valve adjustment confusion

[crm318]

i am currently installing a cam into a 350 and reverted back to an old question i posted a while back when i was doing the same thing. heres the post
http://www.67-72chevytrucks.com/vboa...ain+adjustment

if you look at posts 7 (corn) and 8 (rage n rat), they both show the valvetrain sequence, but they are completely diffrent from eachother. one of them is incorrect.

the problem now is that i adjusted them according to the # 8 post and my engine has valvetrain noise and the headers glow red hot. did i get screwed on this? im looking for expert advice on this one.

[2nd_wnd]

I adjust mine according to post #7.

be sure you are at TDC #1 when you start

[cdowns]

rage-n-rat is word for word number by number out of the factory service manual (a bargin at about $25 from all vendors)

[Steelawork'n]

It's really not that hard. I did mine while it was idling. First you need to get some spray deflectors from NAPA to control oil spray from your lifters. Next, you loosen them carefully until they begin to rattle. Then, you tighten them slowly intil they stop being noisy. Then tighten them no more than one full turn. I do one side and put the valve cover on and then do the other side. There is no order, just one by one. Sometimes when you get a new engine, the first start is with the valves loose.

You more experienced guys might have special tools for this, but I've always done it and seen it done with the engine running. I have over 200k on my engine with no problems.

[crm318]

well im getting different answers on this from people who are certain, which has been my demise from the beginning. im not trying to discredit anyone, but i have to be certain.

[whatnow123]

Well, I did mine by adjusting the opposite valve when the other started opening. Worked just fine.

If your headers got hot, it's probably timing more than valve adjustment. I'm guessing it's way advanced.

[Steelawork'n]

On post #7 he talks about wet adjustment. That is the method I described. When you do it "wet", you really get a feel for the proper tune. You can actually hear a feel the engine gradually begin to run properly. While SBC are forgiving, don't gun the engine while doing this adjustment. The wet method only takes about 15 minutes and you're ready to roll.

[cdowns]

one sure way buy service manual read service manual

[Billla]

Post #7 is what I use - the companion cylinder method. It's worked for me a few hundred times

Our old pal Mark has the intake/exhaust reversed - right cylinder numbers, wrong valves.

There's no reason to adjust the valves with the engine running IMHO.

[Steelawork'n]

Originally Posted by Billla

Post #7 is what I use - the companion cylinder method. It's worked for me a few hundred times

Our old pal Mark has the intake/exhaust reversed - right cylinder numbers, wrong valves.

There's no reason to adjust the valves with the engine running IMHO.

Nothing like handling hot oil...nothing like it at all

[Highsteel]

Wet method here, you simply can't mess it up. (Unless you don't have the rocker clips, or an old valve cover with the top chopped off!)
Sixteen valves adjusted and down the road in about 15 - 20 minutes. Its how my Dad taught me in the '70s. (",)

[Green Machine]

I like the cold not running method - but i do it running wih the old cut valve cover if there is a possible problem-

From Chilton manual the greasy page I always use-
No 1 firing position - balancer at 0 deg

exhaust 1 3 4 8 intake 1 2 5 7

No 6 firing position - just set the rest that are loose but for the record -

exhaust 2 5 6 7 intake 3 4 6 8

[redhead69]

I went down this road when i got my motor going and the answers I got from mechanics is- use the dry method to get it going and close, and the wet method for a final adjustment. There reason was the hydraulic lifters need to be pumped up (full of oil) to get the accurate reading. Running, they are pumped up.. makes sence to me. I tried the deflectors from napa and another brand as well--big freakin mess!! oil on the headers = major smoke screen! PITA it will still drip. I cut up a set of valve covers as mentioned and did one side at a time. I can take a pic of the valve cover if you need so you get an idea. This was on my first motor build and was freakin out over every little sound and wanted it perfect.. I know your frustrations! Anyway just my .02

[Boog]

Red brings up another important item. If you are replacing the cam and lifters the lifters will need to be pumped up to get your proper valve adjustment. Running engine pumps them up. With the running adjusting method you near bouts can't get it wrong. Zero the lash and turn slowly up to one turn more. That's it, it's done, put the valve covers on it and wipe it down cause it's ready to roll out the door!

[Billla]

The valves should be adjusted warm just because the clearances change, but there is no "pump up" of the lifters. If you take a hydraulic lifter apart you'll see how that just isn't possible. With a spring pushing the cup up to the limit of it's travel, what exactly is going to "pump up"?

Look at what the race shops do - how many of those do you see adjusted running? Zero.

It's always a charged discussion

[redhead69]

Billa you helped me with my motor (thanks by the way!!) and am throwing a few things out to try to learn more so heres a passage out of a book I got

"The operation of the hydraulic lifter is simple. When the lifter is sitting on the base circle of the cam lobe (valve is closed), it fills with oil from the lube system under the plunger. When the cam lobe moves under the lifter (valve begins to open), the oil becomes trapped in the chamber under the plunger. This takes up the clearance in the system, eliminating noise. When the lobe moves out from under the lifter the chamber is opened again to oil pump pressure, and new oil is pumped into the lifter. At the same time, the spring load under the plunger forces it up against the pushrod (or valve).

So its full of oil right, and not sealed but open to new cycling oil so they bleed off and pump up ?? or am I lost in this one

[cruiserman]

Originally Posted by redhead69

I tried the deflectors from napa and another brand as well--big freakin mess!! oil on the headers = major smoke screen! PITA it will still drip. I cut up a set of valve covers as mentioned and did one side at a time. I can take a pic of the valve cover if you need so you get an idea.

Yes, I would like to see a picture.

[70GMCer]

Originally Posted by Steelawork'n

It's really not that hard. I did mine while it was idling. First you need to get some spray deflectors from NAPA to control oil spray from your lifters. Next, you loosen them carefully until they begin to rattle. Then, you tighten them slowly intil they stop being noisy. Then tighten them no more than one full turn. I do one side and put the valve cover on and then do the other side. There is no order, just one by one. Sometimes when you get a new engine, the first start is with the valves loose.

You more experienced guys might have special tools for this, but I've always done it and seen it done with the engine running. I have over 200k on my engine with no problems.

Old school.......bottom line.....IT WORKS BEST.....

[Billla]

Originally Posted by redhead69

Billa you helped me with my motor (thanks by the way!!) and am throwing a few things out to try to learn more so heres a passage out of a book I got

"The operation of the hydraulic lifter is simple. When the lifter is sitting on the base circle of the cam lobe (valve is closed), it fills with oil from the lube system under the plunger. When the cam lobe moves under the lifter (valve begins to open), the oil becomes trapped in the chamber under the plunger. This takes up the clearance in the system, eliminating noise. When the lobe moves out from under the lifter the chamber is opened again to oil pump pressure, and new oil is pumped into the lifter. At the same time, the spring load under the plunger forces it up against the pushrod (or valve).

So its full of oil right, and not sealed but open to new cycling oil so they bleed off and pump up ?? or am I lost in this one

Glad I could help with the engine!

We're all learning all the time. There are a couple of key points in that description, but apply it to the picture I posted. If you've never monkeyed with a lifter, go get a junk one and take it apart to see how it REALLY works!

The spring presses the cup up against the very top of the travel - at rest, with no oil flow, that cup is going to be as high as it can possibly go. When it's warm, the whole lifter will be a bit taller due to thermal expansion, but regardless of how much oil is in it that cup CAN'T go any higher - fair? The oil just provides assistance to the spring at higher RPM; a spring that would work at 5000 RPM would be too much at idle...this is the beauty of the hydraulic lifter - adjustable tension. The description is right on, but it describes operation at speed, not when the engine is off.

When we do a static adjustment (of a warm engine), we're setting preload against the pressure of that spring - that 1/2 turn (or whatever the cam manufacturer recommends) pushes the cup down against the spring. Ultimately, that's what we're after in this whole process - the RIGHT amount of preload. Too little, we have clearance and so clatter...and we're beating on the lifter, cam, pushrod and valve stem tip. Too much, and and the system "goes solid" - there's zero clearance and something has to give - usually the lifter and cam lobe, but sometimes the pushrod, rocker or even valve stem.

When we do a "dynamic" adjustment (engine running), we're pushing against a lifter filled with oil in addition to the spring. The lifter isn't "pumped up" - because the cup can't move any higher in the lifter body - but we're setting preload against the spring AND oil pressure. IMHO, this situation makes it easier to add too much preload and it's also error prone...because rather than having a relatively precise means of determining zero lash (pushrod "drag"), we're doing it "by ear" - we're listening for "clatter" and then adding preload. Also, as a newbie - if you screw up and add too much preload (you'll hear the engine bog or stall) - it's too late - you've likely already caused damage at the lifter/cam interface that will show up later as a wiped cam lobe. I see it all the time. There's a fair amount of "give" in a stock or aftermarket lifter, but as we start getting into aftermarket, higher lift cams my experience is that the adjustment becomes more critical - and the flaws in "dynamic" adjustment become more apparent. Finally, you're working under the hood with oil flying and dripping, smoke from oil on the exhaust manifolds and very aware that getting a finger in the wrong place is going to be painful. No thanks.

For all the debate, the fundamentals are simple; we need to locate zero lash, and we need to set the appropriate preload. To do this, the valve needs to be on the base circle of the cam, it needs to be warm, and we need to fairly precisely find zero lash...which for all the jokes is done very easily by a newbie by just spinning the pushrod while slowly tightening the rocker nut...and the FIRST TIME DRAG IS FELT we have zero lash. Once you can determine that reliably...everything else is easy.

IMHO, the "old way" may work, but if it was "better" I can assure you that you'd see the crate engine companies, racing teams and engine dyno guys using it - and they don't.

[Green Machine]

The main advantage as I see in doing the valve lash running, is if you have older lifters that may have some varnish or buildup of some kind on the lifter. Sometimes we are working with engines that still run but are 40 years old. You really can't count on the spring in the lifter to push the cup to the top on an older engine that could have some varnish. The additional oil pressure during running can help to position the cup at the top of the travel. Sometimes you have to run it a little loose and let it tick/hammer a while to free up the lifter.

When adjusting warm and running, when you back off the nut, you can tell roughly how much preload was there.

[68GMCCustom]

I'm afraid I may be dealing with the results of the valve lash adjustment being set while running. I'm afraid one valve was tightened too much and did some damage but am not sure. I'm planning on doing a static adj. today and see what the results are.

[Billla]

Originally Posted by Green Machine

The main advantage as I see in doing the valve lash running, is if you have older lifters that may have some varnish or buildup of some kind on the lifter. Sometimes we are working with engines that still run but are 40 years old. You really can't count on the spring in the lifter to push the cup to the top on an older engine that could have some varnish. The additional oil pressure during running can help to position the cup at the top of the travel. Sometimes you have to run it a little loose and let it tick/hammer a while to free up the lifter.

When adjusting warm and running, when you back off the nut, you can tell roughly how much preload was there.

The cup is moving all the time in the lifter, so that area is actually very polished. Again - take a lifter apart sometime and see. IMHO there's no way any type of varnish buildup could prevent the cup from moving up. Also, that spring is pretty healthy I guess if the lifter is just completely shot you could have a broken spring or one that won't hold the cup up...but IMHO that's a lifter that isn't going to be able to have lash set consistently regardless. And of course this "advantage" doesn't apply to newer engine.

A sticky lifter is generally caused by junk in the lifter - often junk coming from underneath the heat shield (see pic). You can use chemical to try to get it out or beat it out by leaving the lifter loose...but this has nothing to do with valve adjustment.

The assumption in the preload comment is that the right preload was already there...and in that case, why are you adjusting the vavles?

[70rs/ss]

Billa, i am with you 100% on this one!! I know you think I don't but in my own way I am with most everything you except I don't mind dropping the $$$ for a "fancy" part even if it is just for looks!!



I did it the "old" way forever, then looked into the static (non-running) and I'll never go back. I don't know how I never KO'd a motor on initial startup waiting for it to run to adjust the valves. I can set the valves on the engine stand before it is even in the vehicle, and with 1/2-1 turn it'll fire and run like a top, ready to break in the cam. BTW hot oil is not good for the skin!!

[Green Machine]

I agree that setting lash static is the easiest and the least messy, but I have to disagree that even though the cup may move a little while running, it should not come to the top against the snap ring while running. If it does then there is a problem. 1/2 turn equals .020 preload, so it might move up or down .005 while running. That still give around .015 to the top which very well could be varnished up and will not give with spring pressure alone.

Yes if they are that dirty/sticky they should be replaced, but on an old motor, unless you take the intake off and verify the cup hits the snap ring, the surest bet in my opinion is to set them running. Newer engine or good lifters, I always avoid the mess and do it not running.

[Billla]

I guess when we get into thousandths of an inch, you're right. Given that we're listening for clatter by ear, that level of precision seemed out of place

I do hear you, and as long as it's given good results for you that's all that matters