Ford's answers to the NHTSA 6.7 Investigation
There was a request for a link to Ford's answer's to the NHTSA investigation posted on a previous thread, since closed. Here is the link: Ford's NHTSA Answers to the 6.7 investigation This PDF i...
Forum Discussion
Excellent point on lubricity, viscosity and PSI at the cam/follower
Agree that using diesel as a lube is a huge mistake, especially in light of the PSI's
Exotic coatings is well known in the gear industry. From case hardening, to nitriding,
to exotic coating and the biggie...designing the lube film to act as the barrier
to metal on metal contact
In theory, our diff gear boxes are designed to have the gear faces never go metal
to metal. Why the viscosity is so high both for the film strength and the heat
generated that reduces viscosity.
They do go metal to metal often from shock loads and plain over loading where
the heat reduces the viscosity and the forces squeezes the lube out
When gear tooth faces are over stressed, it work hardens the surface, then the
surface micro fractures to either crumble (pitting) or flake off.
Why there are metal particle, however small, always found during a diff fluid
change. Why there are magnets (in most) to capture the larger particles and most
of the smaller particles
There materials explaining this is numerous and we should take a look to see
if there is anything in reference to a roller.
On that, anyone know if there is a roller that has needles are it's bearing?
Or hopefully not, a journal bearing for that roller?
Staying on lubricity, how tightly tolerance'd are the lube attributes withing
the diesel fuel specifications? Think there is a new Ah Ha there Niner...good
point you outed
Then hypothesize that there might be chemical interaction within the diesel
itself (the additives that the OEMs employ) to the additives that the owners
toss in there.
Add some heat and passivisation to this brew and what do you have?...betcha
lost lubricity to some level
Oh, then organic amines...how the heck does that play in the now witches brew?
My experience with exotic coatings says that the coatings solve frictional issues
but DOES NOT solve base material issues. Meaning PSI elastic working of
the cam surface.
That is where I think the Bosch engineers 'think' they have solved the cam
follower PSI issue on the cam...an exotic coating.
Yes solves the frictional issue, but in no way do I see even addressing the
overall issue of strength of materials. That goes back to reducing the PSI
and we have gone over that several times (form factor must be increased...or
change the architecture)
To me, Bosch is missing that talent with my guess, mistaken ID of the true
issue(s). Silly, as they most likely do have that talent, but not on this team
Then that 'thrust' (I used shock) moment is transmitted to the shaft and the
bearing, which has an aluminum housing, which most likely is the material that
bears these forces.
What kind of shaft bearing? What kind of seal? Then what kind of lubrication
(type, viscosity, etc) does that bearings specification require? To then compare
it to the diesel lubricity specification (and how tightly tolerance'd) along
with whatever additives are in that brew
Think that if there is ANY movement at the bearing, there is a cascading
effect up stream to the cam follower, therefore the piston.
On that, with this kind of 'thrust'/'shock' loading...if the sizing/type/etc
of the shaft bearing doesn't have enough margin, it will wear to become loosey
goosey enough to create havoc on the follower/piston/cylinder
That would in my guess, have the follower leave or lose contact with the cam during
the intake stroke. To then bang back on during the compression stroke. To create
an even larger PSI thrust/shock loading between the cam and follower's bearing
This scenario needs access to worn but not broken, yet, parts for examination
and measurement
{edit}....a new variation...if there should be a cavitation event
in the cylinder after that one way valve slams shut...would that then
lift the piston cam follower off the cam?
To then slam back into the cam during the compression stroke?
Anyone know if the piston/follower are positively captured together?
There is a spring in there, but is that spring sized in anticipation
of a cavitation event?
Can it be designed to manage cavitation? How? Can't get my noodle
around that at this moment...
On the higher pressure vs emissions related combustion vs going back to the old
pump. Noodling if they can make up for the lost efficiency of higher PSI with
some exhaust filtration/catalyst/etc.
Another very good one by Niner (De Laval) and had forgotten about that. Assume
the same/similar effect at a lower pressure, albeit less efficient atomization
I'm convinced that the CP3 pump is the reason cavitation is NOT an issue. It's
pressure is also conducive for cavitation, but there has not been any indication
that cavitation was an issue
With the gear pump feeding the piston pump, there is a constant, positive flow
to the piston/cylinder. The pressure drop would have been much, much less
The only potential cavitation is during the piston compression stroke where it
out ran the gear pump's GPH, as that is how it 'should' work between these
two types of pumps
On timing...there are issues with cogged belt drive. Stretch and the change
of timing during that stretch and then catch up. Ditto during pedal release
Just interesting indication that they either confirmed (must be) or 'thought'
there were injector shock waves.
Again, accumulator of some sort would have been a better solution than timing
There are many other extremely high PSI/BAR systems using fluids to cut metal,
concrete, etc. But they are constant flow vs ICE pulsations vs RPM
Wonder what types of pumps they employ?
Am now noodling whether H2O is truly a culprit. Think plain strength of materials
at play, or the lack of understanding what they really have going on in there.
{edit}.....maybe still in the fray but not as significant directly
Lubricity affected by H2O is one, oxiding of the pump innards still
there.
Agree that using diesel as a lube is a huge mistake, especially in light of the PSI's
Exotic coatings is well known in the gear industry. From case hardening, to nitriding,
to exotic coating and the biggie...designing the lube film to act as the barrier
to metal on metal contact
In theory, our diff gear boxes are designed to have the gear faces never go metal
to metal. Why the viscosity is so high both for the film strength and the heat
generated that reduces viscosity.
They do go metal to metal often from shock loads and plain over loading where
the heat reduces the viscosity and the forces squeezes the lube out
When gear tooth faces are over stressed, it work hardens the surface, then the
surface micro fractures to either crumble (pitting) or flake off.
Why there are metal particle, however small, always found during a diff fluid
change. Why there are magnets (in most) to capture the larger particles and most
of the smaller particles
There materials explaining this is numerous and we should take a look to see
if there is anything in reference to a roller.
On that, anyone know if there is a roller that has needles are it's bearing?
Or hopefully not, a journal bearing for that roller?
Staying on lubricity, how tightly tolerance'd are the lube attributes withing
the diesel fuel specifications? Think there is a new Ah Ha there Niner...good
point you outed
Then hypothesize that there might be chemical interaction within the diesel
itself (the additives that the OEMs employ) to the additives that the owners
toss in there.
Add some heat and passivisation to this brew and what do you have?...betcha
lost lubricity to some level
Oh, then organic amines...how the heck does that play in the now witches brew?
My experience with exotic coatings says that the coatings solve frictional issues
but DOES NOT solve base material issues. Meaning PSI elastic working of
the cam surface.
That is where I think the Bosch engineers 'think' they have solved the cam
follower PSI issue on the cam...an exotic coating.
Yes solves the frictional issue, but in no way do I see even addressing the
overall issue of strength of materials. That goes back to reducing the PSI
and we have gone over that several times (form factor must be increased...or
change the architecture)
To me, Bosch is missing that talent with my guess, mistaken ID of the true
issue(s). Silly, as they most likely do have that talent, but not on this team
Then that 'thrust' (I used shock) moment is transmitted to the shaft and the
bearing, which has an aluminum housing, which most likely is the material that
bears these forces.
What kind of shaft bearing? What kind of seal? Then what kind of lubrication
(type, viscosity, etc) does that bearings specification require? To then compare
it to the diesel lubricity specification (and how tightly tolerance'd) along
with whatever additives are in that brew
Think that if there is ANY movement at the bearing, there is a cascading
effect up stream to the cam follower, therefore the piston.
On that, with this kind of 'thrust'/'shock' loading...if the sizing/type/etc
of the shaft bearing doesn't have enough margin, it will wear to become loosey
goosey enough to create havoc on the follower/piston/cylinder
That would in my guess, have the follower leave or lose contact with the cam during
the intake stroke. To then bang back on during the compression stroke. To create
an even larger PSI thrust/shock loading between the cam and follower's bearing
This scenario needs access to worn but not broken, yet, parts for examination
and measurement
{edit}....a new variation...if there should be a cavitation event
in the cylinder after that one way valve slams shut...would that then
lift the piston cam follower off the cam?
To then slam back into the cam during the compression stroke?
Anyone know if the piston/follower are positively captured together?
There is a spring in there, but is that spring sized in anticipation
of a cavitation event?
Can it be designed to manage cavitation? How? Can't get my noodle
around that at this moment...
On the higher pressure vs emissions related combustion vs going back to the old
pump. Noodling if they can make up for the lost efficiency of higher PSI with
some exhaust filtration/catalyst/etc.
Another very good one by Niner (De Laval) and had forgotten about that. Assume
the same/similar effect at a lower pressure, albeit less efficient atomization
I'm convinced that the CP3 pump is the reason cavitation is NOT an issue. It's
pressure is also conducive for cavitation, but there has not been any indication
that cavitation was an issue
With the gear pump feeding the piston pump, there is a constant, positive flow
to the piston/cylinder. The pressure drop would have been much, much less
The only potential cavitation is during the piston compression stroke where it
out ran the gear pump's GPH, as that is how it 'should' work between these
two types of pumps
On timing...there are issues with cogged belt drive. Stretch and the change
of timing during that stretch and then catch up. Ditto during pedal release
Just interesting indication that they either confirmed (must be) or 'thought'
there were injector shock waves.
Again, accumulator of some sort would have been a better solution than timing
There are many other extremely high PSI/BAR systems using fluids to cut metal,
concrete, etc. But they are constant flow vs ICE pulsations vs RPM
Wonder what types of pumps they employ?
Am now noodling whether H2O is truly a culprit. Think plain strength of materials
at play, or the lack of understanding what they really have going on in there.
{edit}.....maybe still in the fray but not as significant directly
Lubricity affected by H2O is one, oxiding of the pump innards still
there.
