I swear you have asperger's... right? SmileWavy

Thank you for your kind words.

I would be inclined to try 7068.

It is quite machinable in a T561-Temper.

http://www.smithshp.com/downloads/7068_SHP.pdf

It's wear resistance would be quite poor and although hard anodising may help this treatment would have a negative impact on fatigue life so the best method would be to add a hardened pad.

http://i197.photobucket.com/albums/a...psxkx4ovly.jpg

I think that these pads are a cemented carbide which could be made to the correct shape for a few Dollars each and located with a screw as shown in this example.

Thanks. I'm pretty confident I could make them (CNC).

Curious the moment weight differences between that AL rocker and a factory steelie?

Meaning, is it worth it?

Reason I'd do AL is ease of machining and cheap.

1/3 - but you will have to add in the swivel foot and the hard pad so still lees than 1/2.

You will need a bush for the shaft and I would use something like Colspeed 90 from Columbia Alloys and bore it in situ to a relatively thin cross section.

You may need to make the cold fit the minimum specified to cope with the expansion.

Chris,
When measuring my rocker I created a secondary datum directly through the axis of the screw adjust elephant foot. I allowed this to align with the Y axis to stop rotation of the rocker around the 18mm bore. How did you align your forged rocker drawing. This effects the distance of the 30mm radius to the center of the 18mm bore.

Good stuff, thank you!

We measured a factory RSR Rocker to make this drawing and why I only showed the foot area. I didn't want to share the fully dimensioned 906 Rocker drawing.

We made the 'Adjustable' Rocker about 2 years before we produced this drawing and the 'first generation' part was measured by the forging company and the only data they provided was a final forging drawing less data.

I have never been 100% happy with this area of our forged rocker and whilst they machine accurately and measure identically to an original 1965 rocker I am not happy with the 'visual' appearance.

This is the reason we have more accurately measured the 906 Rocker and have decided to 'coin' the finished forging.

Relying on the forging shop has resulted in a 'good' rocker but I want to make the next product to a higher standard of appearance.

Once we have made the 'lash caps' we will measure the adjustable rocker and the 906 rocker and compare.

I am reasonably confident that they will be the same.

We made a simple machining fixture using a 1965 Rocker and then made a checking fixture from the same part.

Sadly this means I don't have the data that you are looking for but as we plan to make Aluminium rockers at some stage I know we need to make more measurements in the future, probably early New Year.

Chris, that AL rocker has me salivating.

Good luck on your rocker endeavor, it'd be great to see more AL rockers out there.

Here is how I did mine.

Using the cross feed allowed an even amount of material to be removed across the foot of the lifter.

http://forums.pelicanparts.com/uploa...1482263874.jpg
http://forums.pelicanparts.com/uploa...1482263937.jpg
http://forums.pelicanparts.com/uploa...1482264010.jpg

Gordon
The radius of the face is not centered at the center of the rocker shaft. So did you hold finger pressure on the rocker while moving the feed in and out?

Yes, that is correct. I took two or three "cuts" to make sure the old wear ridges were gone.

Has anyone seen a factory new rocker with grind marks going perpendicular to the rotation of the cam like the rocker on the left? This rocker also has a noticibly rough finish on the bushing bore. http://forums.pelicanparts.com/uploa...1482721585.jpg

The visual marks may not be relevant depending on how they measure.

You need a certain Ra to ensure the optimum oil retention on a bi-metallic bearing and around 0.5μm should be OK with a maximum of about 0.8μm.

I would like to see an Ra on the rocker of about 0.04μm and a very easy method to produce this surface finish is to use a REM technique following grinding.

Is this required just for break-in? Meaning, once worn in, surface roughness can be smooth as a babies rear?

This is the new looking bushing. http://forums.pelicanparts.com/uploa...1482770953.jpg
I cam measure Ra next week. .5-.8 on bushing and .04 on face that rubs cam?

I would think that the bush is more likely to retain some measurable surface irregularity as the clearance would be between 0.02mm an 0.15mm so the oil film may minimise wear.

The sliding surface of the rocker may gradually wear but the relative hardness of the two surfaces will have an impact on how long this takes.

A DLC treated rocker will generally ensure that the cam wears first.

The oil film is always important and the reason we use the PVD process we have chosen is that the small degree of surface porosity that occurs during surface conversion means that an oil film is quite strongly maintained.

If the surfaces were perfectly smooth and the oil film was entirely eliminated wear could accelerate again depending on hardness levels.

Tribology is a complex subject and tends to be very application specific with small changes in surfaces causing significant changes in wear behaviour.

It may be best to determine the grade of grinding wheel used by companies that have a good track record of refurbishing rockers and use this material.

The Bi-metallic bushes are easier to deal with as Glyco and GBB publish good design data sheets which provide all of the required information.

Some small progress on the rocker arm tooling. I got a mandrel made up so I can hold the rocker by the bushing ID. Found a vendor with rocker arm bushings for a fair price. Ordered 14 bushings and they sent 13. It's cold outside, perfect weather for working on projects.
😁 Got in touch with Chris_Seven and we are working on details of an order of rocker arm shafts, valve guides, and a set of his titanium valve spring retainers. I am very excited by the parts he is designing.http://forums.pelicanparts.com/uploa...1484092096.jpg