273 rocker arm adjustment

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70dart65coronet

70dart65coronet

mopar or nocar
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Do you guys have a good method for adjusting 273 adjustable rocker arms?

I have them in my 340 in my 70 dart.

I notice when i warm up i can hear them, and i am also getting some real fine metal flakes in the oil filter. Once it warmed to noise goes away.

I was looking for some specs for a cold setting, and then i would check them hot.

There are so many different variations out there.

This is what i came up with, what do you think?

put engine at TDC #1 (at initial timing setting, which i think im set at 12 degrees) and check exhaust valve 1 3 4 8, intake valve 1 2 5 7

rotate one full rotation to get to TDC#6 and check 2 5 6 7 exhaust, 3 4 6 8 intake

The cam card say zero lash for both intake and exhaust, (it doesn't specificity hot or cold, so i assume hot)

Thanks
 
lash at 0 tells me its a hydro. If that's the case, give it .045 preload cold (one turn) after you tighten adjuster and feel any resistance on a spinning pushrod (0 lash). Adjustables are nice like that. Flakes in oil isn't good. If I were you, Id take those lifters out, remove their pistons (lifter) and flush them in solvent.
 
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Did you index the shafts correctly. How is the geometry?
 
This is old school. Warm the engine. Pull a valve cover. Start engine. Back off rocker till it makes noise. Tighten rocker until noise goes away. Go one quarter turn more. Lather rinse repeat.
 
A) Find out where the metal chips are coming from!
B) Don't do the adjustment hot. It does not matter with hydraulic lifters.
C) Don't worry about the ignition timing.
D) Use the Mopar chart for which valves to adjust, in what order.
E) "0" lash sounds wrong. Loosen the adjuster. Tighten just until the pushrod has no free play. Should go about 3/4 to 1 full turn tighter after that for the proper pre-load.

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Metal flakes in the oil!? It's noisy because your cam is going flat. The wear will just continue to run away. Change the cam and oil pump.
 
I can tell you this........."metal flakes" has nothing to do with valve lash
 
The excessive lash came from the wear of the cam and lifters, most likely.
 
I believe I have hydraulic lifters because I can push the rocker down on the push rod and get some movement, if I push hard I can get like .050 of feeler gauages between the rocker tip and valve tip.
 
im pretty sure these are hydraulic lifters, which doesnt really make sense, why would the PO put this big cam in here and the adjustable rocker arms out of 273 and then keep the hydraulic lifters. anyway, what is the best way to adjust these now?, i am seeing some differences between them. i dont believe that there is anything wrong with the cam. these are very small metal flakes. i found some wear in the rocker shafts and rockers, which i think has to do with this adjustment and combination of parts

https://wmwinklercompany.box.com/s/3xssj1kuk9ppx5syerttdca0wq29yid6

here is the video clip of the movement i am getting, which is why i think this is a hydraulic lifter

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Bodyperson said:
This is old school. Warm the engine. Pull a valve cover. Start engine. Back off rocker till it makes noise. Tighten rocker until noise goes away. Go one quarter turn more. Lather rinse repeat.
Click to expand...


There is no way you can set the clearance running with the adjuster off the pivot. You can do it on a Chevy because the adjuster doesn't move. Not on a Chrysler.
 
ok here is an update. i took off the rocker shaft assembly and inspected everything. i think i found the source of some of the metal. The inside radius underneath of the 273 rocker arm occasionally rubs on the valve spring and it is self clearancing. i found a page in one of my books that talks about this (PO didnt have this book apparently).

Also found one push rod bent and it has been hammered on so much that the ball socket came off the push rod. I checked all the push rods by putting them in my drill press and spinning them, i only found one straight one. so obviously there is an adjustment problem here.

I am going to order a new set of push rods and those rocker adjusters that come with a jam nut so the settings dont come loose and move the adjuster screw

I have hydraulic lifters, my cam card specifies that and it also specified 0 lash for both in/ex. So how do i set a zero lash with hydraulic lifters (when i slide the feeler gage in there it just compresses the hydraulic lifter)

The wear on the rocker arms and shafts, i believe i can polish that out and it will be fine, with the new parts i should be able to keep the lash set to where it should be and this would solve all the problems. I will also have to clearance out those rocker arms where they are rubbing on the valve springs.

Knotches...is there any rhyme or reason on their knoctching of the rocker shafts?

Front left top shaft has a punch style knotch. then the bottom rear of the shaft has a milling machine knotch.

Front rocker shaft has no knotches on the top, but has a milling machine knotch at the bottom front.

Thanks for your input and help

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I have heard guys clearancing the rockers for larger springs. In my opinion, I would park the adjustable setup and go hydraulics. Sounds like whomever put that together didnt do their homework. I would go over it thoroughly. Bent and broken pushrods, flakes, adjustables mixed with hydraulic, NOT a good recipe.
Good luck, hope its nothing too costly.
 
Yeah the shafts werent in correct either lol. Drivers side should only have one notch, at the front and pointing down. One notch per shaft. Passenger side pointing down but at the rear. DS front and down PS down and rear. One notch per shaft and it better be machined LOL
 
The marks on the rocker are small enough that you can take a paper roll and make a bit of clearance.

If you want to do it correctly, get ahold of Mike at B3 racing engines and have him hook you up with a geometry correction kit.

If the rockers hit the retainer/spring the geometry is off.
 
Also, cut a banana groove across the oil feed hole in the shafts. With hydraulic lifters there is always load on the rockers. They all should have groove but especially the hydraulics.
 
hmmm, interesting, so the notches are used for correct orientation is that so the oil holes line up with the rocker shafts? it looked like the holes were lining up properly. what happens when they run backwards, is that the galling i am seeing? (btw not sure why i started putting a k in front of notch, lol)

Another troubling thing i came across...should all the hydraulic lifters move when i press on them? some of them dont push down....(now that i have both rocker shafts off, i went to each push rod and push it down with my hand and some of them compress and some dont)

Yea the banana grooves, i could see that being helpfull, my ford 390 has them. are the machine shops setup to do those?

I am worried that my lifters are damaged now... i am not seeing the benefit to switching to 273 adjustable rocker arms, and now i am worried about the cam.
 
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Yes I believe the notches are to ensure proper orientation. Im still learning or at least trying to LOL. I know with my 67 273 it has adjustables as well.
I would think ALL of the lifters should push down/compress somewhat. Take a good bit of effort. Soak them all in oil BUT keep them in order so they go back in the right lifter bore! You cant mix lifters up once its run or kiss lobes goodbye. But that could be the case anyway.
70dart65coronet said:
hmmm, interesting, so the notches are used for correct orientation is that so the oil holes line up with the rocker shafts? it looked like the holes were lining up properly. what happens when they run backwards, is that the galling i am seeing? (btw not sure why i started putting a k in front of notch, lol)

Another troubling thing i came across...should all the hydraulic lifters move when i press on them? some of them dont push down....(now that i have both rocker shafts off, i went to each push rod and push it down with my hand and some of them compress and some dont)
Click to expand...
 
I wouldn't worry about the notch in the end of the rocker arm shaft. Seen enough of them notched incorrectly. What is important is that the oil holes face down, and down in the correct direction (more "vertical" than the hold-down bolts). See diagram below, which is from the factory service manual.
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And yes a hydraulic lifter's internal piston must freely move up/down.

Hydraulic lifter's preload needs to be adjusted via adjustable rocker arms, or by getting the exact length pushrods which provide the proper preload in your particular engine assembly. And unless it is original/production, they will almost always be a custom length pushrod. This problem is eliminated with the adjustable rocker arms.

Once you get some new pushrods, fix or replace your stuck or damaged lifters, and fix the rocker/spring clearance issues, follow my instructions, previously posted in this thread, to adjust the rocker arms.
 
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ok, so i didnt realize this until now, but you can get the lifters out through the head without taking the intake manifold off, i used a magnet and pulled one of the lifters that wasnt compressing, put it on the bench to confirm that it wasnt compressing, then i took it part, didnt see anything wrong with it, put it back together and now it compresses....not sure whats going on there. (was not looking forward to pulling the top of the engine off)

as far as the adjustment goes, am i looking to tighten adjuster so the push rod doesnt havent any free play but not compressing the lifter piston correct? this is a fine line, also i am still confused about the cam card saying 0 lash, how do you use a feeler gauge without compressing the lifter, also not sure about the pre load either.

Have you guys added the banana grooves before? how did you go about doing that?
 
Use the Mopar chart I posted before to set the correct rocker arms in the correct order. When the lifter is on the base circle of the cam lobe, loosen the rocker arm so that the pushrod is loose, then adjust the rocker arm tighter until just a slight drag can be felt while spinning the pushrod with your fingers, then tighten around 3/4 turn tighter. That's "0 lash" with a hydraulic lifter. Repeat 15 more times, after rotating the engine per the chart.
 
ok i will have to try it out when i get the new push rods and adjuster screws.

What do you guys think about those lifters locking up like that? its bizzare, take it apart, put it back to gether and then it works, that might have something to do with that one push rod that got bent and broken. also almost all the push rods are slightly bent...

I think my cam is fine, i looked at it through the lifter bores, im not really sure why i have to take the lifters apart and put them back together to get them working again. Odd thing about it, the lifter that had the bent broken push rod, was fully functioning.

this thing has very little hours on it, everything was new when it was built.
 
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