Ford's answers to the NHTSA 6.7 Investigation

[ricatic]

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 is over 20 pages long. There are some interesting statements contained in the documents. My favorite is the one where Ford says they buy the pump from Bosch as a "black box" and do no testing of the component. It is closely followed by the tantamount admission that the pump will not provide a long service life when exposed to the poor lubricity fuel found in the US. You will have to do the math using the sales versus failure tables for the US and Canadian trucks. Eye opening difference to say the least...

Regards

[coolbreeze01]

NewsW said:
"I think the whole thing is fuel lubed, not motor oil, and fuel is bled back to the fuel tank via a relief valve and also used as coolant."

I was wondering if fuel still circulated back to the tank. At what temperature? If warmer than air temp, could be a built-in moisture maker.......

[NewsW]

BenK wrote:

Always wondered, but haven't had the time nor inclination to noodle it
out on how those injector orifices keep from carbonizing/choking shut

Must have residual fuel being pushed back by the combustion process that
then is the 'plug' that keeps it clean enough for the next million cycles...

Or the injection of fresh fuel is sufficient to eject any deposit buildup.

In gasoline injectors, at much lower pressure, they can get clogged.

I don't know if there are coatings used on the diesel injectors.

DLC is used in the injector plunger for at least a decade --- definitely on the Siemens HEUI unit injectors, but I don't know about the Bosch piezo electrics.

I have not heard of widespread issues with the DLC unless it is referred to as injector stiction.

Siemens sold the diesel injection to Continental.

[NewsW]

blackeyed1 wrote:
I think I'll bring this stuff up to my high school buddy that used to be a GM engineer. He's like you guys that really get into high tech stuff. Most of this I haven't a clue what you are talking about but we all learn things by reading. 39 pages! Amazing!

Thanks for the message...

FYI, we don't have a clue what we are talking about either.

Just idle speculation and desk research.

If I only have $50m capital, $10m operating budget, a small staff of 20 highly qualified research engineers, and a project budget of $3m, plus the data from Bosch and Ford...

But I don't.

So it is just shooting the breeze.

😮

[BenK]

Ah...don't forget that the piezo valve being slammed shut by it's own coil springs are
assisted by back flow combustion chamber PSI via diesel fuel being burned !

{edit}....another Ah Ha !!!!

Always wondered, but haven't had the time nor inclination to noodle it
out on how those injector orifices keep from carbonizing/choking shut

Must have residual fuel being pushed back by the combustion process that
then is the 'plug' that keeps it clean enough for the next million cycles...

[NewsW]

BenK wrote:

Ha!!!!! I'll bet the screw/gear pump was removed as a cost cutting measure...

In fact... Bosch engineers were bragging about how CP 4 is cheaper to build.. and delivered higher pressures.

[blackeyed1]

I think I'll bring this stuff up to my high school buddy that used to be a GM engineer. He's like you guys that really get into high tech stuff. Most of this I haven't a clue what you are talking about but we all learn things by reading. 39 pages! Amazing!

[BenK]

Benk wrote:
snip...

Redundant and wonder why?

snip...

Ha!!!!! I'll bet the screw/gear pump was removed as a cost cutting measure...

[NewsW]

Think I have to do some digging on Bosch injector literature... to see what mysteries can we unravel.

[BenK]

NewsW wrote:
snip...

Rick -- show us the bearing ad seal material.. that is gonna be interesting.. real high tech.

Goodness, more thoughts on this new avenue

Organic amines...wonder if that also attacks and/or affects whatever
seal material(s) are in this system ?

That then leads to question if that might be the source of the mystery H2O...

Anyone pressure wash their diesel engine bay recently... 😞

[BenK]

That video doesn't do a good enough job of showing fluid flow, but it appears
to have both a piston and screw/gear pump.

Redundant and wonder why?

back on the CP4...there is still the slam when the flow is stopped by the injector
closure

The piezo only opens it against all of those springs, that then slam it shut
after the piezo's turn off. Key is how fast it slams shut to then understand if
there are pressure waves in there going back to the pump & one way valve

That is the function of a 'properly' designed accumulator to absorb and
nullify or reduce down to 'background noise'...

[NewsW]

BenK wrote:


How is that lob lubed? Assume fuel and then where does it come from and
it should have a return or relief back into the fuel system somewhere

Asking because the cam shaft is also lubed some how. Then ask what kind
of bearing is used? Is that lube under the same PSI as the incoming
fuel to the piston/chamber?

Am getting at whether there is a potential source of contamination from
that bearing and it's seal?

Rickatic need to post pics of his disassembled pump.

I think the whole thing is fuel lubed, not motor oil, and fuel is bled back to the fuel tank via a relief valve and also used as coolant.

Rick -- show us the bearing ad seal material.. that is gonna be interesting.. real high tech.

[NewsW]

If it is a shock generated by the closure of the valve -- then the accumulator / injector is not really part of the problem.

What if you took a look at the CP 3, supposely a more complex and expensive design, and see how it was made simpler in the CP 4.

We know the CP 3 is good, at least at lower pressures.

http://www.youtube.com/watch?v=bHWbnP2l37Y

CP 3 video


Does it look like the CP 3 have a gear pump ahead of the piston pump vs. the CP 4 that is the piston pump only????

[BenK]

Just as thought...it uses the fuel PSI to self shut along with a coil spring

That is where the shock wave is generated...when that valve shuts and since
via the fuel flow/PSI, directly linked or back into the fuel lines

Any have tossed the cam lob as the potential culprit. That is where
my initial thoughts were, but after learning how it works, of course not
there...but...a new one creeps in...

How is that lob lubed? Assume fuel and then where does it come from and
it should have a return or relief back into the fuel system somewhere

Asking because the cam shaft is also lubed some how. Then ask what kind
of bearing is used? Is that lube under the same PSI as the incoming
fuel to the piston/chamber?

Am getting at whether there is a potential source of contamination from
that bearing and it's seal?

[BenK]

Factored by cavitation, which creates dry/non-lube situations inside the chamber

[NewsW]

See if these videos shed light:

http://www.youtube.com/watch?v=HIok47p8zCw

Pump

http://www.youtube.com/watch?v=u-ZC1FaNDh0

Piezo injectors.

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More injectors electronics:

http://www.youtube.com/watch?v=Yb0lEWHHDE0