rocker shaft shims

[rt green]

they still sell those?     take some of the preload off?

[c00nhunterjoe]

i beleive mancini stocks them. why do you need to remove preload? sounds like you may have pushrod length issues. simply adding or removing a bunch of shims has a possibilty of geometry issues depending on your application

[rt green]

stock rocker set up. back in the day, we were taught Chrysler put a pretty good amount of preload on to compensate for 100,000 miles of wear. direct connection instructed to shim the shafts up a little bit to let it rev quicker. and I was thinking with a little bit bigger cam, it wouldn't be a bad idea. thoughts?

[don duick]

I made my own using sheetmetal.I have had preload issues. When I installed stealth heads the pre load was way off. Making shims are frustrating I bought a set of crane adjustable pushrods from summit for $160

[oestermarken]

http://chucker54.stores.yahoo.net/rocshafshim.html

/Brian

[BSB67]

stock rocker set up. back in the day, we were taught Chrysler put a pretty good amount of preload on to compensate for 100,000 miles of wear. direct connection instructed to shim the shafts up a little bit to let it rev quicker. and I was thinking with a little bit bigger cam, it wouldn't be a bad idea. thoughts?

There are advantages to having near zero perload, but I don't think it will rev quicker.  Not a bad idea, but if you really want to make a difference that might be seen on a dyno (likely not in the seat of the pants) you need to step up to adjustable rocker arms.  If you are not pushing the motor hard in the upper rpm range, it won't matter either.

[mopar0166]

stock rocker arm setup was so hard to find when I built my 440 last year , I just bought fancy ones.  My buddy who is a master mech  told me not to try and piece it all together.  the cost difference really wasn't much from the performance set I got and has performed well with eddy heads

[BSB67]

I made my own using sheetmetal.I have had preload issues. When I installed stealth heads the pre load was way off. Making shims are frustrating I bought a set of crane adjustable pushrods from summit for $160

Using flat stock (i.e. not tapered) for shims can cause the cast pedestal to crack and break off.  Then you are having a bad day.

[don duick]

I made my own using sheetmetal.I have had preload issues. When I installed stealth heads the pre load was way off. Making shims are frustrating I bought a set of crane adjustable pushrods from summit for $160

Using flat stock (i.e. not tapered) for shims can cause the cast pedestal to crack and break off.  Then you are having a bad day.

wow did not know that. Thanks for the information I would hate to see somebody doing damage because of my bad advice.

[don duick]

I have had bad luck with pump up on  2 sets of comp cam lifters and had to set them with zero preload. They are also quiet on cold startup and run ok. Now I know someone else with same motor 440 and same cam and lifters he has his set to 20 thou pre load and has lifter noise. Go figure 

[b5blue]

Shims are used to lift rocker shaft to correct valve train geometry from shaving heads, IE over angling the nose of the rocker.  I got a nice set off eBay for 18.00. 

[BSB67]

Shims are used to lift rocker shaft to correct valve train geometry from shaving heads, IE over angling the nose of the rocker.  I got a nice set off eBay for 18.00. 

Shaving the heads does not change rocker geometry.

[b5blue]

  As the heads are shaved the rocker shafts lower the same amount. Unless you compensate the stock push rods sit deeper and deeper in the hydr. lifter the same amount. ( I'm paraphrasing the Mopar B/RB Performance Book.)    Even with a solid lifter and adjustable rockers you do not want to lower the adjusters very much, it moves the push rod/rocker fulcrum point down and at full lift it over-angles. Hence one of the many aspects to valve train geometry that can be changed during even a standard rebuild much less an extensive build where the block is decked and the heads are cut also. Just like cutting the valves and valve seats will raise the valve stem's top higher. The factory tolerance can go all out the window as factors change from new parts.

[BSB67]

 As the heads are shaved the rocker shafts lower the same amount. Unless you compensate the stock push rods sit deeper and deeper in the hydr. lifter the same amount. ( I'm paraphrasing the Mopar B/RB Performance Book.)    Even with a solid lifter and adjustable rockers you do not want to lower the adjusters very much, it moves the push rod/rocker fulcrum point down and at full lift it over-angles. Hence one of the many aspects to valve train geometry that can be changed during even a standard rebuild much less an extensive build where the block is decked and the heads are cut also. Just like cutting the valves and valve seats will raise the valve stem's top higher. The factory tolerance can go all out the window as factors change from new parts.

I understand that you are very proud of what you have read, but shaving the heads does not change the rocker geometry.  It is not an opinion, it is simple, well, geometry.  The key relationships that define rocker geometry are not affected by milling the heads.  The valve job obviously will if you don't grind the valve tip.

If you mill the heads you will change the plunger depth of the lifter, nothing more.  The only correct solution for compensating for the head milling is a shorter pushrod, if it matters to you, or the lifter is bottoming out.

[rt green]

makes sense. thank you.

[fy469rtse]

I agree with BSB67,
i use shims to correct the travel pattern of my roller tip to valve stem , geometry

[Challenger340]

I have had bad luck with pump up on  2 sets of comp cam lifters and had to set them with zero preload. They are also quiet on cold startup and run ok. Now I know someone else with same motor 440 and same cam and lifters he has his set to 20 thou pre load and has lifter noise. Go figure 

Comp don't make Lifters, they just re-box whatever is out there that they can buy ? and typically on low numerical applications like BB mopars.... it is the cheapest crap they can find ! Offshore ? whatever ?... who cares ?          Same with Lunati and many others.
try here;
http://www.dodgecharger.com/forum/index.php/topic,95605.0.html
Works for me every time I've had a problem, with one caveat.... I dis-assemble all lifters first to remove the test fluid present as shipped, which can be very slow to bleed out during operation, if just installed ootb.

[don duick]

    

[b5blue]

 As the heads are shaved the rocker shafts lower the same amount. Unless you compensate the stock push rods sit deeper and deeper in the hydr. lifter the same amount. ( I'm paraphrasing the Mopar B/RB Performance Book.)    Even with a solid lifter and adjustable rockers you do not want to lower the adjusters very much, it moves the push rod/rocker fulcrum point down and at full lift it over-angles. Hence one of the many aspects to valve train geometry that can be changed during even a standard rebuild much less an extensive build where the block is decked and the heads are cut also. Just like cutting the valves and valve seats will raise the valve stem's top higher. The factory tolerance can go all out the window as factors change from new parts.

I understand that you are very proud of what you have read, but shaving the heads does not change the rocker geometry.  It is not an opinion, it is simple, well, geometry.  The key relationships that define rocker geometry are not affected by milling the heads.  The valve job obviously will if you don't grind the valve tip.

If you mill the heads you will change the plunger depth of the lifter, nothing more.  The only correct solution for compensating for the head milling is a shorter pushrod, if it matters to you, or the lifter is bottoming out.

Proud of what I read? I thought we were talking about VALVE TRAIN GEOMETRY not "rocker geometry". The book also states clearly grinding the tip of a valve stem is NOT an option, you cut through the hardened surface. The book was pretty clear on this and pointed out many racers over the years failed to realize the stacked tolerances fell out of factory perimeters. Mopar offered cut to fit push rods/shims/adjustable push rods and adjustable rockers with ball-cup push rods all for this reason. Your calling bunk on Chrysler not me.
Yes I read the book front to back before building my 440 and have had zero issues so I do chime in now and again just trying to help, not argue.       

[c00nhunterjoe]

  As the heads are shaved the rocker shafts lower the same amount. Unless you compensate the stock push rods sit deeper and deeper in the hydr. lifter the same amount. ( I'm paraphrasing the Mopar B/RB Performance Book.)    Even with a solid lifter and adjustable rockers you do not want to lower the adjusters very much, it moves the push rod/rocker fulcrum point down and at full lift it over-angles.

I beleive this is the main section of your post that bsb67 is referring to.
The 1st sentence is incorrect. milling the surface of the head WILL NOT change where the rocker shafts sit on the head.
On a hydraulic lifter, the angle of the rocker to pushrod will not change by milling the head. As your second sentence states, the pushrod will simply add a few thousandths more preload to the lifter. The angle does not change. The issue arises on a solid lifter where there is no preload. Milling the head still has no effect on the rockers but because the pushrod is now too long, if you compensate by using the adjuster instead of buying the correct length rods, you can run into pushrod to rocker over angling.
   All of this is extremely basic however. Depending on the brand rockers, installed height of the valves, and total cam lift, it all goes out the window and setting it all up becomes a magical peice of art to see function when finished correctly. You may look at the angle of the pushrod to rocker on your mild street motor and think its a little much, what do you think the angle looks like on a .800 lift cam? They can get pretty radical when you run tall valves to prevent coil bind in extreme lifts.

[b5blue]

they still sell those?     take some of the preload off?

I was just affirming his original post, shaved heads/decked blocks add lifter preload. Shims can reduce that without installing different push rods. Re-cut valves and valve seats can add more preload.
  Yes they still sell shims for that purpose, like I posted. The key point I read and agree with is a set of shims for 18.00 over the expense and hassle of other options like cut to fit push rods and adjustable rockers that still need fitted push rods saves huge money and time. When someone replies with a 600.00 fix to an 18.00 problem I'm inclined to chime in with my 2 cents worth. It's all good, we have passion for all Mopars! 

[c00nhunterjoe]

But if you go adding shims to the rocker shafts to try and save money on pushrods, you can throw tye rocker angles way off.

[BSB67]

 As the heads are shaved the rocker shafts lower the same amount. Unless you compensate the stock push rods sit deeper and deeper in the hydr. lifter the same amount. ( I'm paraphrasing the Mopar B/RB Performance Book.)    Even with a solid lifter and adjustable rockers you do not want to lower the adjusters very much, it moves the push rod/rocker fulcrum point down and at full lift it over-angles. Hence one of the many aspects to valve train geometry that can be changed during even a standard rebuild much less an extensive build where the block is decked and the heads are cut also. Just like cutting the valves and valve seats will raise the valve stem's top higher. The factory tolerance can go all out the window as factors change from new parts.

I understand that you are very proud of what you have read, but shaving the heads does not change the rocker geometry.  It is not an opinion, it is simple, well, geometry.  The key relationships that define rocker geometry are not affected by milling the heads.  The valve job obviously will if you don't grind the valve tip.

If you mill the heads you will change the plunger depth of the lifter, nothing more.  The only correct solution for compensating for the head milling is a shorter pushrod, if it matters to you, or the lifter is bottoming out.

Proud of what I read? I thought we were talking about VALVE TRAIN GEOMETRY not "rocker geometry". The book also states clearly grinding the tip of a valve stem is NOT an option, you cut through the hardened surface. The book was pretty clear on this and pointed out many racers over the years failed to realize the stacked tolerances fell out of factory perimeters. Mopar offered cut to fit push rods/shims/adjustable push rods and adjustable rockers with ball-cup push rods all for this reason. Your calling bunk on Chrysler not me.
Yes I read the book front to back before building my 440 and have had zero issues so I do chime in now and again just trying to help, not argue.      

Symantecs.

1) The depth of hardening, (some actually add harden tip or wafer) is different depending on the brand and make of the valves.  You can take .020 to .040" off of some valves without issue.  Decent head builders usually at least even them out, as after the grind they could be all over the place, along with all of the preloads.

2)Cutting the heads still does not change the valve train geometry.  Not one angle changes anywhere.

3)  When you shim the rocker shaft, you now have changed the geometry.  So if the original geometry was correct, which does not change because of a head milling, you just screwed it up with the shims.  So only changing the pushrod length will keep from altering the geometry.

[BSB67]

But if you go adding shims to the rocker shafts to try and save money on pushrods, you can throw tye rocker angles way off.

They will be effected.

[c00nhunterjoe]

But if you go adding shims to the rocker shafts to try and save money on pushrods, you can throw tye rocker angles way off.

They will be effected.

Yup, thats what i said.