Jump to content

How much shaft wear is too much for basically stock 322?


Recommended Posts

^———. Do that.  Same crap shoot for me with an undocumented cam and wrong spec’d inner valve springs -averted a disaster - that’s why my approach was the two-step math first, then verify with measurements.  School of hard knocks no pun intended.

 

The spring bind would look like either an inner or outer or both valve springs compressed until all coils were touching and the spring essentially becomes a solid column, which will bend rods and crack rocker arms.  The spec is unique to each spring part number.  Typically one takes the lift of the lobe in inches multiplied by the rocker arm ratio (1.5 is 322 stock) to get the valve lift, subtracts that from installed height and compares that height to the spring bind spec and shoots for .060 of margin. See page 19 save me some typing:

 

http://www.engineprofessional.com/articles/EPQ215_18-38.pdf

 

After the “theory”  my preference was to instrument it and measure to make sure. There are probably more experienced folks that might have other approaches. You need either a solid lifter “slug” or a fully pumped up lifter to get the full lift off the camshaft for the measurement.

 

I don’t think that’s your problem or you’d have lots of broken parts but pay attention to the longer stems and .  My hunch agrees with the others you had some stuck parts or already bent parts or interchanged parts.  If everything is moving now, it’s math and the right consistent assembled length on all the assembled pushrods and lifters.  Pump up the lifters, put it together and slowly tighten the stands down checking the pushrods as they tighten.  There’s also a shoulder on that washer that is under the rocker stand bolt. Make sure that’s seated properly.  Watch that valves open for those lifters on the lobes as you evenly torque done the stands.  Little at a time and evenly.

 

There should not be any shims under the valve springs from stock.it’s a practice  I can’t seem think off the top of my head unless it’s to make up for seat wear - maybe someone can help with that if I’m gettin this wrong.  I tried to avoid those shims.

 

Regarding the cams ID, here are pictures of two examples from 1 refresh and 2 rebuild episodes, an aftermarket one based on the 401 slug from a vendor turned and reground for a 322 along with lobe lift measurements and markings, and then a stock 55 one.  If you’re able to get in and measure the base circle and the lobe lift you would get an idea if the assembly will bind or not that might be hard with it installed. I think it’s easier to just pump up a lifter and turn it over by hand with correct parts and observe the workings a number of times.  You clearly have an aftermarket cam.  


If you want to get fancy and do the degree the cam thing I’ll forward links that helped me figure out what I had vs type it.  Consider trying what Chris and Willie suggest first.

 

EE8A8D3D-CDA7-4E66-96A9-6D19B73226A5.jpeg.85c98e06bac83aed34077632869411fb.jpeg

 

A1D3752C-60B0-4953-AFDC-3535611110D7.jpeg.e5548c94074daaa5672cee532b789cb4.jpeg
 

Hope this helps 

 

Just looked back and appears some of your numbers match my aftermarket cam…go figure.

 

 

Edited by KAD36 (see edit history)
  • Thanks 1
Link to comment
Share on other sites

edit #2.  I misread your post. I thought the shims were under the valve springs. I do not recall a case why one would put brass shims under the valve rocker shaft stands. Visualizing the geometry it would seem those shims are trying to raise the rocker arms to  compensate for valve stems or pushrod lifter combinations that are too long.

 

 

Edited by KAD36 (see edit history)
  • Like 1
Link to comment
Share on other sites

KAD 36, what lifters and rods would be chosen for that aftermarket cam of yours?

 

The washers under the shaft bolts are mismatched on mine, a few weren't even there but I'll see if i can come up with something. I guess when install the rods, I'll leave the shims in there, see how it all works, then try without.

 

How would i pump up or preload the lifters?

Link to comment
Share on other sites

As discussed all new 56 lifters and pushrods bought from same vendor/brand.  You likely have the same cam blank and may need to check the profile for lift since that’s what we are concerned with.

 

Put lifter in a jar of oil and pump it with a pushrod until all the air is out and it holds pressure. This is not the best method as if the lifter is worn it can bleed down slowly without oil pressure when lifting a valve but you’ll get some general indication of interference and free motion or not.  A solid slug same dimensions as a lifter, or a disassembled spare lifter with some washers stacked in it so the plunger can’t compress along with some math and measurements are better. You’re looking for basic free movement and observing/measuring/calculating how far the valve springs compress so nothing jams up.  Take the plugs out so you aren’t fighting compression if you haven’t already it will help you feel for tension spots.  How sure you want to be is proportionate to how much you’re willing to dig in when the starting point is uncertain.

 

I read somewhere on using grade 8 washers under the heads of the rocker shaft stand bolt heads if the washers with the shoulders are missing but I can’t recall where or exactly why.  Had something to do about preventing damage to the stands when torquing down.  Shims under the stands sound like a shotgun compromise for something. Maybe someone on the team can help me out if either of the above are real or myths….

 

 

Edited by KAD36 (see edit history)
  • Like 1
Link to comment
Share on other sites

Have a hunch that the increased lift of the aftermarket cam may have been discovered on reassembly by the rebuilder.  The blanks are the same, hence the same B-57 number I’m guessing, but there is no telling what profile is on it.  In the example from the photos, the increased lobe lift of .0120” (.270” - .258) over stock translated to an additional .0180” of valve lift (.0120 x 1.5 rocker ratio) and that increased lift, or spring compression,  will work with stock Buick inner and outer valve springs because those springs can compress to less than an inch with margin before going solid.  If all new aftermarket springs were used in the rebuild, some brands specified for 322s will meet the close pressure in pounds of force, uninstalled height, and the seat diameter of the factory springs but will not be able to compress as far (meet the bind spec) as the factory springs and will go solid with higher lift cams and then bend pushrods rods/break rocker arms.  This was exactly my dilemma and fortunately some forum folks helped me work through the math and test process to discover that anomaly before light off or there would have been a real friggin mess.
 

The shims under the stands may have been added by the rebuilder to raise the rocker arm shaft as an attempt to compensate for that increased lift - sounds like a red flag.  Does anyone know if that’s a standard practice? How thick are these shims?  

 

My input would be take your longest stem intake and exhaust valve on each bank, make a solid 56 lifter, with a 56 pushrod, install and rotate the assembly moving that slug to each of the 4 positions.  That would be your 4 worst case test points - am advising checking both heads because we don’t know if the rebuilder decked or shaved the heads equally or what thickness head gaskets were used and it all adds up.  Don’t worry this is all very solvable.
 

Alternatively, adjustable pushrods are more expensive but perhaps that is the way to go if you don’t want to do the testing, measuring and math to see what you have. They can make up for all these variables and variations we don’t know.   My advice would be to still spin the assembly as discussed, use 56 lifters, and measure all the rods/lifters for consistency in length before install.  


Consider your first decision being keeping those shims we are assuming the rebuilder added or not.  That will establish the reference point for subsequent tests/measurements in preventing any more bent pushrods..
 

See this ain’t so bad after all 🤣

Edited by KAD36 (see edit history)
  • Thanks 1
Link to comment
Share on other sites

5 issues going at once with this thing, working on the brakes, the valve train issue and a freeze plug that’s welded itself to the head, you can definitely tell that I strayed from my own rule of buying something already running and driving good, ugh!!

 

Anyway, the brass shims seem to be cut from the same stock and have the same thickness, definitely not machine cut edges, they’re some home garage stuff, I have the 56 rods on the way but I’m thinking I should got adjustable, while I’m waiting on those, I decided to pull the weeping, rusty freeze plug, it’s not having ANY of it!! There’s no pulling anything out, I had to punch everything in so far and fish around the water jacket with a magnet, the outer lip is still there and has pretty much become part of the head, it’s kicking my backside for sure, I’ll have to grind or drill the edges out to hopefully end up with a clean surface to put in the replacement 

 

Anyone know the size to order?

01CCB007-BCEC-400A-AFC5-2ABF62D6AC26.jpeg

55E8FD2E-69BC-4AEC-894C-95A10DE1F0E6.jpeg

FE446531-EF25-4C86-9705-F1F5570C3E3B.jpeg

  • Like 3
Link to comment
Share on other sites

Not only is the shimming a modification but it is a potential road block to lubrication for the valves.   In the 55 Service manual it indicates oil for the rockers and valves comes up to the rocker arm shaft at the front bolt.  There should be an oversized bolt hole there which matches a similar hole in the rocker arm stand. That is the passage for oil to get to the rocker arm shaft, then the rocker arms, and from there to the valves.  If that oil supply was interrupted by the shims perhaps the whole problem of bent push rods is due to lack of rocker or valve lubrication?

 

 

 

  • Like 2
  • Thanks 1
Link to comment
Share on other sites

10 hours ago, avgwarhawk said:

The shimming under the cap stands is, well, baffling. 

Used to get around an interference problem somewhere in the valve train?  Discovered after reassembly and easiest way to reduce lift and fix maybe?  Judging from pictures…odd.

Link to comment
Share on other sites

1 hour ago, KAD36 said:

Used to get around an interference problem somewhere in the valve train?  Discovered after reassembly and easiest way to reduce lift and fix maybe?  Judging from pictures…odd.

 

I concur.  It was modification done on the fly.  Maybe the adjustable push rods is the best course of action or entire rebuild of the top end.     

  • Like 1
Link to comment
Share on other sites

I’m hoping that I just tweaked them when I first turned it over, either way can see what happens here when they come in and I can always fall back on adjustable I guess, not too stressed about it 

 

I tried to push on one of the lifters with a rod, I couldn’t get any movement, it felt solid as a rock, same with another randomly chosen example, how much give should these have as far as being able to depress by hand?

Link to comment
Share on other sites

48 minutes ago, jw1955buick said:

I’m hoping that I just tweaked them when I first turned it over, either way can see what happens here when they come in and I can always fall back on adjustable I guess, not too stressed about it 

 

I tried to push on one of the lifters with a rod, I couldn’t get any movement, it felt solid as a rock, same with another randomly chosen example, how much give should these have as far as being able to depress by hand?

 

The lifters are tough to push in. I tried to prime mine(new).   Yeah, no go.  I put them in a oil bath. There is a small hole in the side where air came out and oil went in.   I stuffed them in and let the oil pump do the rest upon starting.  

Link to comment
Share on other sites

Hmm, pumped up a lifter best I could, got a few air bubbles to come out, rods and "up" lifters measure right at 10, max height of valve tips from the valve cover lip averaged 1.49 but one or two were as high as 1.52

 

I have at least seven straight rods so I installed those on the right bank, removed the shims and installed the shaft assembly, this time installing just the seven that were low down towards the base circle of the cam, everything went smooth, turned it all over and it all looked great, seemed to rotate perfectly, watched springs for binding and found nothing even close, measured one valve tip at full compress and it measured 1.26 from valve cover lip (pictured) even fully compressed, you could get a screw driver in the outer spring and wiggle it a little, my next test will be to install the shaft assembly on lifters that are at the top of the lobe, see if I have to crunch down the rocker assembly like before then observe. I think what's most likely taking into account my skill level is that I messed something up, either bending them upon start up or when I installed the new shafts the first time, but then the mystery of the shims still remains.

 

I feel better knowing the adjustable push rods can install short, then be run on out to length, a little progress.

IMG_3795.jpg

IMG_3798.jpg

IMG_3799.jpg

Link to comment
Share on other sites

Sounds pretty good.  One other thing came to mind.  If you can peek in and make sure when the spring is compressed that the bottom of the top spring retainer does not hit the top of the valve guide - since we don’t know the depth of where the machinist set the guides in the head.  Just another place with potential for interference.

 

Confirm you checked inner and outer springs?

Link to comment
Share on other sites

I will Ken, after a bite and a little football, thanks for you and everyone else's input here, there's no way I would've ever known what to look for, can't wait to get this thing on the road

 

Turning the engine over, I noticed my balancer bolt came loose, didn't expect that, what's the best way to tighten that thing in the car with everything attached?

Link to comment
Share on other sites

You can use a pry bar or big flat-bladed screwdriver in one of the flexplate teeth (and wedged against the block, carefully) to hold the engine while you torque the balancer.  You'll obviously have to remove the inspection plate if it's still attached.  

Edited by Aaron65 (see edit history)
  • Thanks 2
Link to comment
Share on other sites

2 hours ago, jw1955buick said:

I will Ken, after a bite and a little football, thanks for you and everyone else's input here, there's no way I would've ever known what to look for, can't wait to get this thing on the road

 

Turning the engine over, I noticed my balancer bolt came loose, didn't expect that, what's the best way to tighten that thing in the car with everything attached?

 

You spun the engine counter clockwise by hand/ratchet and the crank bolt cam loose?  Sheesh. From my understanding the crank bolt for the balancer is set at 200 foot pounds. Anyone, correct me if I'm wrong here.  This rebuild by the local fix it guy must have drove Chevy. Same guy apparently rebuilt mine before I owned it. Plethora of issues with the rebuild on my 54.  Anyway, block a tooth on the flywheel gear with a flat head screwdriver. 

  • Like 1
Link to comment
Share on other sites

Thanks fellas, I'll get to that bolt tomorrow, so I checked all the inner and outer springs on both banks, it all looks great, seems to be plenty of space, wasn't able to really see the guides through both of those coils, tried to wedge a screwdriver in there and peak but I couldn't make anything out, I'm amazed at how good everything looks with all the nonsense going on. Monday i'll order the rods and then we'll see.

  • Like 1
Link to comment
Share on other sites

  • 3 weeks later...

Success! got '56 rods, installed, tuned it over many many many times by hand, didn't use those brass shims either, it all works, runs really great now, decent lope to the cam but idles pretty good, like most, it smooths out with additional rpm

 

As i was fixing a freeze plug issue, i thought it was a good time to replace the water pump. The old one that was on there looked like it could be the original, the more I dig into this "rebuilt" engine, the more I'm disappointed with workmanship or complete lack of.....anyway, runs better than ever now which still makes me think that I bent these rods while trying to crank it over after dormancy, lesson learned.

  • Like 3
  • Thanks 1
Link to comment
Share on other sites

Thank goodness that got figured out. Congrats!  So no adjustable pushrods right? Think it was smart that you pulled out those shims.

Link to comment
Share on other sites

14 hours ago, jw1955buick said:

Success! got '56 rods, installed, tuned it over many many many times by hand, didn't use those brass shims either, it all works, runs really great now, decent lope to the cam but idles pretty good, like most, it smooths out with additional rpm

 

As i was fixing a freeze plug issue, i thought it was a good time to replace the water pump. The old one that was on there looked like it could be the original, the more I dig into this "rebuilt" engine, the more I'm disappointed with workmanship or complete lack of.....anyway, runs better than ever now which still makes me think that I bent these rods while trying to crank it over after dormancy, lesson learned.

 

 

COOL GROOVY!!!!  That is awesome to hear!!!  I suspected you had running gear for a 56.  The shims threw us all for a loop though.  Wonder the thoughts behind the shims. 

Edited by avgwarhawk (see edit history)
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...