It looks like the flat tappet cam failure bug is re-appearing after being dormant for the past few years.  It also appears that nobody is getting a satisfactory answer from the cam representatives as to why this occurring.  We thought for some time  it was the oil's fault, but based on Barry's recent experience this may no longer be true.

I would like to take another approach to this issue.  I am willing to section, polish and evaluate cams to try to evaluate what is different from the 'factory' of old:

• Visually measuring the hardness depth based on the sectioned cam lobes
• Measuring the hardness level with an indention Rockwell C method, and non-contact.  This would be done on the OD of a cam lobe, and at various locations on a sectioned lobe from OD to center
• Visually measuring the grain structure
• Verifying the cam material properties.  What are the constituents, and is there more or less of one alloying element than another when compared to the factory cams?

If anyone has a factory cam print (John Vermeersch or Dave Shoe maybe, I dont think I have a factory print in my copies) that we can compare back to, it may have hardness or basic material requirements listed.  I know the hardness requirements were listed on the SOHC rocker arms.

Would anyone be willing to participate?  All I would need from you besides a failed cam (and the lifter on the failed cam) would be:
 

• Miles until failure
• Spring pressure
• Cam manufacturer
• Day, month, year of when cam was manufactured (that may be listed in a code on the cam)

I estimate that I'll need a total of 6 failed cams.  I will section the failed lobe and two 'un-failed' lobes per cam to see if there is variation from lobe to lobe on a single cam, plus variations between cams overall.  I will also section two factory cams out of junkers at the local Pick N Pull.

If people are interested it will take me 4-5 months of weekends of sectioning and polishing to get the specimens ready and tested and report findings 

Cheers,
Joe