Quote:
Originally Posted by RustyLugNut
Modern engines burn pretty much all the fuel dispensed, within the power stroke. Simply vaporizing the fuel before it enters the engine does not gain you any additional efficiency unless your fuel system was primitive.
However, as mentioned in another Ecomodder Thread, HOW the fuel burns has tremendous room for improvement. The work that people such as Ivey and pfgPro have done show that there is room to improve thermal efficiency via the addition of energy to the fuel mix. Heating is just one variable. Tumble and swirl is another. Addition of oxidative or reactive elements or compounds is worth a closer look.
I mentioned the work by Transonic Combustion Technology because it does NOT make sense to most people on a simple precursory viewing. Their advertised gains are valid, however. Injection of gasoline heated to 300 degrees C while at 8000 psi puts it in a super-critical state whereas the fluid/gas has unusually high diffusion rate (something like three orders of magnitude greater than standard state) resulting in deep penetration into the combustion chamber BEFORE auto ignition can occur. When auto ignition does occur, the mixture is fully gaseous and HCCI (homogeneous charge compression ignition) comes into play. Their engine was tested by the Society of Automobile Engineers in Detroit and the fuel efficiency gains as well as the emission claims were validated and awards were given thus this technology is not snake oil. The engine ran as a throttle-less engine. Mazda's HCCI capable SkyActive engine can only use HCCI in a narrow band. The beauty of Transonic's Technology is the ability to run HCCI in the ENTIRE power band! The problem of their technology they were unable to overcome was that: a few psi extra pressure or a few degrees extra temperature and carbon would form. And not just soft fluffy carbon, but something akin to industrial diamonds. You can imagine the effect on injector longevity.
All this being said, the work of Ivey and pfgPro is sneaking up on the fabled Smokey Yunick Adiabatic Engine. From everything I can glean, his engine was on the threshold of HCCI combustion but, not quite. I think pfgPro's engine is leveraging the above discussed principles to approach the HCCI regime creating a faster burn than normal resulting in far less need for ignition lead time and wasted burn in the lagging portion of the power stroke. This is especially evident in the fact that when he is running 30:1 air/fuel ratios (AFR), his ignition lead is reasonable and his combustion stability is good.
Smokey used carburetors and eschewed electronics. pfgPro is leveraging modern electronic controls. We can see how advantageous that is. I think we can create a near HCCI engine that runs in a much broader range than Mazda's SkyActive system.
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I see. Very interesting. And yes, I see what you're saying now.
Lean burn is one advantage that other gaseous engines have. I've heard of running 30:1 or leaner in propane and natural gas engines, and even way leaner in hydrogen engines. At those levels emissions almost dissapear as it can't get hot enough for NOx to form, although getting rid of any NOx in the exhaust becomes much more dificult with so much oxygen. The point is it's something that's obviously been proven.
Same with HCCI.
And yes, better ways of burning fuel is where it's at. There have been big improvements in intake design over the years that focus more on fuel atomization and trying to keep fuel from deatomizing.
I'm just trying to keep everyone's expectations in check. No offense to the OP, but some comments here seem to me to be overly optomistic and I might go a bit too far in trying to keep expectations in check.
Quote:
Originally Posted by racprops
And the only other classic idea is Gasoline VAPOR.
Claims and reports of 100MPG are all over the place.
Fish Carb, Tom Ogal's system, etc.
I will see if I can do a proof of concept device.
Rich
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