Ford's answers to the NHTSA 6.7 Investigation

BenK wrote:


Sounds like they should have used Tungsten Disulphide. Used to have
my stuff plated by Diversified Dry Lube out of Tulsa OK, but they
no longer there

Cold process that plated 4-5 micron's and did NOT change the surface
finish. IIRC, inert and FDA approved (food grade surface), non-stick,
very low co-efficient of friction and very low cost. Really wanted to
coat everything inside one of my engines, but never got around to it


Again, ask why DLC is needed and what is the problem being solved?
Is it the piston and cylinder wall? Is it the cam and follower? or ???

Tungsten disulfide will not have worked. The number of cycles and the stress the surfaces are under mean it took a coating with durability and slipperiness that far exceed Tungsten disulfide.

DLC is needed because it offered unimaginable properties relative to the old coatings.

I know for sure it is on the cam and contact surface, suspect it is on the piston and sidewalls, but have no independent confirmation.

A critical issue is surface prep --- as whatever defects tend to be faithfully replicated.

In the old days, before you coated, a part is blue printed.

AFAIK, that is not good enough for the tolerances in the CP4 series, where tolerances require surfaces to be extremely tight in terms of spec and smoothness, etc.

What I do not know:


Is the part even machined to "round" or "flat" or is there a bag of tricks involved at the level of microns?

Hypothetically, the piston cylinder could have a face that is machined ever so slightly from flat at the cam end, so it turns ever so slightly to equalize wear on the round bore.

Or, the cam lobe can be ever so slightly inclined, to force the shaft back toward a pressure seal.

Many of these things are possible, but without knowing the engineering data, we can only speculate --- very hard to see this kind of tweaks from sample reverse engineering.