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post #31 of 43 (permalink) Old Feb 29th, 20, 9:38 PM
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Re: Stamped rockers BBC

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At the risk of fueling the fire, I believe that a good stock rocker has its place in our chevelles, the issue of QUALITY being compromised for profits (overseas junk) is a very real risk, in the street motors of many of our members being driven less than 3000 or so miles a year, I doubt that there is very little advantage to rollers vs GOOD stock style factory rockers. I would suggest that in many instances they serve as talking/bragging points only and I'm sure that you are aware of the damage that the needle bearings in a roller rocker (or lifter) can do to a good motor if they self destruct. My point is that probably many of the roller rockers sold to members are not really needed based upon the milage they drive and relatively mild motors. My VortecPro 467 came thru with stock hi-po factory rockers and a hydraulic flat tappet cam, Mark recently indicated to me he no longer supplies flat tappet cams, "too risky". This tells me that quality has disappeared from this portion of the performance market, Rest assured, if I were to go a roller cam in my motor that I would be using roller rockers. PS...don't rule out "OLD SMOKE"S" wisdom just because it is dated, we all could have learned from his thinking,,,Chevy and Ford did.
I don't know where this fear of needle bearings being belched out of rollerized rocker arms comes from. Have a missed something here lately?

I've never heard of any stories on this board nor others of needle bearings spilling all over the internals of engines from roller rocker arms. However I have read stories from board members here of needle bearings being ejected out of roller lifters. Perhaps my knowledge of this possibilty is lacking. Has anyone here heard of this ocuring with roller rocker arms? Now as faras Mr. Yunik, here's something he also said in his book concerning connecting rods: "Use the longest damn rods you can fit in the engine." He insisted that a longer connecting rod will make more power. But the increased angularity of a longer rod places more side thrust on cylinder walls, which in theory at least, can cause a quicker wear rate on piston rings, and cylinder bores. So it isn't a good thing for longevity. It's a trade-off at best.

The increasing rod length approach banks on the so-called advantage of the longer rod creating more dwell time at TDC for the piston which in theory gives the combustion mixture more time to burn and develop cylinder pressures, and those increased pressures create more power. But how much extra power can really be obtained in a street car engine from just an increased connecting rod length alone? I'm very skeptical about it being any significant increase. Perhaps 10 HP? Just a wild guess though.

And then we cannot neglect to inquire as to what possible negative effects a decrease in piston pin height might bring, since the longer the rod, the shoter the piston height must be to allow more room for the connecting rod length increase.

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post #32 of 43 (permalink) Old Mar 1st, 20, 1:27 PM
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Re: Stamped rockers BBC

Perhaps you missed that Summit sells a kit to "update " GM LS rocker needle bearings or Isky sells a kit to replace some types of needle bearings with a bushing conversion, granted not as frequent as needle bearing failure in roller lifters but the issue exists as evident by these products being offered by the aftermarket.
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post #33 of 43 (permalink) Old Mar 2nd, 20, 8:50 AM
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Re: Stamped rockers BBC

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Originally Posted by vortec710 View Post
Perhaps you missed that Summit sells a kit to "update " GM LS rocker needle bearings or Isky sells a kit to replace some types of needle bearings with a bushing conversion, granted not as frequent as needle bearing failure in roller lifters but the issue exists as evident by these products being offered by the aftermarket.
Uhmmm, that's for roller LIFTERS, correct? It isn't kits for rolller ROCKER ARMS, is it? Like I said in my last post, I've often heard of incidents with roller LIFTERS, but never with roller rocker arms. I've heard of fears voiced of that happenin with roller rockers ams, but never heard of any claims of it actually occuring.

And there sure are at least as many engines built with roller rocker arms, as there are with roller lifters, (in fact, probably more).

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post #34 of 43 (permalink) Old Mar 2nd, 20, 9:45 AM
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Re: Stamped rockers BBC

FWIW,I was running low 12's at the track for many years with a mild 233/[email protected] .540 110 LSA hyd. roller in a 454 with GM long slot rockers. The engine is now garage art until I use it in something else.
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post #35 of 43 (permalink) Old Mar 2nd, 20, 9:51 AM
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Re: Stamped rockers BBC

my experience was highway driving killed the ball rockers, I guess time had something to do with it
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post #36 of 43 (permalink) Old Mar 2nd, 20, 10:20 AM
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Re: Stamped rockers BBC

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Originally Posted by BillyGman View Post
Uhmmm, that's for roller LIFTERS, correct? It isn't kits for rolller ROCKER ARMS, is it? Like I said in my last post, I've often heard of incidents with roller LIFTERS, but never with roller rocker arms. I've heard of fears voiced of that happenin with roller rockers ams, but never heard of any claims of it actually occuring.

And there sure are at least as many engines built with roller rocker arms, as there are with roller lifters, (in fact, probably more).
No, it's for the rockers. We (Straub) sell the trunnion kits or fully refurbished rockers. LS engines have a bad rep for spitting out factory rocker arm needle bearings.
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post #37 of 43 (permalink) Old Mar 2nd, 20, 10:45 AM
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Re: Stamped rockers BBC

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my experience was highway driving killed the ball rockers, I guess time had something to do with it
I have experienced this with aftermarket valve covers that did not have drippers. No problems with anything as long as you have the dripper valve covers.

I have run the H rockers with flat tappet cams with .638 lift and had no problem. Put a set of roller rockers on and run exactly the same et on a bracket engine.
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post #38 of 43 (permalink) Old Mar 2nd, 20, 12:26 PM
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Re: Stamped rockers BBC

Quote:
Originally Posted by vortec710 View Post
Perhaps you missed that Summit sells a kit to "update " GM LS rocker needle bearings or Isky sells a kit to replace some types of needle bearings with a bushing conversion, granted not as frequent as needle bearing failure in roller lifters but the issue exists as evident by these products being offered by the aftermarket.
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Originally Posted by steelcomp View Post
No, it's for the rockers. We (Straub) sell the trunnion kits or fully refurbished rockers. LS engines have a bad rep for spitting out factory rocker arm needle bearings.
Hmmm....I did NOT know that. Thanks for pointing that out.

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Originally Posted by sleeper View Post
I have experienced this with aftermarket valve covers that did not have drippers. No problems with anything as long as you have the dripper valve covers.

I have run the H rockers with flat tappet cams with .638 lift and had no problem. Put a set of roller rockers on and run exactly the same et on a bracket engine.
I've never had those dripper V/Cers but I've heard them mentioned a number of times in the past. My guess is that they aren't very easy to find, (maybe an item that you would have to come across on a lucky day at a swap meet perhaps). I'm gonna do a search for them justout of curiousity. Thanks

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post #39 of 43 (permalink) Old Mar 2nd, 20, 1:05 PM
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Re: Stamped rockers BBC

FWIW: Factory Dripper Valve Covers: Factory used on 70 and later Z-28 Alum. valve covers, Corvettes with magnesium valve covers (SBC), on all (?) Sp/Hi/Perf. BBC chrome covers (solid lifters/alum. HOLLEY intakes, don't believe they came on any Q-jet motors), I also came across a nice set of BBC black crinkle finish alum. late model BBC truck covers with drippers at a swap meet ($20.00/pr) and some, or all BBC crate motors with a black crinkle paint finish. At swap meets all you have to do is flip the cover over to check for the drippers and choose which ones you gotta have. The late BBC covers may use a different type of valve cover gasket that is recessed into the cover, Fel-Pro# VR50388R. The 66 and later dripper covers for a BBC are currently being reproduced, prices vary. There may be other applications which used dripper covers, I'm sure our other members will keep us up to date.
PS...I don't some of BBC alum. covers will clear all roller rocker arm set ups without you using a spacer or in some cases a double gasket, some do, some don't.
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post #40 of 43 (permalink) Old Mar 2nd, 20, 10:38 PM
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Re: Stamped rockers BBC

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Originally Posted by vortec710 View Post
FWIW: Factory Dripper Valve Covers: Factory used on 70 and later Z-28 Alum. valve covers, Corvettes with magnesium valve covers (SBC), on all (?) Sp/Hi/Perf. BBC chrome covers (solid lifters/alum. HOLLEY intakes, don't believe they came on any Q-jet motors), I also came across a nice set of BBC black crinkle finish alum. late model BBC truck covers with drippers at a swap meet ($20.00/pr) and some, or all BBC crate motors with a black crinkle paint finish. At swap meets all you have to do is flip the cover over to check for the drippers and choose which ones you gotta have. The late BBC covers may use a different type of valve cover gasket that is recessed into the cover, Fel-Pro# VR50388R. The 66 and later dripper covers for a BBC are currently being reproduced, prices vary. There may be other applications which used dripper covers, I'm sure our other members will keep us up to date.
PS...I don't some of BBC alum. covers will clear all roller rocker arm set ups without you using a spacer or in some cases a double gasket, some do, some don't.
Thanks Lance. And I hear ya about the factory valve covers not having enough height for some roller rocker arm poly lock nuts. Good info.

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post #41 of 43 (permalink) Old Mar 3rd, 20, 7:15 AM
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Re: Stamped rockers BBC

illustrates my point-needle bearing rockers don't need the extra attention, I used used both aftermarket alu covers and stock I guess corvette chrome covers with drippers they came from a Chevy dealer parts counter, the dripper covers reduced the problem but didn't fix it
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post #42 of 43 (permalink) Old Mar 4th, 20, 12:30 AM
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Re: Stamped rockers BBC

I think that the bottom line here is that it's all about trade-offs. Lots of guys here seem to be concerned about needle bearings being a potential problem. OK, but the alternative is the extra heat and wear with a stamped steel rocker sliding back and forth against it's mating parts surfaces, and whether or not the slot in the stamped steel rocker is long enough, isn't the only potential issue with a stamped steel rocker arm in a hi-perf street application.

I say that because just because the slots can handle up to a .600" lift doesn't mean that all problem potentials are solved. The greater the lift created by the camshafts used, the longer the travel of the rocker arm sweep is. And the longer the sweep or travel of the rocker is, the more friction per RPM occurs. Kind of in the same manner the greater piston speed of the longer stroke engine creates more wear on the piston rings and cylinder walls per RPM. In that same manner, the larger camshaft lift creates more wear of the stamped steel rocker. This can also be said of a flat tappet cam vs. a roller cam.

The flat tappet lifter doesn't have any needle bearings to be concerned about. However the trade-off is that along with being needle bearing free, the flat tappet lifter carries with it a different type of wear poteintal since there's more friction going on from the sliding action of the cam lobe against the lifter just like the friction between the stamped steel rocker and the valve tips and the rocker studs. My point is that there are no free lunches in this game. It's always about trade-offs. So pick your poison gentlemen. The choices are yours.

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post #43 of 43 (permalink) Old Mar 4th, 20, 9:27 AM
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Re: Stamped rockers BBC

I agree duration plays a role not just lift, typical street performance cam will have at least 30 more degrees at .050 than a grocery getter cam and the seat duration increase is even more
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