when do you need rocker stud girdles?

[Steelrat]

Are rocker stud girdles for high rpm, high spring rate builds or? I do not have them.
My build:
Engine is a .040 over 400 small block
Block is decked and drilled for steam holes
Scat 9000 crank
Scat forged 4130 5.700" Rods, ARP 8740 Bolts
Mahle pistons 10:44 compression
Competition valve train
Crane gold full roller rockers
Competition Hyd Cam 284xe.
AFR 210 Fully CNC Heads.
Hogged out RPM Air Gap Manifold
Custom 950 Pro Series Carb
3:77 gears
Dyno'd at 488 HP 504 TQ @ motor

[Yoda4561]

Yes, they maintain valvetrain stability and accuracy at high RPM's. Pretty much a waste of money unless you spin past 6500 RPM on a regular basis, or if you're doing extended high RPM stuff like circle track.

[Johnny Blaze]

As said, for high rpm an heavy valvetrains like bbc.

[Lowend]

IMHO - any time you go to a solid roller cam.
Stud Girdles are cheap insurance

[Fast01]

Definately with a solid roller. Spring pressures get real high with some of the modern grinds.

[jfaria78]

As said, for high rpm an heavy valvetrains like bbc.

Don't agree with you there, a BBC valve train is no heavier than a small blocks, valves are bigger, but rockers and springs/retainers are relatively the same size. I would think a heavy valve train is a 426 hemi with rockers that are 4 inches long and two SS horizontal bars...

[jfaria78]

Are rocker stud girdles for high rpm, high spring rate builds or? I do not have them.
My build:
Engine is a .040 over 400 small block
Block is decked and drilled for steam holes
Scat 9000 crank
Scat forged 4130 5.700" Rods, ARP 8740 Bolts
Mahle pistons 10:44 compression
Competition valve train
Crane gold full roller rockers
Competition Hyd Cam 284xe.
AFR 210 Fully CNC Heads.
Hogged out RPM Air Gap Manifold
Custom 950 Pro Series Carb
3:77 gears
Dyno'd at 488 HP 504 TQ @ motor

IMHO I would go with Shaft rockers before I went with stud girdles. I believe stud girdles transfer harmonic vibrations to all your rockers instead of just one. They also do nothing to make your rocker arm go straight up and down like a shaft rocker does. At high RPM's it is really recommended you have a shaft rocker not a stud mounted rocker arm. Look to NASCAR or a Pro Stock car for proof. Besides you can buy Chinese shaft rockers for 200 bucks from Larry's Track products he is out of Montebello CA.

James

[wmhjr]

Not everyone is building a chevy. In pontiac motors, roller cams with a good amount of lift make stud girdles cheap insurance. Lifter bore braces aren't a bad idea either. If it was just spinning past 6500 that called for them you'd never see a pontiac standard block with them. I dynoed my current motor to 6500 but will never spin past it (and will really never push it past 6000).

[Vegas69]

Don't agree with you there, a BBC valve train is no heavier than a small blocks, valves are bigger, but rockers and springs/retainers are relatively the same size. I would think a heavy valve train is a 426 hemi with rockers that are 4 inches long and two SS horizontal bars...

I disagree with you. Larger valves, larger lifters, longer pushrods, equal more weight. A stud girdle is cheap insurance with high spring pressures and high rpm. That being said, you must make sure you buy the correct girdle for your heads. They can be more trouble than they're worth. I'm running dart girdles on my dart heads. My engine builder has experience with them and knows they work and don't change adjusmtents. You may not be so lucky on factory heads or an odd ball. A hydraulic roller shouldn't need it. If you plan to turn it tight that much, you should have a solid roller anyway. I also wouldn't use chinese shaft mounted rockers. That's asking for trouble.

[H2Ogbodies]

Okay for one thing if you are seriously that concerned about valvetrain harmonics, it's time to invest in a belt drive instaed of a chain-there's most of your harmonics out the window right there. And yes not all engines will readily accept shaft rocker mounts. As spring pressures go up, the rocker stud (screw-in) is fighting being bent back and forth as the pushrod moves the rocker through it's arc motion acccuating the valve. What this does is create various pressures on the valve stem tip and can have an affect on precisely how far off-center the valve is opening or closing-not paying atttention to this leads to bent valves, tore up valve seats, etc. And, springs tend to build a lot of heat from the stress of going through these high RPM motions and not securing them as solid as possible only magnifies the problem. This then can affect timing. Stud girldes ensure accurate opening/closing of the valves and a belt drive will cure 90% of your harmonics. And with my experience in manufacturing, why anybody would want to take a chance on Chinese parts (espescially valvetrain) is beyond me...anybody have a clue as to how they gauge quality control and introduce inferior filler metals for cheaper production costs...? I do, don't even get me started on that...lol.

[jfaria78]

I agree that is why I have both jesel belt drive and shaft rockers on my car and I would not think of running anything else. All the racecars I work on have very similiar items (different manufacture's and or part numbers)as well. That's how I roll!

James

[jfaria78]

I disagree with you. Larger valves, larger lifters, longer pushrods, equal more weight. A stud girdle is cheap insurance with high spring pressures and high rpm. That being said, you must make sure you buy the correct girdle for your heads. They can be more trouble than they're worth. I'm running dart girdles on my dart heads. My engine builder has experience with them and knows they work and don't change adjusmtents. You may not be so lucky on factory heads or an odd ball. A hydraulic roller shouldn't need it. If you plan to turn it tight that much, you should have a solid roller anyway. I also wouldn't use chinese shaft mounted rockers. That's asking for trouble.

Well, add up all that suff, (I have) and it is less than 1 pound in difference with all stock items. Then take into account that any decent aftermarket head as undercut valves, different valve stem height and width, different retainers and locks,push rods are usually made of chrome moly or for the hardcore titanium so in theory. They end up being about the same weight as a stock SBC, but my comparison was not too a SBC, becuase I think a BBC has a fairly light valve train in comparison to a 426 hemi. Compared to a sprint car SBC even a hard core BBC race engine the valve train is heavy.

Maybe it is a personal preference but I would not run girdles, that's just me. Shaft rockers are a superior design.

I won't argue about stuff made in china, but for the price they are cheap and from what I hear are very reliable with engines that make power south of 500hp.

[wmhjr]

Maybe it is a personal preference but I would not run girdles, that's just me. Shaft rockers are a superior design.

I won't argue about stuff made in china, but for the price they are cheap and from what I hear are very reliable with engines that make power south of 500hp.

You ever build anything other than chevies? How about you find me a good set of shaft rockers that'll mount to KRE aluminum heads for a Pontiac standard block. Or maybe a buick nailhead.

If my current build were a chevy, I'd probably have gone to shaft rockers. It isn't, so I couldn't. The only shaft setup I'm aware of for ponchos is for E-Heads - and I didn't want Edelbrocks. Or KRE Hi-Ports. Stud Girdles definitely have their uses and applications.

BTW, for power "south of 500hp" why are we even discussing this? If we're talking shaft rockers or stud girdles, we're about the 500hp mark.

[Steelrat]

got some good discussion going there. Thanks for the feedback

Shaun

[H2Ogbodies]

Well, back to your original post, imo with a hydraulic cam, you don't need a stud girdle set, even if you are running a chain. Now, geardrivers (ugh) are the worst as far as harmonic vibrations and belt drives are the best for damping or more accurately, ''absorbing" it. With the Crane Gold Race rockers, you have one of the best rockers in the industry so you are good. You aren't in the neigborhood yet but there is thought that should be given to spring pressure at the highest point of cam lobe lift and that is where the spring (at the speeds we are talking about here) open and then slams the valve shut as the pushrod/lifter descends down the ramp of the lobe. In an ideal world this is a gradual process but in reality it is a violent affair and at that point seat pressure exceeding 300 psi can really beat up the valve seats in the head. Fancy 4 or 5 angle valves are great for flow but will wear out even faster than a standard 2 angle valve if it is fighting high spring pressures. Roller cams have much more gradual ramp profiles so the springs can handle a more aggressive lobe lift but again, extreme spring seat pressure wreaks havoc on the valve seats. CompCams beehive springs are a progressive style wherein they have relatively light spring pressure and they gradually increase seat pressure as the valve opens and gradually releases this pressure as the valve closes-this is less chaotic on the valve seats since they won't "bounce" as much when the valve closes. So even the valves slamming shut create harmonics...extreme cam profiles require high tension springs to maintain control of the valves-too weak a spring and when the valve closes, it bounces excessively and if you ever hit "valve float", you effectively have caused the spring to lose control of the valve-either the spring was too weak or you way over revved it-either way, you compromise the strength of the spring and it should be replaced since valve float can now occur sooner in your RPM range. I'm just illustrating how every part of the valvetrain contributes to harmonics and if you want to maximize your engine, try swapping to a bee-hive spring with the same spring tension rate as required for your cam profile. Keeping your springs cool will help them stay alive longer-I build integrated overhead oiling systems using pressurized oil from the block through SS tubes that extend into the valve covers, then small holes over each spring deliver cool oil right over the springs. The vibrations the springs have to endure is what builds heat so any attempt to cool them helps. Anyway, just think about how the entire valvetrain moves and wherever you see movement, try to find ways to make it more "effortless" and you'll reduce harmonics.