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Currently have a set of shaft mount rockers on the engine now (572 BBC) and am thinking about swapping to shaft mounts. Can somebody school me on the pros- cons(?) to help steer me in the right direction prior to spending the coin?!
Better stabilty, lash I'm guessing. Should be no power improvmment. Have no problems with lash moving around now. Stud wear where the rocker moves, but that will always be there. Anything else?

Thanks guys
 

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If it's in the budget I would always use shaft mounts. Better lash retention, better valve control, etc. You will get a whole lot of responses on this I would bet. By the time you buy a good set of stud mounts, studs and stud girdles you are quickly approaching the cost of a set of shaft rockers.
 

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Shaft mount is the way to go IMO. As mentioned a set of stud rockers and then a stud girdle is getting you close to the price range. Look into the T&Ds and if they are out of your budget, the Jesel Sportsmans.
 

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There is HP in keeping the valve train under control and stable, a shaft will help with that.
 

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I'm going to talk from a bracket racer standpoint. I didn't see any gains in power. My stud mounted valvetrain was very stable. For me, the benefit is easier maintenance. There is no stud girdles in the way, I can pull a rocker in 5 minutes. If you put that rocker on the base circle, you can remove and replace rockers and pretty much not even have to readjust them. So to just jump all over them for power increase promises, make sure you really need them. For a new build, I would definitely do it, because by the time you buy good rockers, studgirdle and studs, you could just as easily get a set of Jesel Sportsmans.
 

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why does it make it more stable. i have a girdle on my junk is it better then that??
 

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why does it make it more stable. i have a girdle on my junk is it better then that??

Girdle sits high in teh system, giving it leverage to move things, not to mention it links all of the tops together, so if one moves they all get affected. Girdles work great to a certain point, but for totaly controll a shaft mount system uses the common roker shaft as the binder giving much better and secluded controll. a shaft mount gives you more mounting points directly to a surface, not a tower to flex. I'm sure someone with more technical language can explain it better, but you get the idea.
 

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I agree with all of the above....and like bracketchev1221 I am speaking from a bracket racing point of view...to me (and I have Rocker and stud girdle set up right now) the best advantage is they virtually eliminate any flex or deflection in your valve train and this is the biggest advantage for me they retain your set lash a lot longer. Anytime I can eliminate worrying about something the better.....and with Shaft Mounts you just don't have to wonder if your lash has changed and you don't need to run your valves near as often. I am such a freak about keeping a eye on what is going on with my motor that I have the valve covers off after every weekend anyway sometimes at the end of each days racing (if I have made alot of passes) so I am in there checking my Valve springs and so forth anyway and it doesn't take that much longer.......BUT with that said if when we built this engine I had planned a bit more in the budget you can bet that I would have gone Shaft Mounts....and thats one of the up-grades I will make here in the near future when I do some other things.
So if you can find the coin to get them believe us it's money well spent .
RC
 

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I just changed out brand new Comp rockers, studs and a Dart girdle for all of the reasons above. For one, it allowed me to run short covers which fit my car better than the tall covers, two: better control from inertia phenomena condition at higher revs due to a more stable valve train with less deflection, and three; it's way easier to set the lash and keep it there one rocker at a time. No stud girdle to loosen, work around, and much easier to check the springs from a maintenance perspective. Crower stainless rockers for street use $1600 shipped vs studs, rockers and girdle at $800-$900 depending on brand. Jesel Sportsman series are less dough than the Crowers, but I wanted stainless for the amount of street use my car will see.

I just listed brand new Comp Ultra's (BBC) with studs, guides, girdle and locks for $600 in the classifieds if anyone is looking for a decent deal on a Dart Pro 1 setup. All new except for one initial start up at time of engine build. Pics are in this post - click here to follow link.
 

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The piviot length change can also help a lot... especially on a SBC you can get the pivot longer which helps on higher lift geometry.

The other thing with setting lash is WHEN in the cycle you set it. I always set lash after the intake valve closes... 30-45° more, basically a bump. Then go to the next cylinder in the firing order. I had a customer with a stud mount deal who was getting annoyed at the lash moving around every 2 weeks and I had him switch over to how I do it and the problem stopped.

Bret
 

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Butch
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The piviot length change can also help a lot... especially on a SBC you can get the pivot longer which helps on higher lift geometry.

The other thing with setting lash is WHEN in the cycle you set it. I always set lash after the intake valve closes... 30-45° more, basically a bump. Then go to the next cylinder in the firing order. I had a customer with a stud mount deal who was getting annoyed at the lash moving around every 2 weeks and I had him switch over to how I do it and the problem stopped.

Bret
Like Bret said, on a small block you can go to a 1.650" pivot length and have much better geometry. On my 1.650" pivot length shaft rockers, I can move the rockers .100" either way (Right or Left) thus the reason the exhaust pattern is off, after adjusting it, it centers perfect. Also at mid valve lift, the tip/retainer is DEAD CENTER of the rocker shaft. Also notice how narrow the sweep is when the geometry is good (See pic)
 

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Butch
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One major issue with stud rockers is many people don't know how to properly set them up, even some engine builders.

When using a solid lifter, setting the stud rockers up correctly become even more important, here is why,,,

Say your cam calls for a .020" lash, you put a .020" feeler gauge between the tip of the valve and the rockers roller tip then tighten up adjusting nut, when the lash is set you pull out the feeler gauge, when you do this the rocker drops straight down the stud.

Now when the rocker moved up and down the stud, its now working at its ratio of 1.5 or what ever the rocker is that you have. Now on the lift cycle with a stud rocker, the rockers fulcrum has to be lifted straight up the stud until the fulcrum jams against the adjustment nut and this is where the lash is taken up, close to .020" tappet lift (If a stud rocker, due to no moving up and down, only pivoting at its ratio).

Most people don't pay attention here, when the rocker is moving up and down the stud taking up lash before the fulcrum jams against the adjusting nut to take up the lash, and after it jams against the adjusting nut it can now pivot at its ratio

The issue is, say you have 3/8" rockers, the stud is 3/8" but the shank is larger, and the fulcrum's hole is much larger than 3/8", it is designed to be on the shank at all times, 99% of engines out there don't keep the fulcrums on the shank. When the fulcrum is not kept on the shank, the valve train can get into a bind putting more wear on the rockers and/or guides
 

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once you go to shafts you will never go back lol shafts are the best less breakage and more precise its the only way to go
 

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Shaft mounted rockers are the shit, that's for-sure.. But I've seen more aluminum rocker arms break than anything else under a valve cover..

That's why I've got a lot of faith in my chro-moly rocker arm/ stud girdle setup..
 
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