Possible new rotary engine breakthrough?
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12-03-12, 08:50 PM
#9
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12-03-12, 09:10 PM
#11
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Cross post:
The thing is that ignition is slightly retarted and the rotar will not start spinning hte other direction.
this guy makes it seem like the rotor spins on a single axis in the center. It does not . the whole rotor moves around in a circular axis with the eccentric shaft. That is why the ignition of the rotors is different from the shaft speed. the rotors spin SLOWER than the shaft.
thus the rotor is moving laterally (to the left in his example) and does not benefit from direction combustion.
Hope that makes sense
I think Mazda solved the Spark plug thing as well. The trailing plug is TINY and wont leak past the seal. The leading plug wont lose any compression because there is pressure coming BACK from hte previous combustion.
this guy makes it seem like the rotor spins on a single axis in the center. It does not . the whole rotor moves around in a circular axis with the eccentric shaft. That is why the ignition of the rotors is different from the shaft speed. the rotors spin SLOWER than the shaft.
thus the rotor is moving laterally (to the left in his example) and does not benefit from direction combustion.
Hope that makes sense
I think Mazda solved the Spark plug thing as well. The trailing plug is TINY and wont leak past the seal. The leading plug wont lose any compression because there is pressure coming BACK from hte previous combustion.
12-03-12, 09:55 PM
#12
Mazda and NSU/Audi have been studying this from basically day 1. They, for all intents and purposes, invented this engine.
If the plug holes are too small, you will have poor flame front propagation. This is such a fundamental geometric aspect of the rotary engine that you can bet every combination has been investigated with existing architecture. Now, if Mazda does adopt rumored and patented exotic ignition technology, all bets are off. They patented plasma jet ignition and have experimented with prechamber systems. There have also been rumors of laser ignition.
There's all sorts of strange wankel rotary designs that have been used in experimental engines or in low production applications (single rotor air cooled single spark plug small engines).
If the plug holes are too small, you will have poor flame front propagation. This is such a fundamental geometric aspect of the rotary engine that you can bet every combination has been investigated with existing architecture. Now, if Mazda does adopt rumored and patented exotic ignition technology, all bets are off. They patented plasma jet ignition and have experimented with prechamber systems. There have also been rumors of laser ignition.
There's all sorts of strange wankel rotary designs that have been used in experimental engines or in low production applications (single rotor air cooled single spark plug small engines).
12-03-12, 10:41 PM
#13
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Not to mention different bath tub designs were explored endlessly. Mazda has tried that one, albeit with a properly cast rotor, not a butchered nightmare, and did not find that it was more efficient. Mazda may not have tried everything on these engines, but they sure have tried a lot more than these commonsensical features...
12-03-12, 10:58 PM
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See this is what I'm talking about
Anyone can critique
But if you can't give an explanation or feedback why bother?
But this is some good info you guys are posting keep it up
Anyone can critique
But if you can't give an explanation or feedback why bother?
But this is some good info you guys are posting keep it up
12-04-12, 07:30 AM
#16
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By making the leading plug hole smaller, you affect the spark actually reaching the air/fuel mixture in the chamber. The trailing plug hole is small, so I'm sure Mazda has tried putting a small hole on the leading and it didn't work as well as a larger hole. If a smaller hole worked better, all of our housings would have 2 small holes instead of a large and a small.
As for the bathtub being moved, it seems like it would make sense in creating more low end torque. But same argument as above, if a shifted bathtub was a superior design, we would all have those kind of rotors instead of the kind we have now. One thing that wasn't mentioned was split spark, and I think that might have a little to do with bathtub design and placement.
Neither of these ideas are going to affect my drag racing (or lack there of).
12-04-12, 10:26 AM
#17
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At the end, everything that's been said in this thread are all theories. You guys are drawing stuff on paper to prove him wrong when this guy is claiming that the results of his testing decreased the egt's by 600 degrees. Now I'm not saying its true but I wouldn't go as far as saying he's lying because it does makes sense.
If you shape the spark plug hole so that its covered when the apex seal passes over it, wouldn't that stop compression from leaking into the exhaust chamber before its ignited? Why not? As far as the spark plug hole being too small, just because the shape of the hole is changed, it doesn't mean that it's smaller. If size is the problem, the slotted spark plug hole can always be made wider.
If you shape the spark plug hole so that its covered when the apex seal passes over it, wouldn't that stop compression from leaking into the exhaust chamber before its ignited? Why not? As far as the spark plug hole being too small, just because the shape of the hole is changed, it doesn't mean that it's smaller. If size is the problem, the slotted spark plug hole can always be made wider.
12-04-12, 10:42 AM
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Here is one of the documents I was referring to, from Kenichi Yamamoto's RE comparing a forward configured combustion chamber vs the standard symmetrical combustion chamber. I know I've seen another article comparing a bunch of different bathtub designs/locations, but can't seem to find it now, although the result was the same, hence the choice in today's Medium Deep Recessed rotor.
Note how the Leading Deep Recessed rotor configuration did result in lower EGT's, just like the guy in the video's ghetto rearward-configured CC did, but did not result in better emissions, so the guy was wrong to assume that EGT's are directly equal to NOx or other emissions. This is where the difference between backyard mechanics' assumptions and measuring devices are way behind Mazda and others' testing programs.
Point is, these things have been tried, and the resulting configuration today is due to it being the most optimal choice in regards to performance and emissions, though that's not to say that there aren't improvements to be found.
Note how the Leading Deep Recessed rotor configuration did result in lower EGT's, just like the guy in the video's ghetto rearward-configured CC did, but did not result in better emissions, so the guy was wrong to assume that EGT's are directly equal to NOx or other emissions. This is where the difference between backyard mechanics' assumptions and measuring devices are way behind Mazda and others' testing programs.
Point is, these things have been tried, and the resulting configuration today is due to it being the most optimal choice in regards to performance and emissions, though that's not to say that there aren't improvements to be found.
12-04-12, 10:52 AM
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At the end, everything that's been said in this thread are all theories. You guys are drawing stuff on paper to prove him wrong when this guy is claiming that the results of his testing decreased the egt's by 600 degrees. Now I'm not saying its true but I wouldn't go as far as saying he's lying because it does makes sense.
If you shape the spark plug hole so that its covered when the apex seal passes over it, wouldn't that stop compression from leaking into the exhaust chamber before its ignited? Why not? As far as the spark plug hole being too small, just because the shape of the hole is changed, it doesn't mean that it's smaller. If size is the problem, the slotted spark plug hole can always be made wider.
If you shape the spark plug hole so that its covered when the apex seal passes over it, wouldn't that stop compression from leaking into the exhaust chamber before its ignited? Why not? As far as the spark plug hole being too small, just because the shape of the hole is changed, it doesn't mean that it's smaller. If size is the problem, the slotted spark plug hole can always be made wider.
As for the spark plug hole, what makes you think that the intake charge really wants to leak from the intake chamber to the following combustion chamber? Things leak when there is a pressure differential, and in the case of those two chambers over the leading spark plug hole, there is relatively none at the time the apex seal passes over it. It is designed this way for a reason.
12-04-12, 01:46 PM
#23
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As for the spark plug hole, what makes you think that the intake charge really wants to leak from the intake chamber to the following combustion chamber? Things leak when there is a pressure differential, and in the case of those two chambers over the leading spark plug hole, there is relatively none at the time the apex seal passes over it. It is designed this way for a reason.
Ok I get this and I didn't think of it, but being that he trying to direct all of that air and fuel at the bottom of the rotor with the thought of it being offset, he actually moved the trailing spark plug hole to where the leading actually is and the leading is now pretty far down in comparison to the stock position. So there's a chance that the exhaust will probably be opening by the time the apex seal passes the leading spark plug and or could change the pressure between the two chambers at some giving point...I'm not sure But one thought of flaw that comes to my mind is that the rotor will lack it full combustion charge because the exhaust will open a lot sooner, but then again I'm not sure I'm just thinking. Now that I think about it, I'm sure how it will run with timing so retarted.
Ok I get this and I didn't think of it, but being that he trying to direct all of that air and fuel at the bottom of the rotor with the thought of it being offset, he actually moved the trailing spark plug hole to where the leading actually is and the leading is now pretty far down in comparison to the stock position. So there's a chance that the exhaust will probably be opening by the time the apex seal passes the leading spark plug and or could change the pressure between the two chambers at some giving point...I'm not sure But one thought of flaw that comes to my mind is that the rotor will lack it full combustion charge because the exhaust will open a lot sooner, but then again I'm not sure I'm just thinking. Now that I think about it, I'm sure how it will run with timing so retarted.
12-04-12, 01:50 PM
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bigdv, PM me your email address, I can send you the literature I have if you're interested. It's really handy if you're trying to become an honourary forum smart-***. 