if EITHER ONE is not right, you will be in the weeds. It may "run" well enough to get to the next method, but it'll be seriously gimped.

Once you have them set to zero lash, and then added your desired preload (½ to ¾ turn is a usual sort of preference; there's good reasons in some cases for using more or less, but that's the right range most of the time), you can start the engine and adjust them running. Best way to do this is, run it until it's fully hot; pop the VCs off; re-start the engine; adjust each valve, one at a time, by backing it off until it clacks, then tighten until it JUST BARELY stops clacking (this is zero lash again); do all 16 like this, one at a time; shut the motor off; add your desired preload such as ½ turn, or whatever you choose; reinstall the VCs. You can reduce the mess a little by doing just one side at a time instead of all 16 at once if you want but usually it doesn't make all that much difference. DO NOT try to add your preload while the engine is running: it will run terrible for a few seconds each time you crank down on the nut, and may even die; and meanwhile, it'll be running just that much longer without the VCs on, and spewing oil all over hell's half-acre. Set them all to zero lash as quickly as you can, shut it off, THEN add preload.

 

Thanks sofakingdom, I followed the instructions exactly so it looks like I'm good to go.

Should I be concerned if there is no movement in the lifter plungers at all? They are all solid asf, I have read and seen videos where people are able to push down on them a little after reaching zero lash.

As for adjusting while running, it's going to be pretty hard to achieve on my 88 with all the junk that's in the way and sits right on top of the valve covers, so I'm preying I won't have to, but if I do I'll have to figure a way.

 

They generally have some amount of "give" to them, before preload is added. If at least some of them don't, the ones that are on or near the base circle at the moment specifically which should be around 6 to 8 of them, you may have them too tight. You might be able to look down in the push rod hole with a flashlight or something and see if the plungers of ones that are on the base circle, are up very near the little clip that holds them together.

 

 

Having the manifold off, I can see using a light that the seat is a touch under the ring.

 

There you go.

 

Thanks again guys, I'll post back with results when the car is back together.

 

https://www.dragzine.com/tech-storie...sh-like-a-pro/

I've found this method fail proof.

"When the exhaust valve just begins to open on the first cylinder in the firing order, adjust the intake valve by loosening the adjusting nut slightly while spinning the pushrod until you feel lash in the rocker arm. Tighten the adjusting nut until the slack is taken out of the rocker arm and pushrod. Lightly turn the pushrod with your fingers as you tighten the adjusting nut, and you should feel a point where there is a little resistance (this is called Zero Lash). Turn the adjusting nut ½-turn past this point, giving you optimal pre-load for the rocker arm, pushrod and lifter. According to Newman, “you should look for .030-.060 of preload in a typical hydraulic Lifter.” Follow this procedure by carefully adjusting each intake valve according to cylinder firing order.

When all of the intake valves have been set to the proper valve lash, you can adjust the exhaust valves. Utilizing the same procedure as with the intake valves, you need to turn the engine over until the intake pushrod moves all the way up and rotates just past maximum lift. Now the exhaust valve can be adjusted. When all of the intake and exhaust valves have been set with the proper lash, it is common for all the top engine builders to perform a double check by rotating the engine and checking each valve again, starting from the first cylinder in the firing order."Find the sweet spot. David Reher explained, “You’ve got to find that sweet spot where your car runs the best and back it off just a bit. That increases durability a lot and takes almost nothing away from the power.”

Set the valve lash “cold.” Scott Shafrioff reminded, “Cylinders heat up at different rates but cold is cold.” Shafrioff told us to set the valve lash with a cold engine and check the valve lash weekly with the engine at ambient air temperature. This will give you the best indication of when the lash is changing in one of the cylinders.

Ignore the “Chilton Manual” method of setting valve lash. Reher and Musi agree that this method only works for mild street camshafts. The best sequence to use when setting valve lash is to go by the firing order. This requires less turning of the crankshaft and will help ensure that valve overlap is not an issue.

EO/IC rule (Exhaust Opening and Intake Closing). Set the intake valve lash when the exhaust valve is beginning to open. This will put the intake lifter at the base circle which is where you want it to be. Then set the exhaust valve lash when the intake valve is about halfway down on the closing side.

Be Consistent. According to Musi, “Setting valve lash is not rocket science but you can help yourself by being consistent. Check the lash the same way every time otherwise it will be all over the place. You won’t know when you have a problem.”

Check valve lash weekly. David Reher says, “My number one rule of prevention is to never ignore a significant change in valve lash. If one valve suddenly has 20-thousandths more lash than the other valves, find out why. Is the valve bent, is the lifter broken, is the pushrod tip burned up? If you check the valve lash religiously, you can spot these problems before they cause further damage.”

Know what you are dealing with. If you are using trick aftermarket parts like aluminum blocks or titanium valves, follow the manufactures recommendations for maintenance like setting valve lash. The manufacture has already calculated the special compensations for these exotic materials.

 

That's the "EOIC" method. It's a good one; not as precise as the other, but PLENTY good enough for a hydraulic cam, especially when followed by adjusting while running.

A brief look at valve motion during engine operation will reveal why. Peak intake opening occurs not terribly far from the time where the piston is about halfway down the bore during the intake stroke; therefore halfway down the bore during the power stroke is the "heel" of that lobe. The exh starts to open as the piston reaches the bottom of the power stroke, therefore it's pretty close to the intake lobe's base circle. Similarly analyzing the exh lobe's relation to the intake stroke shows the same sort of thing happening with it, at the point where the int valve has passed through peak opening and is just about to close, shortly before the piston reaches BDC and begins the compression stroke.

So yeah, it's a good method, works well and all that. Not as precise to the .001" as the way described above, which is good enough to set solid lifters, but AHELLUVALOT better than that stupid "Chilton's" method of putting the engine here and adjusting 8, then putting it there and adjusting the other 8.

Unfortunately that text still contains the "twist the push rod" thing, which is CERTAIN FAILURE in the hands of an inexperienced builder. The correct indicator of attaining zero lash, once the lobe being adjusted is known to be on its base circle, is to take up all VERTICAL PLAY in the push rod and rocker, as he (and all the rest of us) stated. This is not susceptible to the subjective opinion of the builder as to what "light drag" or "little resistance" or whatever you want to call it, might feel like. IMO any reference to "twist the push rod" in any instructions is liable to send lots of relative beginners into the weeds.

 

Yeah, especially with guide plates rubbing the pushrods. I see your point. Further complicates things when you don't use the right length pushrods. I heard it said for years but didn't believe it. "Once you go to a shaft rocker setup you will never use a stud mount rocker again unless it's a stock rebuild deal" it really simplified the setup process. At least for me it did.

I think many guys get all wrapped up in it and overthink it. Once shown how to do it right by twisting the pushrods between thumb and index finger one time most guys never have trouble again. Especially with a hydraulic roller with stock style lifters.

 

Would be interesting to see some dyno results and long term reliability tests hydraulic lifters with lash at 1/4,3/8,1/2,3/4, and even one turn from zero lash.

They are definitely quieter on the tighter side of the spectrum in my experience. But have often read there is power to be had by going looser. But then again I've read some of vizards stuff saying they are very forgiving, even recently richard Holdener has done testing changing pushrod length by as much as .050 +/- on non adjustable valve trains and saw little difference in over all power output.
I used the delphi lifters on the new 385, initially went 1 turn past zero lash and had no trouble, per my cam grinders advice I backed them off to about 3/8-1/2 turn past zero lash and even cold start in michigan (28 ferenheit) with straight 30 weight oil no real difference in sound. But I'm not over .600 lift. Seems like once you pass that point things get more critical, but the goal then is power and reasonable spring life. I guess what I'm saying is for a street car that isn't going to constantly be revved to 6500 rpm on a typical street strip grind it probably isn't super critical.. hydraulic roller lifters have a pretty wide tolerance where they will run. At least that is how it has been explained to me by many people who's opinion and knowledge I trust completely.

 

What I want to know is......how did the factory adjust them before sending the car out the door? I guarantee they didn't adjust them with the engine running, and it's hard to imagine them spending the time on the EO/IC method on thousands of engines.
And these engines ran 150,000 miles or more without valvetrain problems.
I'm just curious; this is in no way to disagree with what's been said here...

 

Funny you mention that as I was just about to ask a question in relation to that...
Sofakingdom, just wondering, god help me if I do still need to adjust them, how do you go about it with a tpi engine with all the crap in the way of removing the valve covers ? To get mine off I have to pull the wiring harness out of the way, remove the smog pump hoses, possibly even reroute heater tap and hoses and pretty sure i can't remove the left one cause the hard line for the cold start injector is in the way 🤯
Tbh, just preying it's going to be ok lol.

 

Yeah TPI is a bit more of a witch with a capital B... but it can be done. People do it.

As far as how the factory did it, I've never had the chance to watch em actually do it; but I'd suspect they used the 180° method as I described, being careful to leave them a little loose if anything, then added their preload. Which if the FSM can be believed, was 1 full turn. It's really not that hard to do at all when the engine is just a long block and isn't in a chassis or anything.

 

I had a head job done on my wife's 1987 TPI heads earlier this year. I adjusted then with engine in the car. Took out all the lash on half the valves, put in the FSM preload, then turned the engine 360° and adjusted the other half the valves. Didnt adjust each one and turn over, didnt adjust while engine running. Put the valve covers on, installed all the engine components, fired it right up. According to sofakingdom my car should run like crap, but for some strange reason it actually runs GREAT. Dont know, maybe other people know what works too.
To be completely fair though, the cam IS stock.

This isn't the site used for the adjustment reference, but same idea. Contrary to minority opinion it actually works.
http://www.thedirtforum.com/chevyvalves.htm

 

I can't speak for what they did at the factory, but I suspect the adjustment procedure was the same as the GM service manual. Here is a pic of the 1987 shop manual page. Says to set #1 cylinder at tdc, adjust half the valves (per the sequence), turn engine one full turn (360°) and adjust other half. One full turn after valve lash removed. Done. Seems pretty simple.

Page 6A3-9

 

Yeah that's what we call the "Chilton's" method.

Complete and utter GARBAGE for any cam bigger than stock (because the lobes are "wider" and therefore aren't ALL on the base circle at those points), and most especially, for higher RPM operation where less lifter preload is desired. Total lack of precision.

Works well enough for cams like the stock "peanut" cam (typical TPI / TBI / LG4) or the old 929 (smogger cam from the 70s) if you have low standards and/or are working flat-rate. TOTALLY inadequate for anything much bigger than that. TOTALLY inadequate for anyone that wants PRECISION and ACCURACY.

 

Well all back together and so far so good, no noise from the rockers while its been idling in park and sitting in drive in my garage, once I flush out and give the cooling system a good clean I'll do a road test. Thanks for all the help.

 

If you are completely confident with Sofa's method that you used, and the engine is running correctly, then you do not have to do the tick method with the valve covers off.

 

I'm hoping so. I'll see how it all goes in the next few days.