[Diy_efi] Greenfire claims
skishop69 at yahoo.com
Wed Jun 8 20:24:48 CDT 2005
Remind me to never post unless all of my facts are there! Seriously though, Adams points are solid. I' definitely not an expert on this but a lot of what was on the website seemed like political doubletalk as Adam pointed out. The flame front statement is the perfect example. It doesn't matter what kind of IC engine you've got, a single (or multiple) spark starts the flame front which rolls along on it's merry little way to complete combustion. Are they saying they've found a way to convert electrical current into fire bypassing the whole 'spark' scenario? ;)
Maybe they do actually work, but they just haven't figured out how. Be sure to share your results if you're 'lucky' enough to get a set Adam.
Adam Wade <espresso_doppio at yahoo.com> wrote:
Just for fun, let's analyze Greenfire's claims:
"Its technology creates a flame front instead of a
Hm. A single spark creates a flame front as well. It
just takes a moment to grow. This can be done by
advancing spark timing.
"and so it ignites fuel quickly, burns for longer"
This is contradictory. If the charge is ignited more
rapidly, how can the burn take longer?
"and more completely"
This begs the question of what constitutes a "complete
burn". If they are suggesting that they change more
of the fuel and oxygen into final post-combustion
components (those found after a catalytic converter),
I'm not sure how this could be possible. They claim
lower emissions AND better power, and a quick burn
will make slightly better power when the PPP is
maintained at its optimal point. However, the
difference based on several clustered sparks vs. a
single spark is very slight, and there is very little
impact on emissions (these effects are pretty
well-established by years of testing).
"A spark can only initiate a single small point of
ignition and so it always takes the same time to burn
the fuel and it only burns to the same extent."
This is demonstrably false. Burn speed depends on
both mixture and charge density, among other factors.
"Greenfire introduces flames to the combustion process
via small venturi passages. The flames' extent of
fuel ignition is greater than a spark.
This is conceptually different from a spark, so its
ability to burn more fuel is different and greater."
It's unclear what they are trying to claim here. Are
they saying they are projecting jets of flame that
travel faster than the growth of the flame kernel in a
normal SI engine? If so, I refer back to by bit above
about slight increases in power from increasing burn
rate slightly. Still, combustion is combustion.
And as far as "The flames' extent of fuel ignition is
greater than a spark."... What is the "extent of fuel
ignition"? I cannot understand what that means. A
spark generates a flame front, as mentioned above, so
once again there is no ultimate difference according
to their description, except that you need to run
slightly advanced spark timing with a point ignition
source vs. a 3D or multiple point ignition source(s).
"Greater control of burning occurs."
Burn is very well-controlled. If it was not, our
engines would not last very long at all. There is no
basis for claiming better "control" of the burn
(although the more rapid the burn, the less important
are the other factors affecting its burn rate, give or
"Catalytic converter does not need to work as hard."
This is truly amusing. The catalytic converter is
nothing but a device the chemically alters what passes
across its surface. It's the heat of the exhaust that
provides the motive force for the reactions involved.
The cat is not a muscle; it does not get tired, and if
it is clean and at operating temperature, it can only
be "overwhelmed" if the rate of gas flow through it is
far too high, and many pollutants are escaping its
vicinity without being catalyzed.
"makes alternate fuels more viable, as it also burns
these fuels more easily and cleanly."
I see no evidence to support this claim, and none is
Then we move on to their theoretical design if
building their device directly into the combustion
chamber surface (never mind how they will maintain
electrode integrity and spark gap over the life of the
engine, something they choose not to touch upon).
I'll skip their comments on changing the overall
cylinder head design, since the arguments there would
be long and tedious, and of little interest to most on
"Maximum chamber coverage at ignition - not just a
spark to trigger combustion."
Again, I have no idea what they mean by this. Perhaps
they are suggesting that there will be multiple
devices in each combustion chamber? Nearly the same
effect could be achieved with slightly advanced spark
timing and multiple spark plugs (as noted above).
"Pinpoint accuracy can mean greater efficiency"
What "pinpoint accuracy"? There is nothing on the
device the size of a pin point. There is no reason to
suspect the spark timing will be any more or less
precise than with a conventional spark plug.
"Stronger firing initiation is possible within the
Another statement which I cannot decipher. I have no
idea what "firing initiation" is. And since there are
supposedly no changes to the spark generating hardware
(except changing how the spark, once made, generates a
combustion event), there should be no difference in
the electrical demands and the actual measurable
waveforms in the system itself.
"Fire propagation (rate) and extent of propagation is
"Fire propagation"? By parenthesizing "rate"
afterward, they seem to be suggesting an increase in
burn rate. I covered that several times above.
"Extent of Propagation"? They seem to be suggesting
that for some reason a significant amount of fuel is
never burned during "normal" SI combustion, which is
not the case. As noted, slight gains will be seen
when there is a faster burn rate and all other factors
remain the same, but this has to do with the smaller
drop in CC volume achieved by more rapid combustion.
"Higher compression and IMEP are possible, even in
This is true, PROVIDED the engine is not knock limited
(i.e., timing must be retarded from MBT to prevent
detonation, as most car engines are today), and also
provided that spark timing is changed to suit the
faster flame front propagation.
"Greenfire is the only entity to reduce emissions in
I have a feeling the people who invented electronic
fuel injection, the O2 sensor, the two- and three-way
catalytic converters, air injection, stratified-charge
engines, and so on and so forth would be very
surprised to hear this claim...
Next they show their patent application, the most
topical sections of which are their illustrations, to
shows a single venturi basically grafted onto the end
of what appears to be a conventional spark plug (with
a full-circumference ground electrode and a rounded
rather than square-edged center electrode).
As noted by others, their "independent testing" simply
shows claimed results, with no indication who did what
tests, or their methodology.
And that's all that is on their website.
A web search turns up nothing but their website, a few
of their press releases, and some puzzling about the
product (with no user feedback) on a variety of
automotive chat boards.
I've emailed them about getting a set of plugs to
test. I'd really like to be surprised by these plugs
when doing actual testing, but I have significant
doubts about their effectiveness.
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