Ford's answers to the NHTSA 6.7 Investigation

Not a fluids guy either, but willing to give it a go based on my controls and
process controls background...along with portions of that with hydraulic metal
rolling mill rams

Hope the controls, process controls and automation will suffice in figuring out
the sequencing...of course lots of help from you guys

Mainly, for now, labeling that cross section Niner posted

One big old red flag to me was seeing that metering piston 'there'. Makes no sense
as any kind of metering should be on the output side of something that can
blow the snot out of most anything

It should be either before, in or after the accumulator...and...meter it via
return line to the tank.

This where got the idea that the engineers were told 'no accumulator' and they
tried to side step it with wacky routing and 'metering', to create a vacuum
situation, some times, that then creates conditions to rip the softened DLC
to then create debris

Also, that the crank shaft/cam cavity is poorly done, if that cross section
is accurate.

To me, it's just a flow diagram with lots of oblique lines to bubble/functions
on another page. Just follow it to that end, and if more oblique lines, just
follow them too till that ends...etc...and always come back to the original
function(s)

An example...take the crank shaft/cam cavity.

Can see how they use the fuel as lube and coolant.

Maybe depended on the pumping or flow action of both the linear movement of the
follower (piston like) and the rotation of the cam, which acts like two paddles

The whole idea in that cavity is to lube and cool.

That then says fresh fluid and lots of it. As they decided to use an exotic
coating that is very expensive. Forensics says that, as cost is key to decisions
for that kind of solution.

Then one question...would they still need DLC if the flow of coolant and lube
'good enough' ???

That pumping/flow also has such in-efficiencies that I think the fluid does not
flow out much at all. Just re-cycles within the cavity to get hotter and hotter
all along possibly generating debris

That is because the intake port and exhaust port are right next to each other
(why need to know if this cross section is accurate).

There will be 'some' new fluid pulled or paddled into that re-cycled fluid area
to mix some fresh

The exhaust port has a relief valve/return to the tank

Curious why they have a 3rd port and continue to think of it as a tuning or
balance mechanism, but really don't know for now. Most likely in conjunction
with the metering valve...more later on that

Worst part of this cavity is that the area where the follower spring bottoms
is a dead end and can't see any way for fluid in there to ever get outta there.

Unless the piston to follower area has a hole of some sort to allow fluid to
flow down from there when the follower moves up/down

I would have put the exhaust or intake near where the spring bottoms and the other
port as far away as possible so that the flow to the injectors would have fluid
exchange the whole cavity all the time...not as I see it now where it pretty much
re-cycled with 'some' fresh mixed

Back to the metering valve and the exhaust port's relief valve that I'm assuming
goes back to the tank...why is there a relief valve here?

Is there a pre-pump that needs this when the metering piston is actuated?

This is where I think deceleration or EB comes in. They don't fuel during that,
or greatly diminish the fuel rates, right?

Since this pump is cog belt driven and no clutch, it will continue to pump no
matter what is going on and that the pulley is still being driven, right?

But since the pump is still driven and the piston continues to pump when the
metering piston pinches off any fuel supply, the piston/cylinder go vacuum, right?

That is where I think cavitation happens the most and during deceleration and/or EB, in the cylinder/piston NOT in the cam cavity

Now to the next one way valve at the top of the piston/cylinder. Okay, see that
and again, not the stuff before it

Now you are in a single rotation intake, exhaust of the piston working on the
two one way valves of the cylinder. Good, that is what it should be

But the piston does NOT seem to captured to the follower.

If captured it would create a vacuum in the cylinder via the two one way valves

If it is NOT, then the piston would not go down, but then how does it continually
go down during normal op?

Could that be the issue? When the follower changes direction and then bangs into
the bottom of the piston?

Over time and with enough 'metered' cycles creating bangs, it does cause some
debris in the back water, stagnant cam cavity?

Is that where the debris comes from?

Just some initiate thoughts and will noodle it some more tomorrow. Especially
if someone can spot the acronyms to the component/area.