Ford's answers to the NHTSA 6.7 Investigation

BenK wrote:
Rick, I'd like you to check if the piston bottom
is captured....if not, then ckeck if it is banged up

...Via smartphone...excuess fat finger typos

I'm not following you here, are you referencing the piston being captured by the spring? Bosch has claimed to NHTSA that "the spring tension on the piston makes the design revolutionary, and self aligning" I think they were correct on the revolution part only... that piston can indeed revolve inside the bore, and when it does,, due to spring harmonics at various RPMS, it can induce the piston to rotate both directions, just by modifying the rpms. Anyone that has seen a spring and a valve at various rpms on a cut open head on a motorcycle can comfirm it.

This rotation, in turn, destroys the alignment the roller has to maintain with the cam, to stay squared up to the cam surface with the roller follower. There have been plenty of instances where this type of failure has been observed, the cam roller 90 degrees out of alignment, no longer rolling, instead grinding on the cam surface.

At times, I don't know what Bosch was thinking, every roller cam I've ever seen had a rocker arm for alignment that the roller was attached to, and had motor oil as a bath for lubrication, not diesel fuel with it's stinking low Centistoke viscosity of 1.5, versus motor oil, with additives for barrier protections from 12 to 15 centistokes.

But then, what do I know... just basing it on history. for the life of me, I don't see why Bosch couldn't make the bore steel, the piston aluminum, and "D" shaped for alignment purposes and forgo running fuel as lubrication, run motor oil off the engine's oil pan. The piston just needs to provide alignment for the 10mm plunger and bore above it, not seal effectively, nor worry about blow by. There are better ways to keep that plunger in alignment with it's bore than this method.... The merry go round style cam with 4 rollers was the epitome of reliable in the old VE 37 systems VW ran.