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

[NewsW]

Biodiesel is the real witches brew.

Large number of makers, little quality control.

Methanol, soap, catalysts, water, etc. can be used in production, as with a whole lot of wash chemicals:



See wet and dry wash:

The industry is answering the call by implementing programs designed to enhance fuel quality. BQ-9000 is a voluntary quality assurance program that includes procedures for fuel storage, handling and management with the goal of ensuring fuel quality throughout the biodiesel distribution system. Impure fuel may degrade engine oil, corrode fuel injectors with water and catalyst, block fuel injectors with soaps and glycerin, and cause seal failure due to methanol.

There are two generally accepted methods to filter and purify biodiesel: wet and dry washing. The more traditional wet washing method is widely used to remove excess contaminants and leftover production chemicals from biodiesel. In this process a fine water mist is sprayed over the fuel. The fuel's impurities are removed as the water settles to the bottom of the tank. However, the inclusion of additional water to the process offers many disadvantages, including increased cost and production time.

Conversely, dry washing replaces water with a magnesium silicate powder to neutralize fluid contaminants. An example is The Dallas Group of America Inc.'s trademarked Magnesol XL. The dry wash process offers myriad advantages over the wet wash system and is quickly becoming the method of choice among biodiesel producers for several reasons.

http://www.biodieselmagazine.com/articles/1918/a-dry-wash-approach-to-biodiesel-purification/



http://www.answers-to-your-biodiesel-questions.com/biodiesel-chemicals.html



In theory, the nasty stuff, like methanol, water, is suppose to be out of the finished product.

But --- we know quality control is often indifferent --- even before you talk to home brewers.

Then there is the issue of storage.

Biodiesel is much less stable in storage (this was mentioned in the 2009 joint statement by the equipment people.

So even if the fuel is great, store it too long, improperly, or have water ingress into storage tanks, and it can screw up real fast.

Worse, it can be an emulsion --- making it hard to detect until it is in your tank.


http://utahbiodieselsupply.com/blog/archives/373

[BenK]

An new one...alcohol and the winter blend...factored by the ambient conditions that
will exacerbate condensing conditions

Again, I'm not a diesel guy so ask is there and if so, how much alcohol in
diesel fuel? Does diesel fuel have a summer and winter blend? Which one has
the alcohol, again if it does contain alcohol. Plus any emulsification
between the alcohol, diesel and H2O


Does the alcohol some how exacerbate amines some how? Gads, this is constantly
leading me back to 'must' read that organic amines article

[NewsW]

As I understand it, water blocking membranes work with rejecting water (high surface tension) vs. fuel (low surface tension).

High enough pressure, and it will get through.

Don't know much about emulsion behavior ---- that is a part of chemical engineering that is covered wall to wall in trade secrets.

[BenK]

To that PM, answer here in case others are wondering...

This type of discussion is key to a good design and part the CDR's mentioned way
back at the beginning of this or the thread that got closed.

What meant by throwing rocks at the design till either the rocks bounced off or
the issue was acceptable to management (notice I didn't say engineering, but management
aka...bean counters)

[NewsW]

VW filters... do they have a water block membrane?

GM?

Ford?

Need some help here from our peanut gallery!

[BenK]

Thought so, then ask what is the common ambient conditions for the failures
to date?

If they are all in same/similar, another nail on the lid

By elimination, I've or my view is that the issue is with this pump
alone. Whether tiny car to full sized truck.

That then leads to cavitation as the main common attribute. Bet all
in potentially very cold ambient that can cool the tank quickly

Then why cavitation is an issue. Think combo of amines softening and/or
affecting the bonding tension to have it come apart during cavitation
to then both create debris and exposed metal on metal....to both create
more debris and lost co-efficient of friction...to...then destroy itself
to create even more debris

Does that membrane filter have a pressure threshold ? Then ask what
is the PSI's (tolerance) at that membrane? Also, it's efficiency
(percent blocked vs passed...then at what PSI's/concentrations/saturation's/etc)

Again, this seems to me to lead back to cavitation and HOW2 manage
or eliminate cavitation

[NewsW]

Fuel, by the very nature of going through high compression, is going to heat up even before it carries away heat from the pump.

Note --- remember Bosch patent to isolate pump from engine to reduce heat transfer?


If you heat up the fuel in the tank via the return hose, it will tend to become hydroscopic and whatever moisture in the tank that is separated will diffuse / be absorbed into the fuel up to the maximum non-emulsified water capacity of the fluid for that temperature.

When it cools down, it will either lose the moisture by letting it drop out, or more likely, become a super-saturated solution that can turn into a emulsion with some shaking / vibration.

That can create an emulsification that may not be filtered out.

Need to know whether a water blocking membrane (usually a polymer) will block water in emulsion vs. water.

Is the Ford filter equipped with a water blocking membrane?

GM?

[BenK]

H2O is known bad for non-plated ferrous components. Injectors (gasser) are known
to have problems with H2O, but don't know if diesel does too

But haven't heard anyone mention that, to toss the injectors as an issue with H20

The pump surfaces are DLC plated, but don't know if every last square inch is.
Does anyone know and then ask if there is any data on corrosion of those non-plated
areas/components within the pump?

Am trying to find the path the OEMs are hanging their hats on in regards to H2O
in the system

Corrosion is what am guessing they are referring to

Now the DLC and organic amines coming apart (another assumption that the OEMs
are saying) due to H20, but basically 'used' to know that diamond is very stable
and non-reactive.

Add organic amines, but no data that I'm aware of (dang, just have to find time
to read that article)

Add in cavitation, which I'm now leaning big time towards, as the accelerating
catalyst to all of this.

Then go back to a different type of pump that would NOT have such a high cavitation
potential. A gear pump would be my choice, but know that some sealed impeller
advertised PSI's in that range (very expensive and I have no other knowledge of
how well they live to their spec's).

Which then says there is a need to just replace the piston pump with
a gear pump with everything else the exact same to both remove the
piston as the culprit and/or say cavitation is the culprit

More later when have more time to noodle this...very intriguing !!!

[BenK]

Forgot to comment on that Ford patent covering cooling the returned fuel....

Another indicator that there is a moisture issue (condensation) in the fuel tank.

Maybe emulsified H2O in the brew and will need to noodle how that witches brew
behaves with warm/hot returned fluids into a cooler (how much cooler?)
pool of fuel.

Then the various additives and their interplay with the base fuel

Is this a good assumption that the heated fuel returned has any H2O excised
during whatever goes on 'up there' ?

now that leads to vacuum in the pump shaft/cam/etc cavity. If there is, is it
pulling in external stuff via the bearing seal?

Then if it does, it matters where that cam cavity lube/fuel goes next. If into
the HIGH PSI piston, to then see high vacuum to be exposed to cavitation, or if
it goes back to the tank, then is it laden with some level of H2O and/or contaminates ?

Noticed that all this revolves around H2O and possible contaminates exposed to
cavitation

How does that sound? Make any sense?

[BenK]

durallymax wrote:
snip...

The CP4 pump is timed so that its pulses match up with injection events.

A pressure regulator is still mounted on the pump but an additional one was added to control how much fuel is bled off into the return system from the high pressure system. Essentially replacing the fuel pressure relief valve.
snip...

Was going to ask what 'timing' meant, but this solves that and goes
to both confirm and tell-tale that they are aware of the pressure waves
we have been discussing

BUT how can ONE pump (single or even twin piston) be timed with
8 injectors? Then the secondary/tertiary/etc harmonics?...or are they
so low as to be noise?

Is there a sensor on the pump shaft vs the ECU or whatever is controlling
the injection system to allow them to sync? AKA...cam sensor for
ignition control


My controls DB hairs raised reading that there are *TWO* regulators
and/or relief valves to the return?!?!?

A huge tell-tale that they had a problem, chased it and solved it to
some level of confidence with the addition of another set of regulators/valves

Not good engineering, IMHO...worse if there is a 3rd set.

Marry that with the open question of whether there is/are any plenum/accumulator

That deals with pressure waves backfeeding to the piston chamber

Back to the piston chamber...am convinced there is cavitation issue(s)

Back to the lube and chamber for the shaft/cam/lifter and the shaft
bearing (it should be needle and hope large enough, as have seen too
many go too small dia needles) and the shaft seal.

Think a multitude of issues that are multiplexing.

H2O intrusion from the fuel (both raw H2O and emulsified) and now think
one mystery solved...must be or highly likely the pump shaft bearing
seal

Where does the pump shaft/cam/bearing lube go to after lubing that area?

Does it go back to the tank via the return line? Or becomes directly
the next intake for the piston?

Just have to find time to read up that article NewsW sent me on organic amines.

[NewsW]

Bosch piezo electric injectors

http://www.youtube.com/watch?v=ftchx1TDNJo&feature=relmfu




http://www.youtube.com/watch?v=cIkMtnd3LGQ&feature=relmfu

Diesel Fuel Pressure Limiter Operation


http://www.youtube.com/watch?v=niYW9pkPCH4&feature=relmfu

Diesel Pressure Sensor Testing

http://www.youtube.com/watch?NR=1&feature=fvwp&v=85IP8eY1nXY

Diesel Piezoelectric Injector Driver Circuit

http://www.youtube.com/watch?v=fPB5_9o11tI&feature=relmfu


http://www.youtube.com/watch?v=67GSNUR7eqM

[durallymax]

Below are some links to the LML fuel system that Henry posted up.

The Piezo injectors are fired from 160-240v @20amps according to the GM documents. Thats a lot of juice and is why you see the orange harnesses now on the duramax.

There is also a valve used to keep pressure in the return system which is supposed to aid in firing the injectors.

The CP4 pump is timed so that its pulses match up with injection events.

A pressure regulator is still mounted on the pump but an additional one was added to control how much fuel is bled off into the return system from the high pressure system. Essentially replacing the fuel pressure relief valve.


Fuel Routing

parts listing

[NewsW]

coolbreeze01 wrote:
Lest we forget.........Pinto Fires

That goes into my bin with the following:


http://en.wikipedia.org/wiki/Peloponnesian_War

[coolbreeze01]

Lest we forget.........Pinto Fires

[ricatic]

Ford says 5yr/100000 miles on the engine...yeah...right