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So I thought I was making progress...

Mark Barnes

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I fixed one simple problem today. While I was patting myself on the back, I created another one, just slightly worse.
Tried to reset the valves in the new 273. Thought I was dealing with typical solid lifter heat 'em up, gap them and fine tune if necessary. Wrong. Very wrong.
The previous owner had replaced the original cam with a hydraulic Comp Cams XE262H-10, and leftbthe Carter 2bbl. on it.
Figured I could tweak hydraulics as well as the next guy so put the socket on the first adjustment nut while it was idling, and proceeded to break it off before I could even turn it. Soo....
Any ideas on how it's ACTUALLY done before ruin a perfectly good motor?
 
For each cylinder: exhaust starts to open-adjust the intake, intake just finished closing-adjust the exhaust. Seeing how the lifters are filled with oil, loosen the adjuster until the pushrod will move up and down with your fingers. Then, slowly tighten adjuster until the pushrod play stops, and turn the adjuster an additional full turn. This will set the lifter preload.
 
Try this:

V A chart.jpeg
 
You don’t adjust hydraulic lifters while running, at least I’ve never done that. No matter what method, you need the lifter on the base circle of the cam. Get to zero load like mentioned, I typically only go 1/2 - 3/4 turn. Splitting hairs at that point but you shouldn’t be snapping anything.
 
If you have hydraulic lifters, does it make any noise? All the lifters are noisy?
Why do you think it needs adjustment?
 
If you have hydraulic lifters, does it make any noise? All the lifters are noisy?
Why do you think it needs adjustment?
Ran poorly, like a dead cylinder. I thought that the PO may have cranked down too hard on some of the adjusters. He didn't seem to have a lot of experience with engines, and after I was done it seemed to run/idle better.
Like I said earlier, I broke a nut on the first rocker, so maybe I should be asking what is the approved tool to use.... that nut seemed to break WAAAY too easy when I put a socket on it.
**That, and I didn't know he had changed the cam from solid to hydraulic.**
 
Last edited:
If it was running you probably added side load to the adjuster screw. The friction lock in the threads of 273 rockers is very low.
Doug
 
You don’t adjust hydraulic lifters while running, at least I’ve never done that. No matter what method, you need the lifter on the base circle of the cam. Get to zero load like mentioned, I typically only go 1/2 - 3/4 turn. Splitting hairs at that point but you shouldn’t be snapping anything.

Just cuz you've never done it doesn't mean much... Back when adjusting hydraulics was common it was done all the time...
And it's still the best method....

The adjuster probably was already cracked....... Personally on 273 rockers I replace the adjusters with the type tat have lock nuts... Run a tap through the rocker to clean the threads & remove the locking thread then install new adjusters & lock nuts...

Adjust them running, loosen till you hear the tick, slowly tighten till the tick goes away then add 1/2-3/4 turn of preload....

Trying to adjust a hydraulic with the engine off finding the true zero lash point can be problematic, as you are turning the adjustment the lifter is bleeding down... so its easy to wind up with to much preload & I've seen engines whee the person totally missed the hydraulic portion of the lifter & preloaded the lifter after it locked solid...

On solid cams I definitely prefer static adjustment but hydraulics running is better...
 
I'd love to see a video of someone adjusting rockers with the adjuster at the end of the rocker bouncing up and down with a wrench attached, oil flying all over. I call BS. Show us a video. No way I would ever adjust them running. Maybe a stud rocker on a Chevy. Even then its messy. During race season I adjust valves weekly. Simple procedure. First realize that your valve order is E I I E E I I E. Now get a push button switch and attach it to the yellow wire location at the starter solenoid. Attach the other end to battery plus. Start at the front on the left side and work your way back. When the intake starts to close set the exhaust. When the exhaust starts to open set the intake. A little one way or the other won't matter as far as where the open/close valve is. To adjust: Loosen the adjuster until you can spin the pushrod with your fingers easily. Tighten until you feel very slight resistance. You can go back and forth with the adjuster until you get a good feel for it. Then tighten 1/2 -3/4 turn. You will now have .020"-.030" preload. If your rockers gets swapped to a lock nut adjuster ( which I highly recommend) tighten the lock nut. I've done it so many times that I don't even go front to back. Just watch the rockers and find the next one opening or closing. Takes me less than 15 minutes start to finish.
Doug
 
I'd love to see a video of someone adjusting rockers with the adjuster at the end of the rocker bouncing up and down with a wrench attached, oil flying all over. I call BS. Show us a video. No way I would ever adjust them running. Maybe a stud rocker on a Chevy. Even then its messy. During race season I adjust valves weekly. Simple procedure. First realize that your valve order is E I I E E I I E. Now get a push button switch and attach it to the yellow wire location at the starter solenoid. Attach the other end to battery plus. Start at the front on the left side and work your way back. When the intake starts to close set the exhaust. When the exhaust starts to open set the intake. A little one way or the other won't matter as far as where the open/close valve is. To adjust: Loosen the adjuster until you can spin the pushrod with your fingers easily. Tighten until you feel very slight resistance. You can go back and forth with the adjuster until you get a good feel for it. Then tighten 1/2 -3/4 turn. You will now have .020"-.030" preload. If your rockers gets swapped to a lock nut adjuster ( which I highly recommend) tighten the lock nut. I've done it so many times that I don't even go front to back. Just watch the rockers and find the next one opening or closing. Takes me less than 15 minutes start to finish.
Doug

I agree with the watching the rockers opening & closing ramps, done it that way for 40 plus years on solids....

On Hydraulics I assure you it can be done running, they use to sell a tool just for it see photo...

Screen Shot 2020-04-03 at 11.24.19 AM.png


Yes stud mounted rockers are easier but adjusters on the arm aren't that hard once you have the technique down... You hold the wrench loosely to allow it to move some with the rocker....

I don't have anything needing a valve adjustment so a video ain't happening.. Even if I did have something needing adjustment I wouldn't know how to post a video.... But I know how to adjust valves.... LOL...
 
Gentlemen, especially dvw-
I started out on small block Chevy's...easy doing a hot, running adjustment. Obviously, the Chevy stud is centered in the rocker, so no real movement when doing the adjusting. Mopars, specifically this 273, WAAAY different. The adjustment happens out at the end of the rocker, where ALL the movement happens. Broke off a nut the first time I tried. Gotta be more careful with these!
 
Still no reason to do them running. Its a mess oil everywhere. Why on earth would anybody do it? And yes I've done it on Chevy's. Would never ever do it again. Its more time to clean up than its worth.
Doug
 
Just cuz you've never done it doesn't mean much... Back when adjusting hydraulics was common it was done all the time...
And it's still the best method....
.
Why is it the best method? School me please.

I’m always open to something new.
 
I'd love to see a video of someone adjusting rockers with the adjuster at the end of the rocker bouncing up and down with a wrench attached, oil flying all over. I call BS. Show us a video. No way I would ever adjust them running. Maybe a stud rocker on a Chevy. Even then its messy. During race season I adjust valves weekly. Simple procedure. First realize that your valve order is E I I E E I I E. Now get a push button switch and attach it to the yellow wire location at the starter solenoid. Attach the other end to battery plus. Start at the front on the left side and work your way back. When the intake starts to close set the exhaust. When the exhaust starts to open set the intake. A little one way or the other won't matter as far as where the open/close valve is. To adjust: Loosen the adjuster until you can spin the pushrod with your fingers easily. Tighten until you feel very slight resistance. You can go back and forth with the adjuster until you get a good feel for it. Then tighten 1/2 -3/4 turn. You will now have .020"-.030" preload. If your rockers gets swapped to a lock nut adjuster ( which I highly recommend) tighten the lock nut. I've done it so many times that I don't even go front to back. Just watch the rockers and find the next one opening or closing. Takes me less than 15 minutes start to finish.
Doug
Back in the "I was a Dodge dealer mechanic days" I only did slant six valve adjustment while running. Of course you could idle a SS down to 400 rpm. I wouldn't attempt a engine idling at 800-1000 rpm!
Mike
 
Why is it the best method? School me please.

I’m always open to something new.

Because you actually get feedback from the lifter, it's not based on feel and what you think/expect the lifter to do...

How many times have you ran the valves & still have a slight tick? That can't happen if your listening to the valve train as you make the adjustments.. And if it does chances are something else is wrong... Bad lifter, worn rocker or valve guide.. Etc.... And you know it before you put the valve covers back on... I agree running the valves doesn't take long, but sometimes getting the covers off & back on does take some time...

And I agree with 493 Mike, idling it down does make it easier..

Oh, you mentioned how messy it is, well there were lots of oil deflectors designed & sold back in the day... But since Mopars don't oil through the pushrod they tend not to be nearly as messy...
 
You mentioned 'someone else' had swapped cams...so before you dive in and start giving things a half or 3/4 of a turn or whatever preload you want, make sure you have regular hydraulic lifters in there and not the limited-travel or 'anti pump-up' style....these are made to run with very little preload and you can cause yourself a big headache if you set them as you would the standard-type lifters. Odds are they're standard, but.........? Normal ones have a thin wire retainer at the top, where the anti pump-ups use a beefier steel clip. Only takes a second to peek on there with a flashlight..
 
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