Mid lift rockers

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kimosabi
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Re: Mid lift rockers

Postby kimosabi » Thu Aug 31, 2017 5:34 am

"You, sir, do not understand the Mid-Lift Standard or its intentions. but please don't feel singled out--most people misunderstand it."

Funny you should post that because my idea of setting up valvetrain is always about getting cam info to the valve with minimal loss, while minimize wear and harmonics. So what's the superduper mid lift idea of valvetrain geometry then? Market simple math as your own invention and try to capitalize on that?

"Where the roller tip rests (or sweeps) atop the valve stem has nothing to do with valve train geometry. Also, there is a lot more to Mid-Lift than just applying the much-paraded "minimal sweep" theory."

Well yes it does have alot to do with valvetrain geometry. Minimal sweep advantages should be obvious. Rocker arm length and stud length affects the geometry in every way. I never stated a short sweep is the be all end all but your statement right there doesnt make any sense. Are you sure YOU have understood the mid lift theories?

Ladies and Gentlemen, here we have a long time dealer for Miller who believes in one of his products. Props to you man but multiquoting full pages with poor rebuttal attempts and assumptions is in the same spirit as the miller seller approached my email with. Not trustworthy. His rockers may or may not work as intended for a specific application. That is all.

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Re: Mid lift rockers

Postby stealth » Thu Aug 31, 2017 8:34 am

So did Mid-lift rockers misunderstand that aluminum is NOT the best choice in materials for a rocker arm?

You are correct ... cup teams, may of whom use a certain big name engine supplier use their own very long ratio steel rockers now.

I'm not looking to start anything, but this whole mid-lift is being sold as the be-all end-all in design, yet never ventured outside the "aluminum" rocker arm box.

My point is things are always evolving..... I strongly encourage him to get back into the rocker business if its a better idea. Maybe get away from the roller tip and use better materials and coatings... the options are open...we welcome improvement!
The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself. Therefore, all progress depends on the unreasonable man.

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Re: Mid lift rockers

Postby Steve.k » Thu Aug 31, 2017 9:27 am

It is interesting how a simple question of has anyone ran these rockers can morph. I
Beleive paul said they are one of the strongest aluminum rockers? He did not say they were the best choice for rocker strength ?Ive read millers therory and like most It was a lot to take in. I beleive miller like most entrepreneurs started with alloy because of cost, and when your competing with companies like Comp,Jesel, crane and the likes its tough to get foot in door so to speak. The Tucker automobile comes to mind if you catch my drift.

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Re: Mid lift rockers

Postby stealth » Thu Aug 31, 2017 10:14 am

Steve.k wrote:It is interesting how a simple question of has anyone ran these rockers can morph. I
Beleive paul said they are one of the strongest aluminum rockers? He did not say they were the best choice for rocker strength ?Ive read millers therory and like most It was a lot to take in. I beleive miller like most entrepreneurs started with alloy because of cost, and when your competing with companies like Comp,Jesel, crane and the likes its tough to get foot in door so to speak. The Tucker automobile comes to mind if you catch my drift.


My point exactly! Why would you TRY to compete on cost when you have a "superior Idea".......

I worked with one of Tucker's grandsons for a few years actually.........Nice Guy.
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Re: Mid lift rockers

Postby Steve.k » Thu Aug 31, 2017 10:33 am

Well i would say he patented his therory so it could not be stolen. Then headed into manufacturing. Im in on a little manufacturing project right now and can tell you without a doubt theres alot more involved then anyone can imagine. Im assuming he went with alloy 1.for cost and ease of construction 2 likely 80% of rocker sales are in this category and 3 his theory would offer as much strength to a alloy rocker as a conventional stainless or close. So it was his best option. It would not be the first time someone with a great idea was squeezed by the bigger corps waiting to gobble up the idea or simple wait till patent runs out. Kinda sucks if ya ask me!

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Re: Mid lift rockers

Postby Paul Kane » Thu Aug 31, 2017 12:18 pm

kimosabi wrote:"Where the roller tip rests (or sweeps) atop the valve stem has nothing to do with valve train geometry. Also, there is a lot more to Mid-Lift than just applying the much-paraded "minimal sweep" theory."

Well yes it does have alot to do with valvetrain geometry....Are you sure YOU have understood the mid lift theories?

Ladies and Gentlemen, here we have a long time dealer for Miller who believes in one of his products. Props to you man but multiquoting full pages with poor rebuttal attempts and assumptions is in the same spirit as the miller seller approached my email with. Not trustworthy. His rockers may or may not work as intended for a specific applicabtion. That is all.
kmosabi, look again at my earlier responses in this thread: I did not come here attempting to sell rocker arms or defend your personal experiences outside of this discussion forum, I only logged in to correct and/or clarify general beliefs regarding Mid-Lift. The statement that I "was" (not "am") the west coast distributor for ten years was to establish my understanding of Mid-Lift and qualify my ability to answer questions.

Also, yes, my statement that "where the roller rests atop the valve stem has nothing to do with valve train geometry" is absolutely true and correct.
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Re: Mid lift rockers

Postby Paul Kane » Thu Aug 31, 2017 12:23 pm

stealth wrote:So did Mid-lift rockers misunderstand that aluminum is NOT the best choice in materials for a rocker arm?

I'm not looking to start anything, but this whole mid-lift is being sold as the be-all end-all in design, yet never ventured outside the "aluminum" rocker arm box...

stealth, exactly why is aluminum "NOT" a good material for rocker arms? Is Jesel, T&D. WW, Crane, Miller, Harland-Sharp, and all the other aluminum rocker arm manufacturers wrong to use it? Of course not. Aluminum has worked excellently in performance automotive rocker arm applications since the 1950's. More specifically there is no ideal material for rocker arms, there are (thankfully) material options which should be dependent on design, application & usage, etc. Just like con rods being steel or aluminum or titanium, or pistons being cast or forged or hypereutectic, or cam cores being steel or cast iron, and so on. There is no "best" material for a given engine component, only material options depending on suitability and application. And aluminum is certainly a more than viable rocker arm arm material.

By the way, Miller Engineering did produce steel rocker arms as well, not just aluminum ones. And they would certainly have design and material updates on any new manufacturing as would most manufacture companies. But I didn't go there because that is not the topic of discussion in this thread.
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Re: Mid lift rockers

Postby In-Tech » Thu Aug 31, 2017 10:42 pm

Paul Kane wrote:Also, yes, my statement that "where the roller rests atop the valve stem has nothing to do with valve train geometry" is absolutely true and correct.


I totally agree with this and have stated quite a few times on this forum, the naysayers seem to disagree. Math is Math, if I have the geometry correct and my tip length is not correct, well, guess what? Order some new rockers and start the fack over. This isn't rocket science, it's friggin geometry. It seems that the people that only care about sweep are the people that wouldn't have a prayer of making a 11,000 rpm multi angle canted BBC pushrod engine.

I never heard of this mid-lift theory until this site, it's not bad from what I have read. I have not had the opportunity to have one of the rockers for a specific application in hand. It seems very similar to what I was lucky to have made back in '94.

Anyway, I'll be quiet.
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Re: Mid lift rockers

Postby Geoff2 » Fri Sep 01, 2017 5:28 am

Aluminium is NOT the best material for rocker arms, as there is no way to test it's finite fatigue limit, before it goes 'bang ' [ Unlike steel ]
So lots of people use them [ not me ]. Lots of people also drive Toyotas, doesn't mean they are the best car on the road....

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Re: Mid lift rockers

Postby kimosabi » Fri Sep 01, 2017 6:21 am

Paul Kane wrote:
Also, yes, my statement that "where the roller rests atop the valve stem has nothing to do with valve train geometry" is absolutely true and correct.


Where the roller rest has very much to do with geometry because geometry is used to set up not only the motion of the valvetrain but also components of the valvetrain. It has EVERYTHING to do with geometry.

"This is absolutely true and correct." See, I can make facts too. Difference is... my facts are based on facts. And math. For petes sake, you don't know that radial motion, or just motion, is also a part of geometry?

For real?

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Re: Mid lift rockers

Postby DaveMcLain » Fri Sep 01, 2017 6:39 am

kimosabi wrote:
Paul Kane wrote:
Also, yes, my statement that "where the roller rests atop the valve stem has nothing to do with valve train geometry" is absolutely true and correct.


Where the roller rest has very much to do with geometry because geometry is used to set up not only the motion of the valvetrain but also components of the valvetrain. It has EVERYTHING to do with geometry.

"This is absolutely true and correct." See, I can make facts too. Difference is... my facts are based on facts. And math. For petes sake, you don't know that radial motion, or just motion, is also a part of geometry?

For real?


No, you're incorrect. Where the roller rests on the top of the valve stem makes no difference and has no meaning when it comes to rocker geometry. As long as the roller remains on the valve stem as it moves back and forth it really does not matter. Paul is right.

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Re: Mid lift rockers

Postby kimosabi » Fri Sep 01, 2017 7:47 am

I'm not talking about whether it makes a difference or not. Not one place have I stated that "it matters". I'm saying that geometry applies. Geometry is math. Math applies.

Assuming that people mean a certain way so that you can "teach" them otherwise seem to be very frequent among miller and his crowd.

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Re: Mid lift rockers

Postby MadBill » Fri Sep 01, 2017 8:03 am

Would it help to restate Paul's words as: "As long as the roller remains entirely on the valve tip throughout the lift cycle, its net location thereon has no effect on valve gear function or durability."
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Re: Mid lift rockers

Postby kimosabi » Fri Sep 01, 2017 8:28 am

Well saying that "it does not matter" depends too doesnt it. When you have a rocker with a slight twist because of stud/pushrod location and studs angle towards the valve, Like a typical small block head. How does the roller sit on top of the valvestem? :wink: We're not even talking about the push on the valvestem anymore. Now we're talking placement.

Oh I guess geometry have nothing to do with that either huh.

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Re: Mid lift rockers

Postby DaveMcLain » Fri Sep 01, 2017 8:38 am

kimosabi wrote:Well saying that "it does not matter" depends too doesnt it. When you have a rocker with a slight twist because of stud/pushrod location and studs angle towards the valve, Like a typical small block head. How does the roller sit on top of the valvestem? :wink: We're not even talking about the push on the valvestem anymore. Now we're talking placement.

Oh I guess geometry have nothing to do with that either huh.


The roller wheel will rest at a slight angle and depending on how much slop there is in the system it is possible that it would only contact the end of the valve stem on one side of its roller. The pushrod is also out of plane and this causes the rocker to have a small amount of side to side movement too which is not ideal. But if you would have read what Miller wrote about valve train geometry he specifically states that this sort of rocker placement should always be avoided and it is one of the reasons why he used aluminum bodies for his rockers because he also made them with offset built in to correct this sort of thing.


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