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Valve adjustment

3K views 21 replies 13 participants last post by  rkd 
#1 ·
Just wanted to share a way to adjust valves on a Chevy engine. Now keep in mind I seen this on YouTube. I typed in “454 valve adjustment” and the video showed up. I’ve alwsys done it the way the book says but this was interesting and sorry but I don’t know how to post a link. Anyway the fella says he’s been doing it that way for over 30 years. Says start by installing push rods and rockers. Then on the loose push rods tighten down until lash is taken out, then spin crank 90 degrees and take lash out of loose push rods. Spin another 90 degrees and do it again. He said do this for two full rotations to double check. Once done take every rocker arm nut and tighten down 3/4 of a turn and it will be perfect no matter where the pistons are in relation to Tdc etc.... makes sense I guess but I’ve never tried it.
 
#2 ·
Sounds like a "good enough" way to do it on farm trucks. It's not exactly wrong but it doesn't really take more time to do it with the IO/EC method. A lot of builders will tell you 3/4 turn is WAY too much, also.

But I'm not a builder, just a guy that listens to the professionals. Anytime someone starts out by telling us that they've "done it this way for 30 years" I proceed with caution. With startling regularity it is revealed by the professionals that the guy has been doing it wrong for 30 years. There's guys out there that have been adjusting valves on running engines for 30 years, though not when first assembling an engine but you get the point. That's another "good enough" way to do it but there's a better way.
 
#14 ·
Actually doing it by the book works fine with a stock cam.
Been doing it that way for 30 years.:D

The IO/EC method is really only needed for non stock cams

Nothing to add except it's EO/IC, not the other way around. ;)
 
#7 ·
I have used degreed balancers with marks for 0, 90, 180 and 270 degrees for decades. I set solid lifters by turning the crank to all 8 firing positions (720 crankshaft degrees) and setting both valves of each cylinder when the crankshaft is in firing position (TDC on compression stroke) for that cylinder. One could do the same for hydraulic lifters.
 
#11 ·
"Sounds like a "good enough" way to do it on farm trucks."

All normal passenger car engines might as well be farm trucks. The method listed does work. If you aren't trying to get the absolute most performance out of an engine, what difference does it make how perfect the adjustment procedure is done as long as the engine functions normally. Same goes for degreeing a cam. So you degreed it. BFD. If you aren't going to ever advance or retard it to see what difference the changes make, who is to say that where you put it is the best setting? Bragging rights at a cruise-in/parking lot show ain't worth squat. If you plan on actually taking your car down a drag strip, or plan on running it flat out, that's a whole different ball game.
 
#12 ·
You're right, muscle car fans usually aren't looking for all they can get out of their combos. They're just normal passenger cars, after all.
 
#16 ·
EO/IC. right for any 4-cycle engine with any cam. no need to re-invent the square wheel, beat your head against a nearby wall, go around wondering if it's right, re-do it several times, wake up at night wondering if you did it right, spew oil all over the car and the floor, arrange the proper angle of gravity, check the phase of the moon, consult the horoscope, etc, etc.

I wonder why so many guys try so hard to avoid doing it right. I've been posting the correct, works every time, method here since 1999. It never changes. Also nice because since it has you adjusting each valve near the center of the heel of the lobe it doesn't matter if your off a few degrees on the rotation.
 
#17 ·
I like this method;



Intake Valve Adjustment: ENGINE OFF!
with #1 cylinder Intake Valve at full valve lift .... Adjust #6 Intake Valve
with #8 cylinder Intake Valve at full valve lift .... Adjust #5 Intake Valve
with #4 cylinder Intake Valve at full valve lift .... Adjust #7 Intake Valve
with #3 cylinder Intake Valve at full valve lift .... Adjust #2 Intake Valve
with #6 cylinder Intake Valve at full valve lift .... Adjust #1 Intake Valve
with #5 cylinder Intake Valve at full valve lift .... Adjust #8 Intake Valve
with #7 cylinder Intake Valve at full valve lift .... Adjust #4 Intake Valve
with #2 cylinder Intake Valve at full valve lift .... Adjust #3 Intake Valve

Exhaust Valve Adjustment: ENGINE OFF!

You will notice that this is the same procedure and sequence as the intake valves listed above. Only now you are adjusting ONLY the exhaust valves the same way.
with #1 cylinder Exhaust Valve at full valve lift .... Adjust #6 Exhaust Valve
with #8 cylinder Exhaust Valve at full valve lift .... Adjust #5 Exhaust Valve
with #4 cylinder Exhaust Valve at full valve lift .... Adjust #7 Exhaust Valve
with #3 cylinder Exhaust Valve at full valve lift .... Adjust #2 Exhaust Valve
with #6 cylinder Exhaust Valve at full valve lift .... Adjust #1 Exhaust Valve
with #5 cylinder Exhaust Valve at full valve lift .... Adjust #8 Exhaust Valve
with #7 cylinder Exhaust Valve at full valve lift .... Adjust #4 Exhaust Valve
with #2 cylinder Exhaust Valve at full valve lift .... Adjust #3 Exhaust Valve


How can it br incorrect?
 
#18 ·
Setting the valves
exhaust opening, adjust intake
intake closing, adjust exhaust

Spinning the pushrod with your fingers is just a way to find the zero lash point. Don't get hung up on this.

With Polylocks:
Back off all your polylocks at least two full turns. Back off the setscrew in each one at least two full turns. Turn the engine with balancer bolt or remote starter switch till #1 Exhaust just starts to open. Judge this by eye, you can see the the pushrod start to move up. Spin the Intake nut down to zero lash, confirm by rattling the pushrod up and down and spinning until the play goes out. Adjust the Intake to 3/4 turn preload. Run the setscrew down to lock, then give the nut another 1/16 turn to jam the setscrew firmly. Go to number 8, turn the engine 1/4 turn, see the #8 Exhaust pushrod start to move up, adjust the #8 Intake as on #1. Then turn the engine 1/4 turn, see the #4 Exhaust pushrod start to come up, adjust the #4 Intake as before. Go thru the firing order 1-8-4-3-6-5-7-2 one at a time. Back to #1, turn the engine till the #1 Intake valve goes to full open and starts to close, it will take like a full turn of the engine. adjust the #1 Exhaust like all the others. Turn the engine 1/4 turn, see the #8 Intake go to full open and start to close. adjust the #8 Exhaust as before. Give the engine 1/4 turn, see the #4 Intake go full open and start to close. Adjust the #4 Exhaust as before. go the rest of the way through the firing order as before. Sanity check: when done all the nuts should be about the same height, all the setscrews should be about the same depth. If any are way off do that valve again.
 
#19 ·
It may not be necessary to do the EO/IC (did I get it right that time?) but FFS it doesn't take any longer to do it that way and it IS more accurate.
 
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#21 ·
It can't be "more" accurate if its perfect doing it the old school way.

I always tried so hard to avoid doing it right that I would wear myself out and have to stop and rest before finishing. :)

But seriously, I never heard of the EO/IC method before learning it here on TC and I guess the author of the motor manuals I used evidently hadn't either but being a shade tree mechanic, I never have done a motor with a radical cam or solid lifters so it didn't matter.

I will admit, I've adjusted plenty of small block valves with the motor running using those clips or a valve cover with the center cut out.

I'm pretty much done now myself but if I'm ever supervising one of the younguns I'll be sure and teach them the "right way" (If I can remember)
 
#22 ·
I regret ever removing the bolt down rockers on my GT40 heads and installing something adjustable. Bolt and go was much easier. Went to 6200 as needed.

Otherwise the EO IO is the easiest to execute and most reliable. I tried some of the other methods, but you have to write stuff down, and they I spilled beer on the paper and had to start over.
 
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