powermechanics.com

*Baker Consulting Camshafts and Cam Data*

The aftermarket industry is filled with camshaft designers and grinders, from large conglomerates like GM, Ford etc., to aftermarket leaders like Crane, Comp Cams, Lunati, Iskendarian, Crower, and a host of small specialty cam grinders who the average consumer never hears about.
In my pursuit of greater knowledge regarding camshaft design and the effects of different profiles in engine combinations, I have made an investment in the necessary hardware and software to measure and evaluate cam profiles beyond the normal "published" specifications provided by the various cam manufacturers.

My intention is to explain and illustrate not only how a cam is manufactured, but what some of the data that is available looks like after analysis by different programs.

Why do I care, Why should you care?
Camshaft Definitions
How A Typical Cam Is manufactured
What Is A Cam Doctor?
Analysis of Camshaft Data
- Cam Doctor Data
- Cam Pro for Cam Dr Data
Links to Camshaft Manufacturers and Others

Why do I care, Why should you care?

I have been involved for many years in the building of performance engines, not only for myself as a hobby while a teenager, but by now as a full time occupation. I have always been fascinated by camshafts, and the effects that the cam has on the power and performance of the engine. If the cylinder heads of an engine are the "HEART" of the engine, the camshaft is certainly the "BRAINS", and a complete understanding all the effects of cam design on different engine combinations is not something that can be explained even after years of experience.

You should care about accurate analysis of your racing cam because:

The valvetrain of the average pushrod V8 was never designed to operate at current racing speeds
Many mechanical failure issues are possible without proper setup
The average manufacturer's cam card does not have accurate information that YOU the user/purchaser needs to properly set up your engine
Broken valvetrain is almost always catastrophic to the rest of the engine
The performance of the engine will never be realized unless the valvetrain is operating smoothly

If you are interested in knowing more about your valvetrain combination, see the SERVICES page.

TOP OF PAGE

How A Typical Cam Is Manufactured

While more and more cams are ground on "CNC" cam grinders, most performance cams are still ground on machines similar to this. The "Master" plate is the actual cam profile, which the machine transfers to the cam core.

There are two things that I feel are important when evaluating a camshaft:

The accuracy of lobe to lobe variations, and quality of the surface finish, which are good indications as to the tolerances of the cam grinding machine, and the skill of the machine operator.
The actual shape of the cam profile when broken down into the velocity and acceleration curves. This is where a proper comparison can be performed of different profiles which otherwise have similar lift and duration specifications.

TOP OF PAGE

What is a Cam Doctor?

As a tool to assist in understanding why a particular cam "A" might outperform cam "B" , even though the published specifications might be almost identical, I acquired a tool called a "Cam Doctor" , which is a computer assisted device specifically designed by Quadrant Scientific (unfortunately no longer in business) for the purpose of measuring cam profiles. With very accurate measurements possible, subtle changes in the actual profile can be measured and compared, and the differences in cam profile design and quality can be uncovered.

The stand is a purpose built fixture which supports the camshaft with "V-Blocks", and has a sliding indicator mount with the linear displacement gauge (basically an electronic dial indicator) for lobe measurement. An optical encoder mounted to one end of the cam measures rotation at the same time.

Resolution of the linear gauge is .00003937", and the rotation encoder 1/10 degrees.

TOP OF PAGE

Analysis of Camshaft Data

The Cam Doctor data consists of 360 data points for each lobe tested, with some other data that contains averages, offsets for the lobe numbering and location in the engine, and setup notes.

While the Cam Doctor data is very accurate (if the operator was careful while measuring!) , the presentation of the data in graphic form, especial for printing, is very poor.

See some EXAMPLE SCREEN SHOTS of the Cam Doctor program.

Fortunately, there are several software products that can convert the Cam Doctor data into more useful forms...

Audie Technology is the manufacturer of "CAM Pro PLUS" , an alternative measurement system that offers a complete camshaft testing solution, with their own measurement stand, data collection hardware, and analysis software.

One of the software tools that I use is their "CAM Pro for Cam Doctor" conversion program, which allows independent comparison analysis of any lobe against any other, and is a required tool for any owner of a Cam Doctor. Audie Technology no longer offers the DOS version of this program, but the current full version of CamPro for Windows can read Cam Doctor files.

See some EXAMPLE SCREEN SHOTS of the DOS version of CAM Pro for Cam Doctor program.

Other sophisticated cam measurement devices are available, ANDREWS PRODUCTS and ADCOLE are some of the more well known in the camshaft industry.
Specialty camshaft analysis software an be found at Performance Trends, Lotus Engineering Software, and Professor Blair & Associates for examples.

TOP OF PAGE