PMK
Active member
Actually you can do aluminum, just a slightly different process with dye and a powder material.
Yes, I believe a diamond hone is all that can be used, and it is very thin and could require a trip to Millenium. I think the main problem is not knowing the extent of damage and putting a lot of labor and money into it and still having problems. To break a cam main takes some energy! If it were me I would inspect everything and replace as necessary and freshen the rest. But that's me! Years of racing and no time to do over leads me in that direction. I wish the OP the best outcome in his project.
Many people incorrectly believe that aluminum can be Magnafluxed. Magnaflux is a company name, associated with magnetic particle inspection, a process where a ferro magnetic item is magnetized and iron fillings, either dry or in a fluid suspension, and either visible in white light via the naked eye, or fluorescent requiring a black light to see indications.
Magnaflux, the company also produces the process you indicated known as liquid penetrant inspection. Liquid penetrant process can also be accomplished with products visible in white light, or Zyglo which requires a black light. Zyglo penetrant are available in various sensitivities and methods to remove residual penetrant. The application of the powder, done correctly enhances visibility. Incorrectly done it will mask indication.
A much better inspection method for non ferrous item, when the shape permits is eddy current inspection. Eddy current is able to detect subsurface defects and more.
Each method has limitations, and requires a qualified, and ideally trained person accomplishing the inspection.