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
From that image, am guessing that the right side is the first to see fuel from
the pump.
Then goes over to the left side.
Or if both sides are evenly balanced with a direct feed from the
pump, better, but still not good without an accumulator
IMHO, using the common rail for both plenum and accumulator is asking for trouble
'if' an accumulator is warranted.
Even used as a plenum, poor design, the left side sees the run from the right side
to have some delay and/or drop in PSI.
Thanks for posting the info on injector shock. Confirmed some thoughts that
there are way too many pulsations inside the hydraulic system playing by themselves
and marrying with others.
Can one assume that some of those shock waves enter the fuel pump piston chamber
while the one way valve opens into the common rail feed tube?
Anyone know the characteristics of those piezo injectors? Am assuming that there
is little to no hysteresis with their open/close cycle...or am I all wet there?
Good that there is no return on this system, as think any return would just add
another layer of potential wrench in the frey
If/since no return, then it MUST have some sort of accumulator...otherwise that
piston pump would kill itself in short order pumping into a fixed volume chamber
with 'some' relief via injectors...but...it must not be, as then the PSI would
fluctuate too much.
The more I think about it, it has to have an accumulator or some compliant
reservoir (accumulator) somewhere...maybe they are using some rubber/synthetic
hose as the accumulator?
Anyone know the injector working PSI range? vs the common rail PSI range? This would provide limited and a guesstimation look at their
hysteresis. On that, how does the injector close?
Can one assume that the common rail/accumulator HAS TO HAVE HEAD ROOM OVER THE INJECTORS?
To keep this from going too oblique...this train of thought has to do with the
shock back-feeding to that one way valve and then the pump piston
Think that it is cavitation inside he pump piston chamber that creates bubbles
(either or both micro gaseous bubble, H2O micro droplet) that then tears apart
the softened DLC (via organic amines). That then has the DLC pit/flake/etc to
have the piston go metal on metal (those bubbles will have voids which has no
lube).
The injector/plenum/common-rail shock waves working on the one way valve only
exacerbate this or is an accelerating catalyst for this mess.
the pump.
Then goes over to the left side.
Or if both sides are evenly balanced with a direct feed from the
pump, better, but still not good without an accumulator
IMHO, using the common rail for both plenum and accumulator is asking for trouble
'if' an accumulator is warranted.
Even used as a plenum, poor design, the left side sees the run from the right side
to have some delay and/or drop in PSI.
Thanks for posting the info on injector shock. Confirmed some thoughts that
there are way too many pulsations inside the hydraulic system playing by themselves
and marrying with others.
Can one assume that some of those shock waves enter the fuel pump piston chamber
while the one way valve opens into the common rail feed tube?
- What does that do to the piston?
- The cam and follower?
- The PSI inside the piston chamber?
Anyone know the characteristics of those piezo injectors? Am assuming that there
is little to no hysteresis with their open/close cycle...or am I all wet there?
Good that there is no return on this system, as think any return would just add
another layer of potential wrench in the frey
If/since no return, then it MUST have some sort of accumulator...otherwise that
piston pump would kill itself in short order pumping into a fixed volume chamber
with 'some' relief via injectors...but...it must not be, as then the PSI would
fluctuate too much.
The more I think about it, it has to have an accumulator or some compliant
reservoir (accumulator) somewhere...maybe they are using some rubber/synthetic
hose as the accumulator?
Anyone know the injector working PSI range? vs the common rail PSI range? This would provide limited and a guesstimation look at their
hysteresis. On that, how does the injector close?
Can one assume that the common rail/accumulator HAS TO HAVE HEAD ROOM OVER THE INJECTORS?
To keep this from going too oblique...this train of thought has to do with the
shock back-feeding to that one way valve and then the pump piston
Think that it is cavitation inside he pump piston chamber that creates bubbles
(either or both micro gaseous bubble, H2O micro droplet) that then tears apart
the softened DLC (via organic amines). That then has the DLC pit/flake/etc to
have the piston go metal on metal (those bubbles will have voids which has no
lube).
The injector/plenum/common-rail shock waves working on the one way valve only
exacerbate this or is an accelerating catalyst for this mess.
