Some roller cam detailed info (and new pics), I could not find the previous "roller" thread Options

[Jake Raby]

OK, finally got a few minutes to share some roller cam info....


Roller cams are the major factor that keeps the VW pushrod driven engine from being made more modern. All of todays modern pushrod engines use roller cams and lifters to provide valve actuation, due to this these engines can run on oils that do not have as much zinc and phosphorous contant and this is a huge factor that is driving all my engines to the roller technology.

Roller cams provide the following:

- More power than any flat tappet cam of similar characteristcs, due primarily to faster opening events.

- Less friction than a flat tappet as the roller wheel actually "rolls" on the cam lobe instead of depending on lobe tapers and lifter crown radii to spin the lifter (HUGE)

-The use of roller cams and lifters allows much small lift and duration numbers to be used to gain the same net power as a much larger flat tappet cam, this means better idle, better EFI system compatability due to a stronger and more stable manifold pressure.

It's no secret that we are doing the roller lifter development to meet two main objectives, the first being better compatibility with modern oils and the second to make more power. Roller equipped engines have serious throttle response compared to flat tappet cams and they also have serious torque curves due to the extreme chamber filling at lower lifts because of the ramp speed of the cam.

The friction reduction with these cams and lifters is a huge benefit, the way our roller lifters are designed there is virtually nothing to wear out as the engine gains age. The use of an 8620 tool steel camshaft blank coupled to the rioller wheel that is made from another grade of tool steel (for compatability) results in two components that are well lubricated, resistant to wear and resistant to failure either on the street or on the track.

My emphasis with this development has been 13 months in the making, the first 5 months was the simplest, basically sourcing materials, designing lobes and having the cam blanks made up from scratch. After this point the project was stalled due to one company going out of business, my schedule and all sorts of tooling issues with the case alignment tools we designed to install the bushings. The last six months has been full of ups and downs but last week we finally got the bushings installed the way that made me happy and with the latest revision to the toolimng is fairly simple for us.

This week we will be doing tests in the simulation device and then tearing down to measure wear, bushing aligment and etc. What will follow is a series of 4 different test engines being built with both roller and flat tappet cams for comparisons in power and tuning. After these four engines are completed this technology will be the standard here with all of my "Performer" based engines using the technology by mid 2008 at the latest.

I'll close by saying this development is being made primarily for STREET engines, not race engines! Most every racing venue that exists for the 914 has rules that do not allow for roller camshafts to be employed- when something is made illegal by a racing body you can bet that it really works and gives it's users a huge edge-

Here are some detailed pics, I have shared more similar pics over at my forums in the R&D section.


Here are some of the bushing alignment tools used to check bushing install to ensure the roller lifters are going to be truly perpendicular to the camshaft


This is a digital plot from our cam profiler that clearly shows the differences between a roller and flat tappet cam that have the same .050 duration values and similar lobe lift, note how much wider and flatter the 9900 series camshaft is, this and all 9900 series cams are rollers.


So, there ya have it, couple these to a pair of porkies heads and 300 REAL HP was never made so easy or reliable before. (IMG:style_emoticons/default/boldblue.gif)