BOTTLEDZ28

iTrader: (9)

I need to reinstall the heads on my car and will need to adjust the valve lash. Ive never done this before and have heard of a few different ways to do it. has anyone used the method in this link?

http://www.centuryperformance.com/va...procedure.html

cardo0

No! My FSM adj cyl #1 at TDC plus half the valves. Then 1 full turn of the crank and adjust the rest of the valves. Also use 1 full turn pre-load.

I don't like how that century w/s has you looking for "max lift". And small 1/4 turn pre-loads reduce from your valve/cam lift and only helps if you over rev the motor and it starts to float the valves.

midias

Never tried that I always do the EOIC method then tweak the one or two that make a little noise while the engine is running usually another 1/8 to 1/4 turn. I adjust the poly lock until I start to feel a little resistance on the pushrod then I use 1/2 turn preload which is right in the middle of the 1/4 to 3/4 range comp suggests for their lifters.

http://www.compcams.com/v002/Pages/4...cLifterPreLoad

I am basically copying the crane method which is the EOIC method

http://www.cranecams.com/pdf-tech-tips/hydro-lift.pdf

sofakingdom

iTrader: (1)

That is BY FAR the most accurate way to adjust valves. It's the method I prefer, and have posted myself many times over the years.

THIMK... cyls that are 4 apart in the firing order, in a 8-cyl engine, are EXACTLY OPPOSITE each other in every way at all times, except piston location. Their pistons always move identically, but their valve events are exactly 180° apart. So... you're wanting to adjust the valves; you want to find the "zero lift" point; where on the lobe do you suppose that is? EXACTLY 180° away from "peak lift", no? And what else is happening at the instant that any given cyl's valve is at "zero lift"? Why, the one 4 cyls away in the order has that valve at "peak lift". Total no-brainer to see why this method is THE MOST accurate that there is.

EOIC is similar; it's based on the relationship of the 2 valves in the same cyl instead, though. It's not quite as dead-on-***** accurate as the other, but it's PLENTY close enough for most people most of the time. Even for most solid cams.

That stooooopid FSM/Chilton's method SUCKS. If there is any one method I WILL NOT USE, EVER FOR ANYTHING, it's that one. It's totally inaccurate, and is only good enough for factory peanut HYDRAULIC cams and very high values of preload (high enough that the VAST inaccuracies caused by having most of the valves well off of their base circle are swamped by the preload) when the finesse of the finished product is unimportant. (grandma's grocery cart) It is COMPLETELY unusable on ANY mechanical cam.

Ignore the crappy Chilton's method and use one of the other 2.

AlkyIROC

The procedure in that link looks very complicated. It's always difficult to know exactly when each valve is in the proper position and you're constantly turning the crankshaft. I prefer do do the single rotation method and use the timing pointer as a reference.

Bring the timing mark up to TDC. Determine if it's #1 or #6 TDC. Adjust half of the valves. Rotate engine one full revolution and adjust the other half of the valves.

My engine has a really big camshaft in it and I can still adjust all my valves doing it this way.

With a normal firing order of 18436572 you adjust the valves like this.
#1 TDC
INT 1,2,5,7
EXH 1,3,4,8

#6 TDC
INT 3,4,6,8
EXH 2,5,6,7

My camshaft has the 4/7 lobes swapped so on a 4/7 camshaft the order is slightly different

#1 TDC
INT 1,2,4,5
EXH 1,3,7,8

#6 TDC
INT 3,6,7,8
EXH 2,4,5,6

Every valve you adjust using this procedure is on the base circle of the cam.

Solid lift cams use a feeler gauge to set the adjustment. Hydraulic lifters are all the same. Turn the rocker nut just until you get to zero lash then 1/2 turn more to set the preload inside the lifter and move on to the next valve.

sofakingdom

iTrader: (1)

I NEVER EVER EVER FOR ANY REASON AT ANY TIME ON ANY CAR use that Chilton's method.

It's simply not accurate enough: way too many lobes are not on their base circles, but rather, are halfway up the ramps.

Even a lame stock peanut cam motor will run better with the lifters all set to the same preload, than it will with a sloppy job like what that flat-rate method produces.

The most important thing about getting accurate valve adjustment is ACCURATELY GETTING ON THE BASE CIRCLE. The next most important thing is consistency of technique in the setting: assuring that the lash is correct and consistent for solids, and making sure to get exactly at "zero lash" of hydraulics (all play in the push rod & rocker removed, but the lifter plunger not depressed) then putting consistent preload on all.

The procedure in the link is EXTREMELY simple and easy. Once you find the 1st valve of a given type, say the 1st intake valve's peak, then you just go through the firing order starting there and turning the crank exactly 90° each time. Not necessary to individually observe every valve to verify its peak lift.

cardo0

You're right and the FSM as well as plenty of other publications are wrong? Com'on! This is getting funny.

OrangeBird

iTrader: (1)

The man is 100% correct that not being on the base circle is likely the biggest mistake folks make when valve adjustment ends up going wrong . I believe what he's saying is that although the other methods can get the job done they are far easier to cause mistakes than the method he proposes . I guess to some folk's way of thinking one method may make more sense to them than a method that makes sense to someone different , and I do agree with him that the method he proposes is the one I've used all these years (on automotive engines) and to me is the one that best assures proper results .

BOTTLEDZ28

iTrader: (9)

Thanks for the feedback guys. I will attempting the method in the link I provided. Anyone tips or things I should look for when doing this? I know the directions say to do it on a warm engine but I really dont want to fire this thing up with valves that are not adjusted.

midias

Do it cold that will get you close then you can do a hot adjust while running or repeat after warm

AlkyIROC

When people mention a cold valve set, it means when the engine is between freezing and ambient temperature.

BOTTLEDZ28

iTrader: (9)

Doing it while the engine is running isnt going to happen unless I cut windows into a spare set of valve covers so that hot oil doesnt splash all over my new stainless headers. I know some people make shields out of cardboard and lay them on the headers but Im taking the chance of them staining the tubes or even worse, smoldering and catching fire.

sofakingdom

iTrader: (1)

Yup.

Factory service manuals are designed for FACTORY technicians (at dealerships) working on FACTORY engines, in the first few thousand miles of their lives, to get them back to FACTORY "specs".

Which of course, every "performance" engine builder is in a big hurry to make his car exactly back like "factory"; since that represents the very pinnacle of extracting every last ounce of power from any given motor. After all, 165 HP out of a 350 is enough to win a heads-up drag race, no???

They are NOT designed as the absolute last word on every detail of PERFECTING every engine in every application with every kind of part available in the aftermarket.

The FSM valve adjustment method works well enough to get a peanut-cammed motor with all of the usual factory sloppiness back out the door quickly. That's ALL it's designed for.

Do you want your engine to run PERFECT, or do you want it to run like some FLAT-RATER power-slammed it in an hour under book time?

ATTENTION TO DETAIL is one of the main reasons that one builder can take a given parts list, and BLOW AWAY the guy in the next lane who took the exact same parts and just slapped em together. Why for example, the Edelbrock "RPM" package might make 425 HP or whatever they say it does when THEY build it and dyno it, but barely cracks 300 when yerbasic street-stroke just jams it together.

I really don't care whether you think it's "funny" or not. Go give ATTENTION TO DETAIL a try and see for yourself.

cardo0

That method of yours is by no means the optimum for performance. But the FSM method works well for someone that has never done that before. Reality is someone that really knows what they are doing won't be asking. They can adjust a hydraulic lifter piston/plunger travel to less than 0.020". And no way I would encourage a beginner to try that.

That's a real problem on forums as those with some amount of experience and plenty of over confidence will lead a newbie right over the cliff trashing therm brand new rebuilt motor. And who's gonna pay for that? Not Mr. Knowitall!!!

sofakingdom

iTrader: (1)

Well then by all means, tell us what IS. Let us in on YOUR "secret" for assuring that, NO MATTER WHAT, you're always adjusting the valves ONLY when they're on the base circle.

Not sure where the rest of your ignorant uninformed rant is coming from or going to...

Please just go out and build your factory-duplicate 165 HP 350 motors using factory service manual FLAT-RATE techniques and lose lots of races and don't impede people who are trying to learn how to do things BETTER. Especially since, the person who originally asked the question at hand, ISN'T a "beginner", like you.

John in RI

iTrader: (167)

Don't be intimidated by this process, it's really VERY simple. Really no reason to over complicate this very simple task. While I have the picture in the link below burned into my memory,... I always print out the pic and let it sit in the lifter valley as I'm setting the rockers so I can quickly confirm my memory as I go. I also check off each rocker once it's set so I can walk away if needed and will know exactly where I left off when I return.

http://berlinetta.info/Lash.htm

A few things to mention:

Don't SPIN the rods to find Zero Lash ! Quite often a push-rod will continue to spin, even AFTER zero lash is reached. Pinch the rod tight between your finger and thumb and move it UP/DOWN as your tightening the rocker until it no longer 'clanks' between the lifter and the rocker. ( I wrote "can no longer "clank" between the VALVE and the rocker." by mistake It should read; "can no longer "clank" between the LIFTER and the rocker." )

The FACTORY FSM calls for 1 FULL TURN after reaching zero lash. If you are installing new lifters,.... Follow the manufacturers' instructions regarding pre-load ! ( If your re-using used lifters, I'd suggest 3/4's-to-1 full turn. )

Soak all lifters in oil before installing them into the block.

While it's "ideal" to set each rocker when each cam lobe is set to it's base circle.... ( Start @ #1, rotate 90 degrees do the next, and on and on,.... ) for a first-timer it's more complicated possible to loose tack of where you are in the process using that method. (unlike a "professional" that has set pre-load 100's of times that way.) That method is NOT mandatory in order to properly set the preload. I've followed the FSM instructions to install new Rockers/Lifters on literally dozens of SBC's and have NEVER had a problem. Roller rockers, stamped steel rockers, self & non self-aligning rockers, hydraulic flat tappet, roller lifters,...... NEVER a problem when following the FSM/Chilton's instructions.


Edit: Sure sounds like a beginner to me.

BOTTLEDZ28

iTrader: (9)

Im no beginner when it comes to these cars. Ive just never had the pleasure of adjusting valves on a SBC before. There is a first for everything. I made this thread to get advice from those of you senior members who have done the job before. Nothing wrong with getting tips from members who are experienced with the procedure. Can I do the job, absolutely. Am I a novice around these cars, absolutely not.

John in RI

iTrader: (167)

That's all I meant,...... & hope it was taken that way !

cardo0

If you have never adjusted lifters before then I recommend you take the time to get familiar with the lifter/plunger. For a roller you need to somehow secure it as you take a p-rod and try to force that little cup down into the lifter. This will show you how strong the little spring holding the cup really is. You should realize what to expect when setting zero lash. Myself I have never been able to even move the cup at all though others say it collapses easily. You really need to see this for yourself and decide yourself if you need any "pre-lube" or "pump up".

Also if you study the firing order enough you will realize every 90 degrees of crank rotation there are 2 cylinders at TDC but only one cylinder is ready to fire with both valves closed and their lifters are on the base circle. Those lifters have to be on the base circle -- no exceptions!. This closing of the valves follows the firing order with each cylinder getting its own turn with 2 full turns of the crank for all 8 cylinders (each 90 degrees apart). If you study this order you won't be fooled which lifters have to be on the base circle .

Hope this can help and good luck.

BOTTLEDZ28

iTrader: (9)

John, you had mentioned that the lifters should be soaked in oil prior to going this job. Were you referring to new lifters being used? I'm reusing the original lifters. Would I still need to remove them and soak them for one day??

OrangeBird

iTrader: (1)

I know you specifically asked John , but if the question is open to anybody I'll tell you that no , you do not need to remove them and soak them in oil if all your doing is R&R of the heads and then reassembling the pushrods & rockers back onto them .

John in RI

iTrader: (167)

Best bet is to leave original lifters in place so they remain on the same cam lobe that they were always touching. Really not a good idea to mix them up; I even prefer to leave original roller lifters in place even though it's not nearly as important as when dealing with flat tappet.

Supervisor42

The most important part in doing this is it will spot the lobe base circles when the cylinder is under max pressure.
When the opposite cylinder in the firing order is in cross-over (exhaust closing, intake opening) the cylinder you are adjusting is under max pressure and that's when lash is the most important.
And it works for any cam in any 4-cycle engine.
So many cams have gradual ramps to take up the slack in valvetrain to eliminate metal-to-metal impact that they are not on their base true base circle until the cylinder is under max press.
They are either on a slow ramp up to take the hammer effect out, or they are on a slow ramp down to keep the valve from bouncing on the seat.

Quick and easy:
Exhaust valve just finished closing on a cylinder, set the valves on the opposite cylinder in the firing order. Turn crank and watch the next cylinder's exhaust valve in the firing order close, then do the cylinder's valves opposite it in the firing order.

Example:
Firing order:
1-8-4-3-6-5-7-2

Exhaust valve finished closing on #6, set lash on both valves on #1.
Turn crank and watch #5 exhaust valve close completely, set lash on valves for #8.
Repeat for the rest.
Roll thru them again and double-check.

Works for 2 cylinder motorcycles up to 16 cylinder diesel engines.

(off topic: Sofa, are you as old as me? I'm getting old Somebody's gotta teach these damn kids when we're gone)

scoflaw

iTrader: (2)

X2. Big or small cam this method works. Solid cams are the true test. Too tight or loose it would be evident immediately
The base circle is almost 180 degrees of the cams revolution. Doesn't have to be perfectly on the heel

Supervisor42

Wrong. It does.
That method is straight from the factory assembly line for stock hyd cams. I've used it before. It ends with: "now add one-half turn to put the hyd lifter plunger in the center of it's stroke". That's the great equalizer.
If the valve train loosens up, the plunger moves up, if the valve seat sinks, it can move down.

Even this lame 280° cam is only on it's true base circle for only 80° (360-280=80).



There is no way you can adjust 8 valves with this engine in 1 spot and most of the lifters not being on either a ramp up or ramp down.

Edit: Think about a diesel for a second; there is no distributor cap to remove, no sparkplugs to take out, and no timing pointer or marks. How do you think we do those?

BOTTLEDZ28

iTrader: (9)

Update guys.. yes its been a litttle while but I had a small issue along the way. I think its corrected now. Anyway, I opted for the method that John has posted with his link only because I figured it would be a good baseline to start with and get the lash close enough so I could at least start the car. I did a 1/2 turn which resulted in a few of the rockers ticking a bit on the passenger side. It had to be the side that is hard to remove the cover on too. I gave those another 1/4 turn and all was good.

The issue I ran into was the #7 header was beginning to get a little red. This same issue showed its ugly face last month and forced me to pull the heads and have them checked out by a local shop. They replaced the exhaust valve for that cylinder and did the seals. I put it all back together and and the stupid tube was still turning a tint of orange. I backed off all the rockers and did a leakdown test. That checked out. I then redid the lash using the same method as before but this time I only went 1/4 turn and fired up the car without the covers on. I was shocked when none of the rockers were ticking. I backed off a few of them to see just how far I could loosen them before they began to tick and most of them was a 1/2 turn loosening them. So, I put them back to zero lash and then a 1/4 turn but also gave them another 1/4 turn to see what would happen and the engine lost a little RPM and smoothness to it. It was weird. I took that extra 1/4 turn out and the engine responded back with a smoother idle and a few more RPM.

So right now, the lash is set to 1/4 turn and none of them are ticking. I let it idle until it got up to temp and they still didnt tick. I cant hold a higher RPM because the covers are off and the oil will make a mess. Ill put the covers back on and see how she runs after I put a few miles on her.

As for the header tube getting a little orange..I still have no idea what causes it the second time around. First time was most likely the ever so slightly warped valve. That cylinder gave me 119 psi vs 180 on the others.

I'm thinking that I may have tightened the rocker nut too much and caused the valve to never fully close. I can't confirm that though. Or, I have a vacuum leak somewhere in the TPI for that cylinder. The tools will be putting in some work this week and hopefully I can finish this job and call it a day before the winter sets in.

Lamont814

Great explanation. However I'm confused about piston location. One of the other comments said when one is at peak lift the other cylinder would be a max pressure. Peak lift in my understanding would mean that the piston is at the bottom of the intake stroke. Max pressure in my understanding means piston at TDC on the compression stroke. So I'm visualizing one piston at the top and the other at the bottom. Could you straighten me out ? Thanks 😊

sofakingdom

iTrader: (1)

Peak lift does not occur at the bottom of the stroke.

Think: let's look at, say, the intake stroke. When the piston is at the top, just finishing the exhaust stroke, the intake valve just begins to open. It continues to open more as the piston descends, then begins to close, and closes fully when the piston is somewhere near the bottom, which is the beginning of the compression stroke.

The exhaust follows a similar discipline, except it opens at the end of the power stroke when the piston is at the bottom, and closes when it reaches the top, at the beginning of the intake stroke.

Max lift for each valve occurs somewhere roughly near when the piston is at the halfway point.

All of that about "max pressure" is irrelevant and has nothing whatsoever to do with valve adjustment. I'm not even sure what that person was talking about, it makes no sense to me at all.

The object of the exercise remains, to find the point for each individual valve when ITS cam lobe is on ITS base circle, Only ONE valve at a time is ever actually perfectly exactly at this point. A few at a time may be "close enough for gummint work" if you're not too picky. NO WAY 8 of them (FSM and Chilton's method) are close enough to that all at once for anybody with more dignity and perfectionism than a flat-rater driven from behind with a whip by a service manager who has a bonus determined by how much the poor tech can beat book time by.

Lamont814

First let me thank you for such a prompt reply. It's greatly appreciated. I sat around after I posted my question and began researching when the intake starts opening and found that it's well before BDC. The only thing I could think was maybe max lift actually is somewhere near the middle. The MAX pressure thing threw me off. I will definitely be using this method of valve adjustment moving forward. Best of wishes to you. 🙂🙂🙂

Lamont814

I sent a reply but don't see it today. Just in case you didn't receive it thank you for your response and explanation. It is greatly appreciated.