As stated above try a different rocker , even a stock one to see what angle they are at. It seems to me the one you are checking is way off unless you have longer valves installed. If thats the case then you'll need different rockers or machine work. Caution, shims will split your rocker shaft stands so that is not the way to go. There are special shims but they are machined to fit the contour of the shaft .

The machined part of the adjuster has to be where the hole is in the rocker body. I think the machined part is about three threads wide, so if you are out side that range, the threads of the adjuster cover up the oil hole in the rocker body. What size cam? I look like maybe 0.500" lift. The angle is not too bad, remember that the pressure on the pushrod/adjuster is lowest when the valve is closed, and greatest when the valve is open.

If he just raises the shaft, he will likely have rocker/retainer issues.

You just can't raise the shfts. You have to raise the shaft and move the shaft AWAY from the valve.

The best example of this is the W-2/5 stuff. You had offset stands AND shafts. If you drew a line through the valve guide and then drew a line through the stand, you would see they eventuallwill intersect. Follow the lines far enough, and you would have the C/L of the shaft on the other side of the valve.

B3 Racing has the best kit to fix this.

Otherwise, mill the stands and use blocks.

Thank you to all who have spent time trying to help me on this.

So what is the culprit? Madscientist is saying the rockers are fine but the geometry is off. What is causing the issue?

I'm glad to know B3 has a fix but I'd like to know what is "off" causing the problem? Heads? Rockers? Head components?

On my last 440, I had Edelbrock Performer heads with crane gold rockers and a solid cam....I didn't need to do anything special for geometry, just proper adjustment.

I'm going to call Dunnuck Racing tomorrow and ask if he's had any similar issues with setting up these heads.

-Dan

What is "off", is the roller on the tip of the rocker. Any roller rocker, not just PRW. When you bolt a roller rocker on a cast-in stand that is positioned for a non-roller rocker, the geometry changes and is no longer correct. Other changes to the valvetrain will throw it off as well. You need to put the shaft at the right place for your application. A search for rocker geometry here will give you enough information to make your head spin.

^^^^^^^^^^^^^^^^^^^^^^^^^^THIS^^^^^^^^^^^^^^^^^^^^^^^^^^^^

You can buy ANY rocker arm and STILL you will have to fix the geometry issue. The brand does NOT matter. You can't expect to bolt on parts from different masnufacturers and have them work can you? You didn't buy a "system" did you...where the heads/camshaft/lifter/rocker/shaft/stand were all engineered to function together? You cnage one thing in the equation and you will need to correct geometry. Hell, I just forgot to include valve length (stem height).

All these years using shaft rockers and the Chrysler guys still don't get it.

Your rockers are fine. Block out all the nattering naybobs and just deal with Mike at B3. Use his corrections and your stuff will be fine.

Can't tell by just looking at pictures and I haven't run Sidewinder heads - but in 30 years of doing these, I've never needed B3's approach. IMO you need a decent cylinder head guy that knows shaft rocker systems. The valve job sets the geometry on a factory type shaft rocker system.

On a bone stock spec motor, the valve job and the resulting stem protrusion puts the geometry back to factory correct. If that's what you're talking about, then you should be in the restoration forum.

Virtually nothing about a performance or race motor valvetrain is factory spec, and the resulting geometry is pretty nasty sometimes, regardless of the valve job.

Here are some pics of the PRW rockers with corrected valve side geometry, and the pushrod angle is a lot straighter on the seat than what the OP is seeing. .560 lift with a 1.6 ratio= .030" sweep.

Sorry about the upside down pics. They are right in my phone gallery. Oh well, you get the idea.

The previous 496 certainly won stock appearance, but the 480hp at the tires isn't. That runs Cranes on Stealths with .040 sweep. 505" years ago, RPMs with Cranes - .040 sweep. 451 with Indy SRs in the 90s when they first came out w/Indy rockers - .045" sweep. None used "as delivered" valvejobs. Stock resto? I understand you're trying to build a market share, but please...

Ok, we obviously have different ideas on what geometry is. I'd like to hear your explanation of proper rocker geometry. I'm sure there are many others who are interested as well.

Mike, thats like 1/4" of spacer under that shaft? what heads are those? no wonder ppl have issues...

OP - Are those the valves Dannuck supply? do you know what brand they are? have you checked the installed height? Dwayne Porter has gone to SI's (never heard of em?)

Just to thread jack a little, who supplies 11/32 valves for these sidewinders, edelbrocks and stealths? all the high end ones im looking at are 3/8, the only 11/32 on summit are edelbrocks. No listings for ferrea or mildon anywhere (inc their catalogs)*

edit *have found Indy do some

You're pretty close, Alchemi. The spacers are .195" thick. The heads are pretty much OOTB Edelbrock RPMs and the rockers are PRW 1.6 stainless.

Its not the fault of any one part, but the combination of many non-stock spec parts. The shaft stands can not be correct for every combination. For instance, why doesn't everyone run the same camshaft? For a given application i.e. BB Mopar, they will all bolt in, just like the rockers will just bolt on. Or better yet, Why degree the cam? After all, it fits the block and the timing components bolted right on. It must be good to go, right? Just because it fits in a specific location doesn't necessarily make it right for the combination.


For valves, Ferrea has 6000 series, part# F6306 and F6307. 11/32 stem for Edelbrock style heads.

With the correct pushrods length and I select Crane rockers I can have a good geometry...

I'd like to know if the O/P has measured the lift at the valve with this set up.
IMO, the pushrod being closer to shaft side of the rocker will increase the total lift. This is because the point of lift begins closer to the pivot point. I'll bet the 1.5 Rockers will have lift numbers closer to 1.55 or 1.6 ratio Rockers.
I'm not saying to leave it, but there is a Youtube video by Racersresource, titled "More power through improved rocker geometry", that's worth watching.
By shortening the pushrod, the valve lift numbers increase substantially.
They summarize it at the end saying it's fine for a race motor, due to more lift, but not what you want for a 100,000 mile rebuild because of increased loads on the valve guide and such.

Hipparchus died in 120B.C. These engines were developed in the 50s. They've been in production since the 60s. Raced hard in all kinds of disciplines over the decades. Valvetrains developed and punished, parts engineered, parts broken and re-engineered. Did your math only recently come to light or has the racing community just been ignoring it all these years? (rhetorical)

It's my opinon - and only an opinion - that the offset shim solution can bring problem milder combinations into a more stable state for a reasonable cost. But that is as opposed to actually replacing the poorly interacting parts and/or fixing poor machining. I have a lot of respect for professional builders and innovaters. I myself have no vested interest in selling myself, a shop, or self-engineered parts. I am as impartial as one might find. I do not believe you share that impartiality - not that I have any problem with that because time always sorts things out. To me, you've built a better mouse trap when plugging the hole in the wall is the "correct" path. In those situations where true adustability in shaft centerline is needed for longer valves or different rocker configurations, my approach would be to machine the stands and use shaft support blocks. Shims of any sort may correct the centerline issue, but IMO lose stability when using high seat pressures these aplications typically need. In situations where lower price point parts have been used, or the valve job is not done properly for a shaft rocker system, it is a band-aid.
I could not for instance see Bob Mullen using cast stands and your shim package on the W2s for an all-out Pro Stock engine in the 70s. I don't see Jesel looking into this approach either.

Yup, and Newton died a long time ago as well. That doesn't mean it won't hurt if you fall off a ladder, because gravity is still there.

I know a lot of high end engine builders who set up their valvetrain this way. They just keep it to themselves. It seems the Mopar community is more inclined to ignore it.

I didn't post trying sell myself or my product. I responded to you trying to discredit a product you have never tried that was recommended by people who did. Do you do that for other manufacturers whose products you have no experience with?

I asked you to explain your perspective on what proper geometry is, and was willing to listen. I believe that was pretty impartial. I haven't heard that explaination yet.

You've made my point when it comes to application. If I'm working on high end stuff, I make new stands, but that's not necessary for most street or street/strip engines.

You mentioned Bob Mullen. He flowed cylinder heads at 3" depression. How many cylinder heads have you bought recently that were flowed at 3"? Things change, even for heroes of the 70's.

Another centered sweep that is about .060" wider than it should be. That has no effect on efficient valvetrain operation.

The lift increases substantially, and so does the velocity at full lift causing instability. Low lift velocity is very slow, choking the motor.

Don't get me wrong. I wouldn't leave my Rockers the way the O/P has posted in the picture.
I just believe there is a lot of misinformation on the subject.
I also believe that there are reasons that Ray Barton motors are at the top of their field. He has continued to look for more performance from his motors that others haven't figured out yet. But he's not going to run out and tell everyone what has taken him years to learn.
This rocker geometry issue is like that. Alot of people ignore it. Others believe the aftermarket manufacturers would point it out if there product needed special attention. I feel the manufacturers are caught in a hard spot. If one of them were to say, "when installing our rocker arms be sure correct the geometry problems that are relevant to shaft systems", there's a chance that the less caring crowd will decide to buy brand x instead because they don't mention that. I came to this conclusion with the 2nd set of headers I purchased. Nobody said to dent the tubes to clear the frame or that a ministarter may be required.
I'm sure that I don't know enough about it yet to jump on anyone's bandwagon. It has to make sense to me or I'll continue to study the problem until I see the light bulb.

And this is why I told the OP to contact B3. There are only 2 ways to fix this, and buying parts and changing pushrod lengths isn't it. Even lash caps are a band aid.

You eiter have to mill down the stands ans use blocks like a W-2 (which is what I was going to do for my current build until I found Mikes deal) or use Mikes deal.

It makes no difference what you change, but when you change ONE thing, it affects all of it. The OP has changed MORE than 1 thing; he has added a roller tip, he added lift and he added stem height (longer valves). That particular shaft height was established for .4xx lift, with a rocker than has no roller tip, and the stem height called out for in the book (which I do not remember off the top of my head, (I just remembered the OP changed the rocker ratio, so add that to the list). I would bet big $$$$$$ that the cylinder head manufaturer put the shaft in EXACTLY the stock location. So how can you expect the geometry to be correct? There is no F'ing way it can be. When you add all that together, you MUST move the shaft UP and towards the intake manifold to correct geometry. That's EXACTLY how it's done with W-2/5 stuff. Offset shafts and stands. It's not that hard to figure out. And yes, most guys have been doing it wrong for DECADES. Until this came along, we milled the stands off like the W-2 stuff and used those offset stands and shafts. I tunrned away many customers because they didn't want to spend the money to do it that way.

Now the B3 system makes it so you don't have to do all that work.

To the OP...as I said, the rockers you have are fine. You could buy red rockers, black rockers, gold rockers, shiny rockers...but in the end, you still have to correct for all the changes made to the valve train system.

It pisses me off when companies produce these aftermarket heads and they NEVER address shaft placement. It's not because they are stupid. It's because the Chrysler guy never wants to use anything but stock crap. It's retarded but its the truth.

OP...look at your head. Measure from the deck to the center of the shaft. Then measure a stocker. Wanna bet me they are EXACTLY THE SAME? But how can they be, when they come with longer valves? That right there means you need to move the shaft up and away from the valve.

Keep us posted. I hope you stop and think it through for a while. You will figure it out. B3's system is a quick, easy, correct fix. Otherwise. mill off the stands and use blocks.



BTW...I get NOTHING FROM MIKE. ZERO. But I use his stuff and will continue to use it, and hopefully get others to stop and look at rocker arm geometry from a different perspective than 90*/half lift or looking at a centered sweep pattern.