Sourcing Roller Rockers

[jcsb]

Well I've tried to get in touch with Rocker Arms Unlimited and while I've gotten a couple of emails I can't get them to respond to phone calls. I know Denis Welch, AH Spares, Cape, and Healey Factory. I want (not need) a set of roller rockers for my rebuild. I haven't been able to find out much though other than it appears that these (except Healey Factory) are really faux roller rockers. They are really just bushed aluminum rockers with a roller end and not needle roller bearing. The Healey Factory sells a DMD which is like $3100.00 (ouch) that has needle roller bearings rocker arms, but really that is ridiculous. Anybody have any information about another source or someone selling real roller rockers?
John

 

[Mike Dale]

John,

I don't have a good answer for you. But having just gone through the rebuild process for my BJ8 I do see the opportunity to do something better here. The engine I re-built had a pretty well documented 60K miles on it. It had been pulled from a wreck in the late 60's. When we got into to it, we found the rocker arm assembly really did need all new bushings. I am not sure if they were just not getting enough oil or maybe it was just poorly filtered oil with the original filter system. If there was that much metal on metal friction, the roller rockers might really be a good upgrade.

Mike Oshkosh, Wi

 

[Bob_Spidell]

Only tangential to the topic, but I've heard/read that using roller bearings where the movement of the parts is limited--in this case rocking back and forth only a few degrees--can cause uneven wear on the roller bearings and the enclosing surface. IOW, the rollers are just going to move back and forth a small distance and will not rotate completely, causing more wear in some areas and little or none in others (possibly wearing grooves in the races). In other applications--like the 'needle' bearings in gearbox gears--the bearings can rotate fully and wear is not so concentrated. Can anyone speak to this with authority/experience?

As prone to wear as they are, bushings may be the best solution in this instance.

 

[jcsb]

Only tangential to the topic, but I've heard/read that using roller bearings where the movement of the parts is limited--in this case rocking back and forth only a few degrees--can cause uneven wear on the roller bearings and the enclosing surface. IOW, the rollers are just going to move back and forth a small distance and will not rotate completely, causing more wear in some areas and little or none in others (possibly wearing grooves in the races). In other applications--like the 'needle' bearings in gearbox gears--the bearings can rotate fully and wear is not so concentrated. Can anyone speak to this with authority/experience?

As prone to wear as they are, bushings may be the best solution in this instance.

So I guess from reading this you mean that a design that is made to reduce friction will end up causing more wear. Hmmm, well I would think a properly designed roller rocker should out perform a a bushing. While you note that it's not moving much I would say it is probably moving at least 15-20 degrees. Also the needle bearings are free to rotate and do not necessarily stay in the same location. Considering roller rockers are not a new design, but have been around for many years, I feel comfortable with using them.
John

 

[Randy Forbes]

An alternative to reducing friction; dry-film lubricant on the rockershaft, bush and rocker tip, adjusting screw, push-rod, lifter, cam-lobe, etc., etc., etc.

 

[Bob_Spidell]

So I guess from reading this you mean that a design that is made to reduce friction will end up causing more wear. Hmmm, well I would think a properly designed roller rocker should out perform a a bushing. While you note that it's not moving much I would say it is probably moving at least 15-20 degrees. Also the needle bearings are free to rotate and do not necessarily stay in the same location. Considering roller rockers are not a new design, but have been around for many years, I feel comfortable with using them.
John

I posed this as a question--anybody have experience with the needle bearings causing greater wear? Yes, roller bearings reduce friction, but you're also reducing the surface area of the load. Just wondered if anybody has put, say, 100K miles on a 'true' roller rocker and if there was any evidence the needle bearings wore into the shaft. A quick google only produced this: https://mgaguru.com/mgtech/gearbox/gt204.htm (yes, it's about gearbox bearings, not rocker arm).

 

[Keith_M]

This is a really interesting discussion about the advantages/disadvantages of roller bearings. I don't have the technical expertise to contribute to that part of the discussion, but on the issue of trying to obtain roller rockers at a reasonable cost, I would note that replacing the rocker shaft and rebushing the rockers is one of the cheapest and easiest things you can do on an engine. At some point, it's probably cheaper just to fix the damage every 50 or 100K.

 

[jcsb]

I posed this as a question--anybody have experience with the needle bearings causing greater wear? Yes, roller bearings reduce friction, but you're also reducing the surface area of the load. Just wondered if anybody has put, say, 100K miles on a 'true' roller rocker and if there was any evidence the needle bearings wore into the shaft. A quick google only produced this: https://mgaguru.com/mgtech/gearbox/gt204.htm (yes, it's about gearbox bearings, not rocker arm).

The needle bearing on a roller rocker is not a caged bearing where individual pins are separated from each other. Also they are quite short in comparison to other needle bearings, say in transmissions. I did notice where Healey Factory (DMD) offers this type of arrangement in there roller rockers (got a love the Aussies). The only problem is there solution while being very interesting replaces more things than I wanted to. As for cost and 100k miles that went out the window a long time ago.

John

 

[Bob_Spidell]

It's been pointed out to me that using roller bearings in this application is similar to using them in universal joints. Anybody dissected a U-joint with, say, a 100K miles?

 

[Bob_Spidell]

Turns out there's a word for the phenomenon: 'brinelling' (https://en.wikipedia.org/wiki/Brinelling)

 

[jcsb]

It's been pointed out to me that using roller bearings in this application is similar to using them in universal joints. Anybody dissected a U-joint with, say, a 100K miles?

U-joints see grease occasionally, where roller rocker bearings see oil constantly. Pretty much a stretch in comparison. BTW we still use universal joints. So you do no maintenance in 100k miles? Performance engines are maintained more often.

John

 

[jcsb]

Turns out there's a word for the phenomenon: 'brinelling' (https://en.wikipedia.org/wiki/Brinelling)

We actually use Rockwell in this country.

John

 

[dwalpole]

U-joints see grease occasionally, where roller rocker bearings see oil constantly. Pretty much a stretch in comparison. BTW we still use universal joints. So you do no maintenance in 100k miles? Performance engines are maintained more often.

John

The issue isn't with grease or oiling. It's like leaving your couch sitting in one spot on the carpet for an extended period. It will leave dents, but if you move it constantly the carpet rebounds. So. If the needle bearings don't roll they will damage their races. That's why on cars the engine and differential are never perfectly on line with each other. They are off by a degree or so (vertically or horizontally) to force the roller/needle bearings in the U joints to roll. So in the Valve train the rollers need to move at least a little or they will end up damaging the rocket shaft and/or the rocker arm.

 

[jcsb]

The issue isn't with grease or oiling. It's like leaving your couch sitting in one spot on the carpet for an extended period. It will leave dents, but if you move it constantly the carpet rebounds. So. If the needle bearings don't roll they will damage their races. That's why on cars the engine and differential are never perfectly on line with each other. They are off by a degree or so (vertically or horizontally) to force the roller/needle bearings in the U joints to roll. So in the Valve train the rollers need to move at least a little or they will end up damaging the rocket shaft and/or the rocker arm.

That's the first time I've ever heard that remark. Not trying to discredit your remark, but the reason that a drive shaft is not in line is because the rear axle travel up and down and requires movement. This is why your drive shaft yoke is splined to allow that movement (in it's case in and out). If you see the trucks around here and possibly there which have lift kits the universal joints go out every 10k miles or so. Sorry, the grease and oiling is an issue. Grease as it heats (all bearings heats it's called friction) tend to make the grease break down and migrate. This is one of the reasons that they also have seals is to try and keep the grease internal. When a bearing breaks down it is either from excessive load (beyond it's rating), a lack of constant lubricant, or age associated with metal fatigue. Now to argue the point I would go for the excessive load since this is where the argument might lay. Since roller rockers have been use for many years in high performance ohv engines I find the point moot. The real point was whether anyone new of someone who made roller rockers with real roller bearings for the Healey. I have only been able to find the Healey Factory as being the only people to offer one and that is really a wild setup, where the valve cover is part of the valve train (very interesting), but further than I want to go.

So, I have decided to go a different rout altogether and utilize part of the original design with some improvements.

John

 

[jcsb]

An alternative to reducing friction; dry-film lubricant on the rockershaft, bush and rocker tip, adjusting screw, push-rod, lifter, cam-lobe, etc., etc., etc.

Randy,
Which dry film lubricant are you using? There are many on the market and having been a manufacturing engineer for 45 years I've seen many go in and out of vogue. I can think back to one in particular that was a nickle plate with teflon impregnated. Also a lot for different applications from preventing thread galling to corrosion protection, plus many different application techniques.
John

 

[Randy Forbes]

https://techlinecoatings.com/hi-performance/bs-internal-engine-coatings.html I use their "shop only" (solvent based) products, and can't speak of the ease of application of their consumer (water based) line.

TLML is one of my primary coatings, TLTB, TLHB & CB-1 (-2) are also part of my standard arsenal.

I haven't built an engine without polymer coatings since 1992. I'm not posting this here to participate in a debate; when a product or technique works for me I use it, someone else's argument against it is going to be one-sided.

BMW ///M3 S-54 engine:

 

[jcsb]

https://techlinecoatings.com/hi-performance/bs-internal-engine-coatings.html I use their "shop only" (solvent based) products, and can't speak of the ease of application of their consumer (water based) line.

TLML is one of my primary coatings, TLTB, TLHB & CB-1 (-2) are also part of my standard arsenal.

I haven't built an engine without polymer coatings since 1992. I'm not posting this here to participate in a debate; when a product or technique works for me I use it, someone else's argument against it is going to be one-sided.

BMW ///M3 S-54 engine:

That's what I'm looking for, someone who has actually used something. I will look into it since the engine is out and I'm getting parts together.

John

 

[dwalpole]

John,

I have no problem admitting when I'm wrong, but I also expect those who claim so to prove said point. I work in a job where being right is a mark of pride and we work extremely hard to be more knowledgeable, skilled, and practiced than our advesaries to ensure that the right people live or die. So here is the proof of my position.

https://www.hurst-drivelines.com/files/Universal_Joint_Alignment_Proc_111606.pdf

There are two major flaws in your argument.
1. On an IRS car the diferential is fixed, as is the engine (Given: there exists some flex to the diff/engine mounts), but the two do not move significantly in relation to each other as they would in a live axle rear end.
2. The reason you see U Joints failing on over lifted trucks is because they are operating at the other end of the envolpe and bouncing off maimum deflection limits of the U-Joint.
BL: U-Joints have a minimum and maximum recomended deflection to avoid failures. (See pdf above, They even use the term brinelling)

Minor point:
1. Both grease and oil break down/lose viscosity when heated - Its why your oil pressure will drop as your engine warms. Fortunately for engine parts we recylce the oil with the pump. And, use seals on differentials, U-Joints, Wheel bearings, etc. to attempt to contain the grease or gear oil. In either case the lubricant provides continuous lubrication until the oil pump fails or the seals fail and the grease runs out. That is why we change our oil and regrease our U-Joints and Steering components.

Lastly you touched on one of my biggest pet peeves. Grammar. You took 15 minutes to type your response, please take 2 minutes to read it and make sure your spelling and grammar are correct.
A bearing heats, multiple bearings heat.
Roller rockers have been 'used' for many years.
Route is a path chosen or available, rout is to dig out or beat severely.
Utilize means to use an item for an unintended purpose, whereas use means to use an item for its intended purpose. For example, "I utilized my valve cover as a serving dish for a barbeque. Now, I will use it on my engine."

 

[jcsb]

Dwalpole,
I guess that is what you want to be called. I'm pleased the internet served you by finding an article by Hurst (bought their shifter once). I had to go back and see what your original comment was about (carpet).
You said: "Valve train the rollers need to move at least a little or they will end up damaging the rocket shaft and/or the rocker arm."
Roller rockers move between 25-30 degrees dependent on what ratio and cam your using.
Needle bearing have been made and used for many, many years. There used as thrust bearing, roller shaft bearings, etc. You might find it useful to review the major manufacturers in the USA and Europe as they make roller bearings. Case in point: https://www.timken.com/EN-US/PRODUCTS/POWERTRANSMISSION/PRODUCTLIST/AUTOMOTIVECOMPONENTS/Pages/RockerArms.aspx

On your 2 major points I'm not sure what your trying to say? The reason for any universal joint is to transfer power or position between 2 points that are or might be become offset. The more extreme the angle the more work you place on the joint, except in conditions that are low speed. Such as a steering column.

On your minor point I would say that this is why you have a multi-viscosity oil. It compensates for heat generated by your engine and increases the viscosity. Yes, oil breaks down just like grease, but oil is change usually on a schedule with a filter to insure some degree of filtration. Most automotive ball joints and universal joints no longer have grease fittings. We can argue that point, but generally it's because many times people filled a universal joint until grease came out of the seal or didn't clean the grease nipple well enough and introduced dirt into the system.

Also on your pet peeve, I would suggest you get some help on that. I worked in an large engineering firm where I would estimate 85% of the other engineers sucked at grammar too! Sorry, but you should check your spelling.

I should note that I'm in the middle of a full rebuild and this is really taking up to much of my time. So I will end it here.

John

 

[dwalpole]

jcsb,

Firstly, I apologize for my spelling errors in my previous post (adveRsaries, difFerential, envELOpe, maXimum, recomMended, It's, and recyCLe). As I said, I admit when I'm wrong so I can learn from my mistakes. Thank you for your help. I also apologize if you feel I'm taking up TOO much of your time. I assumed, since you were posting TO the forum that you welcomed lively and spirited debate between TWO or more people. Clearly, I was mistaken.

You missed the point of my original comment. The first part was, both valves and U-Joints are lubricated and while the lubricants are different, as long as there is not a failure of the system (oil pump or seals) the lubricant will continuously do its job. Therefore, oiling or grease is not the issue. The second part was, brinelling will occur to any surface be it the rocker shaft, or U-Joint races, or carpet, or your front yard if a stationary load is placed on it. How deep the dent will be and how quickly the damage will occur, changes based on the surface strength (Rockwell scale value – which is the test derived value, not the damage caused) and the load values, but the damage will occur.

Saying the ratio of the rocker arm determines its angular movement is not a complete answer. Certainly the change in radius of the cam lobe imparts a linear movement to the pushrod. The angular movement of the rocker is then determined by the length of the arm of the rocker on that side (measured from the center of rotation to the contact point of the pushrod) in relation to the movement of the pushrod. If that doesn’t make sense I will happily give you an example (you seemed to not like my last one). The ratio of the rocker arm only determines the multiplier for the movement of the valve in relation to the pushrod.

All of which ties back to my original statement that if the rocker arm does not rotate sufficiently the roller bearings will essentially be static and will damage the valve train. The same will happen to a U-joint with no flex, reference my previously posted link.

In future, if you wish to quote me, please use the full sentence or an ellipsis or brackets as appropriate rather than a truncated non-sentence.

The Hurst article, which you apparently did not read, was simply the most conveniently packaged supporting document I found. Also, Hurst, as a major manufacturer of driveline components has some authority when it comes to proper driveline installation and maintenance. There were several articles and forums making the same statement I did. You can Google it any time you like.
As to your “I worked in an large engineering firm where I would estimate 85% of the other engineers sucked at grammar too!”, better make it 86% and drop the other (assuming you had 100 engineers in such A large firm).

Enjoy your rebuild and I am happy to leave this here or continue, but I have a war to fight.

Don