Author Topic: 0 rocker arms BIG or small 0 ? differences?  (Read 26341 times)

lynnbilodeau

  • Member
  • ***
  • Posts: 395
    • View Profile
Re: 0 rocker arms BIG or small 0 ? differences?
« Reply #15 on: May 02, 2013, 03:09:20 PM »
the rockers with the triangle are they also high performance rocker arms ?
That is correct.   Chevy sold them over the counter for many years.
Have compared three different looking "O" sets (litte, big and sideways) with a "V" set side by side with calipers and micrometers, and can find no appreciable difference among any of the four.

Gary.  I always keep ball and rocker in sets.   But... I would not be afraid to use a set that had been mixed.  Just get them really clean, install, and reset your valve lash after initial run in and again in 500 miles (which you were going to do ANY WAY, right?)

zman1969

  • Member
  • ***
  • Posts: 153
    • View Profile
Re: 0 rocker arms BIG or small 0 ? differences?
« Reply #16 on: May 02, 2013, 03:31:31 PM »
Gary I would try to keep them matched up. on a side note the set i just got have groovedballs for better lubrication, all SB i have seen prior were not like this - OE or A/M? I can get some pics up later if needed I assume they are A/M 
Rich
69 RS/Z DZ302 Daytona bumble bee
69 T/A clone LS6/6sp
69 Nova SS 396

69Z28

  • Hero Member
  • *****
  • Posts: 928
  • 69 X33D80 Z28
    • View Profile
Re: 0 rocker arms BIG or small 0 ? differences?
« Reply #17 on: May 02, 2013, 03:34:20 PM »
Yes I was. I'm a fanatical solid lifter fan since I was able to sit behind a wheel and drive, especially four speed cars. I was 10 when I got to move my first big tracker and trailer truck for my dad and 12 when I was able to drive a 4 speed hotrod on the road and in traffic (my dad wasn't pleased with those guys who let me). Since then any slight ticking sound coming from the rocker covers, I was in there and still am.

the rockers with the triangle are they also high performance rocker arms ?
That is correct.   Chevy sold them over the counter for many years.
Have compared three different looking "O" sets (litte, big and sideways) with a "V" set side by side with calipers and micrometers, and can find no appreciable difference among any of the four.

Gary.  I always keep ball and rocker in sets.   But... I would not be afraid to use a set that had been mixed.  Just get them really clean, install, and reset your valve lash after initial run in and again in 500 miles (which you were going to do ANY WAY, right?)
GaryC

'UNRESTORED' 1969 Cortez Silver Z28 X33 D80

69Z28

  • Hero Member
  • *****
  • Posts: 928
  • 69 X33D80 Z28
    • View Profile
Re: 0 rocker arms BIG or small 0 ? differences?
« Reply #18 on: May 02, 2013, 03:40:52 PM »
I've seen both, but I don't think chevies had grooved ones installed, those were more aftermarket. Just like Lynn said, I have heard it was ok as long as there are no problems with the surface of the rocker socket and the ball face, this information coming from some really old engine builders I knew growing up in Atlanta too.


Gary I would try to keep them matched up. on a side note the set i just got have groovedballs for better lubrication, all SB i have seen prior were not like this - OE or A/M? I can get some pics up later if needed I assume they are A/M 
GaryC

'UNRESTORED' 1969 Cortez Silver Z28 X33 D80

69Z28-RS

  • Hero Member
  • *****
  • Posts: 5778
  • owner since 4-Apr-1976
    • View Profile
Re: 0 rocker arms BIG or small 0 ? differences?
« Reply #19 on: May 02, 2013, 05:43:45 PM »
Just out of curiosity, I have heard it's best to keep the same pivot ball to the same rocker. Are there any exceptions or is it a must to get new pivots? Mine are all mixed up in a box, all look fine with no blueing, cracks, galling or score marks. I'm using roller tip stamped steel 1.5's at the moment and probably will continue using them when I finally pull the 350 and install the 302, but what if I did go back to the 'O' rockers?
It's very easy to run the balls/rockers on a wire or string as you take them off an engine... you can even clean them that way  and they will come off in the correct order as well.. :)     I would suggest using a little molybdenum disulfide on the metal/metal wear surfaces on installation; especially with the mismatched ones..  it should help the two rubbing parts develop an 'affinity' for one another pretty quickly.. :)
I also keep lifters in order, when the come off a cam I'm going to reuse; just put them in a small box ordered in the correct fashion, and label the box for front and L/R side..  *(and moly works great on lifter/cam wear surfaces as well during breakin..)
09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette, '60 Corvette, '72 Corvette
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan

69Z28

  • Hero Member
  • *****
  • Posts: 928
  • 69 X33D80 Z28
    • View Profile
Re: 0 rocker arms BIG or small 0 ? differences?
« Reply #20 on: May 02, 2013, 06:11:35 PM »
Yes, lube and lube and lube and lube.
GaryC

'UNRESTORED' 1969 Cortez Silver Z28 X33 D80

67 RS Ragtop

  • Member
  • ***
  • Posts: 102
    • View Profile
Re: 0 rocker arms BIG or small 0 ? differences?
« Reply #21 on: May 02, 2013, 06:57:02 PM »
It's always best to keep mated running parts together, as they develop wear patterns at the mating surfaces, such as a flat tappett does at the cam lobe, (which should not be mixed up, if you intend to reuse).  In the case of the pivots for the rockers, it's note quite so important, as long as there are no signs of discoloring, scratches / scoring, which you can "catch with your fingernail". JMO

lynnbilodeau

  • Member
  • ***
  • Posts: 395
    • View Profile
Re: 0 rocker arms BIG or small 0 ? differences?
« Reply #22 on: May 02, 2013, 11:34:34 PM »
Agreed.  Best to keep the parts matched.  However, mismatching parts without excessive wear is no reason to discard them, in my humble opinon.

And yes, the grooved balls are aftermarket.   The old GM hipo catalogue even encourages them on high lift cam apps.

68camaroz28

  • Hero Member
  • *****
  • Posts: 2228
    • View Profile
Re: 0 rocker arms BIG or small 0 ? differences?
« Reply #23 on: May 02, 2013, 11:43:38 PM »
If rebuilding an engine I'd not use used rockers. Why take a chance?
Chick
68 Z/28 NOR 01B Orig motor/trans/rear
69 Z/28 NOR 07A Orig Block & GM Cross-ram/carbs
69 L34 Rest. Nova Father/Son Car
69 L78 Surv Nova Purch 4/69 31K miles
67 L89 Corv Tribute
68 Corv 427/400 Orig motor
07 Corv Z06
R 68Z build- http://www.camaros.net/forums/showthread.php?t=182584

z28z11

  • Hero Member
  • *****
  • Posts: 1853
    • View Profile
Re: 0 rocker arms BIG or small 0 ? differences?
« Reply #24 on: May 03, 2013, 04:23:28 AM »
If rebuilding an engine I'd not use used rockers. Why take a chance?

My original "O's" are still together after all these years, and I won't hesitate to use them again. I don't want to spend $600.00 on some NOS set from a speculator if I can keep from it. I rebuilt the engine in '75, and among the parts I changed in upper valvetrain were the springs, lash caps, keepers and retainers, but not the rockers. Kept all the original parts and ratholed them. I had a Sig Erson Hi Flow IIH stick, hydraulics and titanium retainers, double wound Erson springs. I'm going back all original from cam to upper train - I really missed soaking the splash aprons with oil and listening to solids sounding like a frantic Singer sewing machine. 20W50 Union 76 racing oil was pretty cheap in those days; I loved the purple color on the driveway after adjusting valves. Stock oil pump in the engine would push 80 psi on my Stewart Warner mechanical gauge at about 2500 rpm, and until I bought a set of Erson lash caps to fit over the oiling holes, would just about empty the pan of a quart or two from one side to the other. Had to work quick -

Regards,
Steve
1968 Z28 M21/U17 BRG/W 1967 Chevy ll Nova SS 
1969 Z28 X77/M20/VE3 LeMans/W
1969 L78 X66/N66 Cortez/BVT
1969 Z11 L48/M35/C60/C06  1949 3100 5wd 235/6

68camaroz28

  • Hero Member
  • *****
  • Posts: 2228
    • View Profile
Re: 0 rocker arms BIG or small 0 ? differences?
« Reply #25 on: May 03, 2013, 10:38:04 AM »
If rebuilding an engine I'd not use used rockers. Why take a chance?

My original "O's" are still together after all these years, and I won't hesitate to use them again. I don't want to spend $600.00 on some NOS set from a speculator if I can keep from it. I rebuilt the engine in '75, and among the parts I changed in upper valvetrain were the springs, lash caps, keepers and retainers, but not the rockers. Kept all the original parts and ratholed them. I had a Sig Erson Hi Flow IIH stick, hydraulics and titanium retainers, double wound Erson springs. I'm going back all original from cam to upper train - I really missed soaking the splash aprons with oil and listening to solids sounding like a frantic Singer sewing machine. 20W50 Union 76 racing oil was pretty cheap in those days; I loved the purple color on the driveway after adjusting valves. Stock oil pump in the engine would push 80 psi on my Stewart Warner mechanical gauge at about 2500 rpm, and until I bought a set of Erson lash caps to fit over the oiling holes, would just about empty the pan of a quart or two from one side to the other. Had to work quick -

Regards,
Steve
I agree about not paying the $600 for NOS ones but why use them?  Are most of using a NOS cam (crazy $), bearings, lifters (another crazy $), valves, etc.? I'd be surprised to note any reputable engine builder that would want to use worn rockers but I've been wrong before. :) Geometry is key! 
Chick
68 Z/28 NOR 01B Orig motor/trans/rear
69 Z/28 NOR 07A Orig Block & GM Cross-ram/carbs
69 L34 Rest. Nova Father/Son Car
69 L78 Surv Nova Purch 4/69 31K miles
67 L89 Corv Tribute
68 Corv 427/400 Orig motor
07 Corv Z06
R 68Z build- http://www.camaros.net/forums/showthread.php?t=182584

jdv69z

  • Hero Member
  • *****
  • Posts: 1275
  • 69 RS Z/28 52E
    • View Profile
Re: 0 rocker arms BIG or small 0 ? differences?
« Reply #26 on: May 03, 2013, 12:57:44 PM »
I've actually read somewhere that those simple looking stock rockers are a heck of a fine piece of engineering, and that it's almost impossible to improve on them. Not sure, but I think maybe even Jerry M runs them on his stocker.
Jimmy V.

CNorton

  • Member
  • ***
  • Posts: 213
    • View Profile
Re: 0 rocker arms BIG or small 0 ? differences?
« Reply #27 on: May 03, 2013, 01:37:34 PM »
I, along with Jerry M. and several hundred other small block Chevrolet Stock Eliminator racers, have been using stamped steel rockers on 7000+ RPM Stockers since the late 1980s when rules regarding valve spring pressure and lobe duration were relaxed.  Within the past couple of years, NHRA bowed to pressures from racers and manufacturers to permit the substitution of stud-mounted roller rockers.  Over the course of time, I've sorted, literally, through bucketsful of used rockers looking for sets that bear the identical markings, I've mixed and matched rockers and pivot balls, I've used a die grinder to open the rocker arm slot to fit over 7/16" studs, I've routinely put 425# of open spring pressure on them and and generally violated most of the generally accepted common sense "rules of thumb" regarding valve train longevity.  At this point, I can safely say that the total number of parts failures related to rocker arm/pivot ball failures that I've experienced could be counted on one hand. 

Many years ago, cam grinders for our sport began to grind extra lift into camshafts to accommodate the issues of inherently inconsistent rocker ratios so, I'm positive that if I were to switch the rockers on my Stocker motor to rollers today, I'd have go go through the entire motor to reset the components for legal lift measurement as read off the retainer surface.  It has been my experience that the weakest link in GM's stock valve train stability has typically been the studs, not the rockers.  Big blocks and other engine-makes have not been so fortunate when it comes to valve train stability and it is my opinion that those are the racers who urged the liberalization of the rules to permit roller rockers. 

The above statements should not be interpreted as an indication that i have any knowledge about the details of Jerry's engine program.  Having said that, I've always known him to run legal motors so the fact that his Z28 twisted over 8000 using stamped steel rockers without major problems is merely a given.

Chuck

69Z28-RS

  • Hero Member
  • *****
  • Posts: 5778
  • owner since 4-Apr-1976
    • View Profile
Re: 0 rocker arms BIG or small 0 ? differences?
« Reply #28 on: May 03, 2013, 04:28:19 PM »
I've had 030 over 302's.. that would wind above 10,000 rpm with stock components... including stock rockers... :)
09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette, '60 Corvette, '72 Corvette
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan

lynnbilodeau

  • Member
  • ***
  • Posts: 395
    • View Profile
Re: 0 rocker arms BIG or small 0 ? differences?
« Reply #29 on: May 04, 2013, 04:13:11 PM »
If rebuilding an engine I'd not use used rockers. Why take a chance?

I have never considered it as taking a chance.  As noted, they are not the weak link.   I can't imagine any issue related to using a good used set of rockers and balls.  As long as there is no surface galling, there shouldn't be much to worry about.