Thought you might be interested to see these.

Getting ready for final machining, then testing.

The design ratio is 1.73 : 1 as opposed to the 1.3 : 1 stock.

I’m using swivel adjusters from Thorsten Pieper.
Click to view attachment Click to view attachment

This is great! I am interested in how these are. I have used ratio rockers on Type 1 engines. Never knew why ratio rockers are not readily available for type 4.

Very cool! More details please!

They look cast aluminum? Oiling holes? Just curious how they look from a few angles.

They need to be alloy steel, forged or HIPed, IMO. Although printed may not be far off.

These are made from 316L SS, 3d printed. and not the final design- close, but still a proof of concept

I tried machined aluminum, patterned after LS type rockers - no bueno! So, I went back to the tried & true VW design.

These incorporate all the oil passages, and then some. I am also in the midst of trying to develop 2:00 ratio arms, too.

I am not trying to increase the total lift, but rather the rate of lift - as I don't see roller lifters as being practical... unless the engine case undergoes a complete redesign.

The high ratio lifters are an essential part of working toward a naturally aspirated 100hp/Liter engine (but its gotta be streetable and have a smooth idle w/ high vacuum!)

I will periodically share as the individual components are developed - these rockers are just part of what I'm trying to do.

And, I appreciate any and all advice/observations

Should enable larger base circle !!

Why are you making such a huge increase in the ratio?
Are you planing to make offset shafts?
What are you going to do for cam?

Even with a stock cam you're going to have crazy lift rates, dual springs will be a must to prevent valve float. Dual springs rob HP so you actually have to make more HP to overcome this. My 180hp 2.6 (T4 conversion in a bug) would likely make 200hp if I could have used single springs.
100hp/liter is a lofty goal, once you hit 45-50hp/jug you will have to use nickies.

The ratio increase is to increase the valve acceleration.
The geometry of the rocker shown is designed for direct installation. Nothing special will be necessary for these. The 2.00 ratio will need its own girdle for mounting.

The springs consume a tremendous amount of energy but from what I've seen, the real power robber is engine pumping losses

Yes, Nickies are the best

I realize what it does, my comment is you'll have to increase spring pressure to control that increased valve rate, or valve float will become a major issue. An old flat tappet pushrod design is a lot of weight to control, major reason why manufacturers went to OH cams.
1.73 on a stock cam is going to give about .520 lift, doable but that's a huge amount of lift to control.

I'd say a stock cam is about the only off the shelf cam that may work, to me the rockers are only the start of the battle. Custom ratio rocker specific cam grinds will be the next step in your endeavor. A ratio rocker is to reduce ramp rates, not so much to increase lift.
And then you will have another hurdle, the exhaust port is a bottleneck, you can't get it in if you can't get it out.

I do hope you plan to test and prove the product before you offer them up for sale.

Mark, I agree completely.
The rockers are only a small part of the bigger puzzle.
Although, by themselves, they may make a reasonable change.
And what you call bottle necks, I'm calling pumping losses - same idea
Bottleneck considerations are not only for the exhaust, but for the intake as well.
Insofar as offering them up for sale, this is just a hobby (along with blowing up engines).
Ever since I retired, the Type4 has become an obsession of sorts. LOL
and thanks for the comments -
any & all suggestions observations are greatly appreciated.

T4 2.0 914 intake ports actually flow pretty good, the exhaust ports needs work and there's only so much you can do. When I build T4 performance I only do clean up and blending on the intake, exhaust ports gets the most attention.

Cool, printed parts.

Just curious what processing (if any) is required after the part is printed (e.g. tempering, annealing, etc.). Also, is the part (CAD data file) slightly over sized and holes undersized for final machining to specification or does the part print within tolerances?

Forgive my ignorance to this amazing new technology.

Fine details are over sized / under sized to allow for the inevitable shrinkage the occurs

Threads are chased, and the I.D. must be machined - but other than that, its accurate

And, what ignorance? Its new to everybody!

As mentioned that a large increase from stock...wow,don't really remember but didn't the T1 kits go from 1.2 to 1.4 to 1 or so,think the drag race guys when to 1.5 or more using roller rockers with offset pivot blocks.
Do you plan to fit offset rocker pivot blocks to restore rocker geometry ?,no expert here just asking.
Mark is "dead on'' with his comments on the heads,the exhaust valve ports are horrible and all restricted by very small exhaust valves,still wonder why VW designed this way ? perhaps that why they went to square port for a short time ,you simply can't port them out enough to really benefit from larger valves...there is a limit with stock casting.
Hope member HAM chimes in here for comments on the stock heads.

Without re-locating the rocker shafts, you've reduced the offset from rocker C/L to the pushrod pocket. this orients the pushrods off center in the tubes and dramatically increases the pushrod loadings. Hope you've got very stiff pushrods. Without a lower cam peak lift, you'll increase total lift if using stock cams.

The primary consideration in this iteration was maintaining the CL to valve tip geometry, as I did not want increase side loading on the valve stem ( of note, the 2:00 ratio necessitates a complete rethink- one the benefits being less arc deflection on the valve stem);

With regards to pushrod offset, its approx 0.25 degrees from stock (don't hold me to this - I'm going off memory) and this wear consideration is one of the items I will be checking

Finally, the camshaft will have a lower peak... I want to increase the valve acceleration, not the total valve lift.

Thanks for the comments (I love the great peer review!)

Well, since you asked.

The thing about T4 exhaust ports is this: They get a bum rap. Across the board, every T4 head VW produced has a perfect ex/in port flow balance of around 75%. I've flowed them all and they all have this perfect balance in stock form. This is an excellent ratio and represents modern ratios that emerged in the "enlightened" era, when designers realized that 1:1 ratios were not needed (or helpful) in building torque. A way of thought that was firmly set in place by the mid 60's.

When it comes to T4 head modifications to both sides (by that I mean intake ports and exhaust ports) we have no trouble safely modifying the exhaust ports to maintain that target 75% ex/in port flow ratio with a 44mm intake valve.

We have also had plenty of success at exceeding 100hp/liter on high revving 1.8l & 2l 914 race engines with stock sized valves. Both ports need work but are easily up to that challenge. (Remember that the largest displacement factory T4 was 1971ccs, so obviously the designers did just fine with both ports for the intended use.)

In considering at what point the exhaust ports become a hindrance consider the current state of the art of normally aspirated ProStock drag racers who are running ex/in port flow ratios down in the 60% range.

We learned a long time ago that we can go way up on the intake port flow and still produce an exhaust port capable of keeping up over 60% (split duration cams are the norm for these engines), and producing gobs of torque on large displacement engines.

The issue that limits these large displacement engines is the simple fact that we can't fit a suitable size exhaust pipe between the pushrod tubes without pinching the exhaust pipe. With large displacement engines, the restriction becomes the exhaust system due to the location of the exhaust ports, not the exhaust ports themselves.

The facts outlined in the above paragraph are what limits the rev potential of large displacement T4's. We can crutch the decreased ex/in port flow just fine with split duration&lift cams and well designed exhaust systems, but we can't get a big enough pipe bolted to the engine. This is why the T1 port design opens the potential for large displacement T4's. Large displacement T4's are great for gobs of low-end torque, but if you want to rev them hard to make big HP you need to make the switch to aftermarket heads.

I do not remember off the top of my head at what lift point the stock springs go to coil bind, but it's not very high, and at any rate they do not have the pressures to handle aggressive lift rates.

Aggressive lifting will require dual interference springs for the pressure needed as well as to prevent destructive wave action.

I think it's great that the OP is willing to try new things and break parts along the way to greater understanding. I will say that in my professional opinion a 1.7:1 rocker will likely present valve train issues with any cam designed for stock ratios, and at high revs on cams designed for 1.5 ratios.

But, don't let me deter you from finding out on your own, and I will be quite pleased if you prove me wrong. Proof to the contrary is how we learn and make progress.

I did some development work on a stock ratio roller tip rocker, using a 356 adjustment screw (which installs on the pushrod side, instead of the valve side). Feel free to steal this and run with it. I think it has far more practical value to most Type IV engines. Gives you all the benefits of a 'swivel foot' without the cost, and a smaller lighter package. Roller tips are also much easier on valve guide wear, especially at fast lift rates.

*credit to @maddog for the CAD and 3D printing work

And to reiterate Len's sentiments:

I looked at a very similar arrangement, but because the valves are above the push rod, it appeared to me that an oiling spray bar would be necessary.

That's why I went back to what is essentially a modified VW design, with enlarged oiling passages.

But I love the idea of adjusters being on the pushrod side.

Now, if the valve arrangement were flipped, like the Lycoming engine, with the cam on top...

There's an oiling hole from the pivot shaft to the valve tip on the stock adjuster. I figured that, + splash oiling, + knowing the valve covers fill with oil under high RPM, there wouldn't be oiling issues. But that was my 'try it and see if it breaks'.

Looking forward to how yours turns out.

Thanks for the comments

and wish me luck...