Rotors Magazine Lots of people (myself included) want to buy a rotary car (RX8 are really cheap right now). Make a video about what new buyers need to watch out for!
steph sek i wouldnt buy a rx8 2 much problems and they are heavy if u want to get into rotary buy a fc cheaper on parts then a fb only thing good out of a rx8 are the rotors to be honest
Oliver Zbinden glad I don't live in europe then. None of my cars would be cheap to insure and probably wouldn't be legal anyways. My 91 bmw 318 has a 2002 camaro ls1 6speed combo, hell, all three of my cars have an ls1 in them. Best thing I ever did to the rx7, more useable power under the curve, better gas mileage, and cheaper to maintain. It's a first gen rx7 so i didn't "deface" an fd twin turbo...although I would if I had one...
My personal view on this topic: 0,654L is the air a rotor can displace in one turn me thinks (the 3 gaps the rotor constantly creates in the chamber). So, a 2-rotor engine has indeed 1.3L of air volume. And since a rotary engine cannot compare to any other engine, the true volume is 0,654L per rotor since it gets this volume per turn. The 2 and 4-stroke engines have their specified volume in its combustion chamber per cylinder when the piston is in its lowest point. Tha's how the engine dispacement is done. Rotors have a constant volume that intakes, sparks and exchausts its air-fuel mixture 3 times per turn and that's why it makes so much power and is able to reach so high rpms for such low volume. And that's why it consumes so much fuel also. But Honda S2000 reaching almost 10K rpms, consumes almost the same amount of fuel as the RX8, producing almost the same power and torque. So, the size and weight of the rotary engines are the main pros helping to create 50/50 weight distribution in sports cars. No need to put those engines in family cars or GTs. These engines are the recipe for handling machines. Let's wish Mazda manages to bring them back to production sometime soon-ish using new techs (hybrid tech maybe?) to reduce emissions and consumption.
giorx5 Can a rotor handle multiple displacement like many V8s (shutting down cylinders when all aren't needed)? That would be one way to reduce emissions and fuel consumption.
joerapo that could be possible on the 3 and 4 rotor designs, depending on the ecrank's positioning for each and also having a way to lubricate the apex seals without it not flooding the rotor and exhaust with unburnt oil
Sorry, but that is not how displacement in any engine is calculated. You must use the total volume of air displaced in the same number of shaft rotations need to complete the engines firing order sequence. 2-stroke Benz-Cycle 360° 4-stroke Otto-Cycle 720° 4-stroke Wankel-KKM 1080°
Im glad you explained this but its funny how this debate starts when a rotary this or that mops the floor with any piston engine after a race,im 2jz now but always been IN LOVE WITH THE BRAP!
.65 + .65 =1.30 which is 1.3l since one face fires and completes revolution with the second trailing. That one face .65 is half the complete cycle. The face of the second rotor literally trails it a.65 so with three rotations of the e shaft 2 rotors have fired one face at a time. And only one rotor is firing at a time. So that one face on each rotor is the only measurement you can take. Its a 1.3l no matter how many faces it has because only one face fires at a time.... again .65 +.65 gives you 1.3l period there is no argument
RR made it a diesel, but it had very low braking force, where as a diesel ic have good braking force. If the breakthrough works, it may be good for cars, but not for trucks. If they can get the fuel consumption right. In a boat-test, a 100 HP two-stroke, used 44 litres petrol, and a 4-stroke 100 hp used 28 litres, for the same work.
There's actual displacement and then there's "but to compare to a piston engine" displacement. a 13B engine is 1.3L period, some people bitched about it and thats where this 2.6L/3.9L non-sense comes from. Below is an explanation that I think explains both sides very well: Wankel engines can be classified by their geometric size in terms of radius (rotor center to tip distance, also the median stator radius) and depth (rotor thickness), and offset (crank throw, eccentricity, also 1/4 the difference between stator's major and minor axes). These metrics function similarly to the bore and stroke measurements of a piston engine. Displacement is 3√3radius·offset·depth, multiplied with the number of rotors (note that this only counts a single face of each rotor as the entire rotor's displacement, because with the eccentric shaft - crankshaft - spinning at three times the rate of the rotor, only one power stroke is created per output revolution, thus only one face of the rotor is actually working per "crankshaft" revolution, roughly equivalent to a 2-stroke engine of similar displacement to ONE rotor face). Nearly all Mazda production Wankel engines share a single rotor radius, 105 mm (4.1 in), with a 15 mm (0.59 in) crankshaft offset. The only engine to diverge from this formula was the rare 13A, which used a 120 mm (4.7 in) rotor radius and 17.5 mm (0.69 in) crankshaft offset.[citation needed] As Wankel engines became commonplace in motor sport events, the problem of correctly representing each engine's displacement for the purposes of competition arose. Rather than force the majority of participants (driving piston engine cars) to halve their quoted displacement (likely resulting in confusion), most racing organizations simply decided to double the quoted displacement of Wankel engines.[1] The key for comparing the displacement between the 4-cycle engine and the rotary engine is in studying the degrees of rotation for a thermodynamic cycle to occur. For a 4-cycle engine to complete every thermodynamic cycle, the engine must rotate 720° or two complete revolutions of the crankshaft. The rotary engine is different. The engine rotor rotates at 1/3 the speed of the crankshaft. On two rotor engines, front and rear rotors are 180° offset from each other. Each rotation of the engine (360°) will bring two faces through the combustion cycle (the torque input to the eccentric shaft). This said, it takes 1080° or three complete revolutions of the crankshaft to complete the entire thermodynamic cycle. Obviously, there is a disparity. How can we get a relatable number to compare to a 4-stroke engine? The best way is to study 720° of rotation of the two-rotor engine. Every 360° of rotation, two faces of the engine complete a combustion cycle. 720° will have a total of four faces completing their cycle. 40ci(654cc) per face times four faces equals 160ci or 2.6L. That's a well-reasoned number and now gives something that can be compared to other engines. In addition, since four faces passed by in the comparison, it’s like a four-cylinder engine. The 13B therefore compares well to a 2.6L 4-cylinder 4-cycle engine.[1] By using the same formula, calculating actual displacement in which 1080° is the complete thermodynamic cycle of a rotary engine and a total of six faces completing their cycle, 40ci(654cc) per face times six faces equals 3924cc, 3.9L, or 240ci, in reference to a Mazda 13B rotary engine. "Each face has a swept volume of 40ci(654cc) and there are a total of six faces. With this known, the engine displacement should be 40ci(654cc) times six to equal 240ci(3.9L)."[1]
*Unless your engine does not intake, fire or exhaust an air charge every third crank rotation then you sir just proved its a 3.9 liter in total displacement... you can't have it both ways.*
Looking at that diagram you provided (good job btw lol 👌🏼) I would say the rotary is more of a hybrid between 4 stroke and 2 stroke.. looks like it's a 3 stroke as the intake stroke is separate from the compression stroke, but then the ignition and exhaust are basically the same stroke.. pretty cool if you ask me! Can't wait to rebuild my rx8 this summer.. still runs decent with 210xxx km on it! 😝
Bradley Smith my 12a not stock at all full bridge 12a monster street port running a 48 webber down draft it all depends how u drive but im always on mine 100% throttle
Have had 4 rotary powerd cars in my life, love them, now I own a Honda but I'm going to start looking for another rotary powerd car, as soon as I can, love the content 👍
Displacement of engine is volume of displaced air, sucked into engine, after all pistons/faces have fired, under condition of 100% volumetric efficiency. If every face of rotaty engine can displace 0.65L of air, total displacement after all 6 faces have fired is 3.9L. Engine is called 1.3 because of tax reasons. In Europe some countries have luxury cap on 2L and above. In Japan I think it is about 2.5 or 3L. For Kei cars, it is 0.66L, so they might use single rotor for Kei car. And as rotary is very rare and not very much people understand it, Mazda could say whatever they want.
Exactly. The practice of only counting 1 chamber per rotor started at NSU (first builders of the Wankel) at the suggestion of Max Bentele (visiting engineer) to avoid EU displacement taxes.
Thanks for posting your videos Kenny. You are in the camp of not caring but how many liters do you think the 13B engine is? I just found your channel. Why does Mazda recommend not using synthetic oil for their rotary engines? I used to use synthetic in my 91 13b but a very experienced rotary engine mechanic at Mazda convinced me to reluctantly change to mineral oil. He kind of said I would not understand why. What do you use?
Edward Dergosits In a nut shell, they recommend not to use synthetic oil if you are still running the stock oil metering pump. The reason for this is conventional oil burns easier. The Oil Metering pump (OMP) injects oil into the rotor housing much like a fuel injector to help keep the apex seals lubricated. The OMP tends to quit working, so the most common fix is the remove the OMP all together and premix the gas using two stroke oil. Once you’ve done that you are safe for synthetic. Just our $.02!
That is the best explanation I have heard Kenny. I assume that using synthetic would cause the catalytic converter to be overloaded. I replaced the OMP two months ago. Pricey fix it was.
Very very interesting! Very good work. Something I have never really thought about. I am also in the camp of don't really care. The only replacement for displacement is Rotary. Rotary life
1.3l is correct if you look at it the way the manufacturer looks at it. Only two faces fire 🔥 per power stroke/ i.e. Turning thermal energy into kinetic energy 13b= bang bang/applied motion. 2.0l piston engine= bang bang bang bang/ applied froward motion I feel 1.3l is the the most accurate displacement description
When mazda came out with the rotary they said it's a 1.3l, now every dum ass comes up with their own theory just because a 1.3litre rotary makes too much power
+MrChayl3 *Mazda didn't come out with the Wankel engine... they bought it from the company that invented it...NSU. NSU concocted the bullshit method that was used to cheat the tax collectors in countries where registration is based on engine size... today you pay the much higher amount based on the larger true displacement.*
NUCLEAR WANKEL ENGINE But there is a way, says Mark Adams, an MIT-educated physicist and former staff member at the Lawrence Livermore National Laboratory in California. He has designed an engine that he calls an “internal” rotary engine, rather like the kind of Wankel engine that has been around since the 1950s. Instead of pistons going up and down, the engine has a rotor that rotates around a crank shaft. The rotary engine that Adams envisions looks diagrammatically very like a schematic of the rotatory engine that Mazda introduced to varying degrees of success in its cars in the 1970s. It works like this: A small amount of gasified “nanofuel,” which contains nuclear material mixed with hydrogen, is ignited by a neutron source to set up a controlled fission reaction, creating heat and propelling the rotor forward and driving the crank shaft. The fuel can be derived from the transuranic parts of spent conventional nuclear fuel or can be created separately.
It's nice that Mazda placed this engine in low insurrance rate... ;-) Thanx SO much, loving fan of your worki, with crash on RX8 revolution and beloved by all family 323F from 1998 :-)
@@doktorbimmer +SuperRage Oholic if you keep telling doktorbimmer that he will start crying. Wankel engines are intimately related to his type of schizophrenia. WANKEL ROTARY ALL THE COMPANYS WILL BE MAKING WANKEL ENGINES ONCE AGAIN
If we compare two crank revolutions of the piston motor to two eccentric shaft revolutions on a rotary is that not equivalent to 2.6L? Hence, why racing series and insurance companies often view the rotary as a 2.6L.
Only problem with this video is you keep stating displacements as a fixed value. A rotary engine does not only displace 1300cc's. A Mazda 13b(A) engine displaces 1300cc's per combustion. You kept stating several times that "rotaries" have a value of 1.3 liters. This is wrong terminology, a rotary engine can come in several different sizes, just as normal piston engines come in different sizes. Yes, the mazda 13b is the most common.
Having owned six first-gen RX7s (and rebuilt a few rotaries) I'm in the 2.6L camp. The crank completes three rotations for every single rotation of both rotors. Therefore, each rotor fires on two of their three faces for every two rotations of the crank (eccentric) shaft - which is the same number of rotations required to complete the full cycle of a four-stroke engine, which the rotary definitely is. Since a total of four rotor faces produce a power "stroke" during these two eccentric shaft rotations we get 4 x 0.65L = 2.6L displacement. Incidentally, that works out to two power strokes per revolution for a two-rotor engine, the same as that of a 4-cylinder piston engine. But here's where things get interesting: The duration of the power stroke in a piston engine (as the piston is forced downward from TDC to BDC) is 180 degrees of crankshaft rotation. In a rotary, the duration of the power "stroke" is 240 degrees of eccentric shaft rotation - 50% longer than that of the piston engine. This provides a longer and smoother power delivery per power cycle, and the extra 50% in degrees of power stroke length is the equivalent of having an extra two cylinders (50% of four cylinders = 2 cylinders, 4 cylinders + 2 cylinders = 6 cylinders). That fact, combined with the absence of reciprocating components, is why the rotary runs as smoothly as it does.
Many thanks for this video. I have been pondering myself how to measure the true volume of a rotary engine. As you say in a 4 stroke cycle engine there are 4 components to that cycle. Now as the 4 stroke cycle in a rotary takes place in 360 degrees as opposed to a piston engine this takes place in 720 degrees. So we also have 3 chambers per rotor so i say that a rotary is similar to a 3 piston engine per rotor. So a twin rotor is actually similar to a 6 cylinder piston engine. So in a 2 rotor engine with 6 chambers of 650cc that makes it 3900 cc . If you then add that there are 2 firings in 720 cc compared to a piston you could consider the 2 rotor to actually be 7800cc for 720 degree cycle. The other problem of a rotary compared to a piston is that in a piston the power stroke lasts 180 degrees but but in a rotary that is 90 degrees. So the work available is for a much shorter duration. The other problem is that a piston engine has a much larger Crank or lever moment so produces much more torque compared to a rotary. But will not rev a fast as a rotary. I will admit to loving rotaries but never had the balls to actually buy one. I loved the RX8 R3 that i nearly bought a few years ago.
Citroen and Van Veen also experimented with Wankel, but only NSU and Mazda had Wankel commercialized. A nice thought to rotate instead of the existing up/down engines, but some bad hooks: bad compression control, bad fuel consumption and bad CO2 creation.
All 3 faces should count towards total displacement. That being said its a 3.9L engine that you can pick up by yourself, so still a great innovation. Also makes up for the terrible MPG.
Why not compare BSFC between the rotary and some typical 1.3, 2.6 and 3.9L 4 stroke cycle engines? Obviously that doesn’t measure displacement and is meant as a measure of efficiency, but it might show where the rotary most closely resembles a 4 stroke reciprocating engine.
Here in California, the very first government agency was formed to introduce motor vehicle emissions standards in 1967, still the strictest air pollution standards in the world, Diesel fueled vehicles have always been classified as clean, low emissions vehicles and were even EXEMPT emissions regulations and the bi-annual testing program for 30 years. Yes, it is possible to observe something and still not understand what you are seeing.. especially if you are not knowledgeable on the issues.
I'm reluctant to say that this notion really makes sense, even if that's how it's officially measured. I'd say that an engine's displacement is best described as the volume available for one power stroke's fuel mixture, before compression, all "cyclinders" combined. (i.e. how much mixture could ideally be burnt per power stroke, if the engine was naturally aspirated). No crankshaft revolutions in this definition.
I believe the reason that it's 1.3L from factory as you stated is that 4 cycles happen on 1 E shaft rotation an as stated thats the amount of air expelled from 1 rotation. Equally understand that for comparison. The 2.6 makes more sense as piston takes the 2 rotations to complete the 4 cycles. But yeah people gonna hate if it's a 1.3, 2.6 or a 3.9. People always hate what they don't understand.... Loving the Cosmo BTW.
This makes sense ... 2 rotations = 2.6L and 1 rotation = 1.3L ..... So I would be correct when saying that a 1.3L Rotory is equal to a 2.6L engine. .... air volume speaking.... yep it does make sense.... thanks for that good info ...
Exactly! It's equivalent to a 2.6L 4-cycle piston engine in terms of air volume. Notice the exact wording of this; I'm not saying that's it a 2.6L engine, merely that it's equivalent!
This makes so much more sense now. 24mpg from a 1.3L didn't make sense to me, but 2.6L is more understandable for the 24mpg figure. I think your right that the engine isn't a two cycle, but it still lubricates like one. It isn't really a true four cycle either. I'd just call it a Wankel cycle. Because Wankel stroke would be the butt of too many jokes.
Each face would need to be counted as an individual cylinder. A traditional piston can only have one cycle happening at once. In a rotary, when one face is in the Ignition cycle, one face is on intake and the other is exhaust, so it can have three happening at once. Also, from ignition to complete exhaust is a half turn of the crankshaft. It is literally just a 3 cylinder engine in one object, therefore, if each face can house .65L of air, then each rotor would be equal to 1.95L, so a two rotor would be 3.9L (or a 3.9L 6 Cyl), a 3 rotor would be 5.85L (or a 5.85L 9Cyl), and a 4 rotor would be 7.8L (or a 7.8L 12 Cyl). The traditional Engine Displacement definition can literally not be applied to a rotary, even if you replace "piston" with "rotor", because you would have to basically pretend the other two faces of the rotor aren't doing anything. I propose a new definition: "Rotary engine displacement is the swept volume of all the rotors inside the rotor housings of a reciprocating engine in a single movement from Top Dead Centre (of the ignition stroke) to Bottom Dead Centre of the crankshaft times 3 (to account for the 3 faces of one rotor)."
Yes, basically, it's because the Wankel rotary engine's displacement isn't measured in the same way as a piston engine. If you measure a 6.2L LS3 the same way Mazda measured the 13b to end up with 1.3L an LS3 would be a 3.1L engine. What many people have a hard time with is keeping the ENTIRE engine, all 6 faces of the rotors on a 13b, in mind at once along with the Wankel's 3:1 ratio. During operation, because there is a 3 to 1 ratio between the rotors and the eccentric shaft or e-shaft (equivalent to the crankshaft) that means for every 1 revolution of the e-shaft the rotors turn 120 degrees (1/3 of a revolution) which is the number of rotor degrees necessary to complete one phase on each rotor face. This results in 1 intake, one compression/power, and one exhaust PER rotor (although there is overlap because the second rotor is phased or "follows" the first for balancing reasons). This means in 1 revolution of the e-shaft the entire engine's swept volume displacement is .65 * 3 faces * 2 rotors= 3.9L. The main reason, I think, for this odd way of mesuringdisplacement that Mazda used that resulted in the 1.3L rating, only counting one rotor face per rotor, is because, esp. in Japan, insuring a 1.3L sports car is much cheaper than a 3.9L sports car as well as the fact that Japan has an absurd "displacement tax" so the smaller the rated displacement of the engine the better.
Internal Combustion Engines are known being linked to low Effective Compression Ratio, these first times because of poor quality of available gasoline. If changing the plug hole to an slot as Ernie Brink proposes, reduces greatly the Exhaust Gas Temperatures, this would mean a much higher Effective Compression
Put a 13B on a dynamometer with an airflow meter. Run the engine at a known speed and measure the airflow. Calculate the volumetric efficiency. You can't get the same numbers saying that the engine displaces 1.3, 2.6, and 3.9 liters. Only one displacement will yield a vol eff number in the range of 100%. That would be 1.3 L. The other "displacements" would yield numbers of 50% and 33%. The key detail is that the volumetric efficiency of an internal combustion engine is defined on the basis of mass air flow through one thermodynamic cycle. This is not only a function of piston displacement, but also of valves controlling the airflow. It takes two revolutions of the the crank in a 4-stroke engine to complete one thermodynamic cycle, but only one revolution of the camshaft. That's because it's the camshaft that controls the airflow.
All things considered I would say you should not compare it to 4 or 2 stroke. It's a rotary! For me a 4 stroke has to have valves. Thats why i also understand why people comepare it to 2 stroke specially when it comes to sound.
Ye I had an rx 8 for 10 lovely months b 4 it blew a seal due too cat failure, am also an engineer an I agree with the 2.6 litres as if you compare too a normal in-line 4 engine 2 crank revelations is what we would measure too then using the same amount makes for a more equal comparison 👍🏼
APEX SEAL LEAKS INSIDE THE ENGINE ON COMPRESSION STROKE THIS WHY YOU GET 80LBS ON A COMPRESSION CHECK THIS ENGINE IS 5 TO 1 RATIO WHEN IT LEAKS INSIDE THE ENGINE LOOKING FOR A 10 TO 1 ROTARY
Not just RX7 and RX8. The old Mazda cars are the best. Very big in drag racing and on the street. R100, RX2, RX3, RX4. You should change the title of this video.
ive been a rotary freak but i dont have the technical knowledge that you guys have.I had a nice swap with 12a on a 82Celica body and it moved. miss the torque and the beatiful music coming out of the exhaust.I wnna do another swap witha 20b when im finacialy stable.Great coments with the wankel engine and keep more videos coming. by the way I cant wait to see the RX9 in the Chicago Auto Show . Happy Holidays
When asking why a small displacement engine can make big power, it's because displacement is irrelevant. What is relevant is airflow, because an engine is an airpump. That's why the same engine with different heads, cams, etc makes different amounts of power.
Yes you are correct but NOT different amount of torque ....an NA 13B is nowhere close a 2.6L in torque let alone a 3.9 Lit. So rotary (in real life not calculations) is equivalent to 2-2.2 piston in power and torque ....... and nobody actually bothered to answer HOW is the capasity of the 0.65 lit measured..... is all the "air"/"water" one housing can include or one rotor face..... from WHAT degrees up to what degrees? .....
I have compaired the 2 roter to a v6. Same number of "cylinder's" so yeah 3.9L. Except for the number of power strokes which is the same as a v8, two per one revolution. No wonder people get confused about the rotary.
Your explanation is wrong though. "Engine displacement is the swept volume of all the pistons inside the cylinders of a reciprocating engine". Problem is, the rotary doesnt have pistons and it is not a combustion engine with reciprocating motion. The rotors are basically the "pistons" on the Wankel engine. In a four stroke, two full revolutions of the crankshaft are required for all the pistons to have fired at least once. In the Wankel engine, for each revolution of the e-shaft, two faces fire at the same time. If I go by your logic, that would mean the rotary needs 3 revolutions of the e-shaft for all the faces to fire and not one, so the bond with the 2 stroke engine kinda goes away. It is hard to really understand the displacement of a rotary, but you got it wrong. The difference lies in your example. A 4 cyl four stroke has four combustion chambers, so you need all the four pistons to fire at least once for you to know how much air got into each combustion chamber. So if two pistons fired once, the other still have to, so you can't tell the displacement until then. On a rotary, there are two combustion chambers. All six faces have 654cc. But only two of them, one per rotor, for each revolution, has a power stroke. In one of the rotors, if face number 2 let's call it, has a power stroke, face number one is the intake stroke and face number two is in the exhaust stroke. But don't misunderstand this. Even if I said the faces were on some "strokes", you shouldn't treat them as pistons. That is the tricky part. But you don't consider exactly how MUCH air the engine is taking. If by one single revolution, in the 4 cyl, only half of the maximum intake of air has gone into the engine, in the rotary, in one single revolution, the maximum air intake has already been reached, which, in the case of the 13B, is 1.3L. You just keep adding air for all the six faces as if the engine could take more than 1.3L, you're just repeating the cycle. The reason for all the power of a rotary is indeed because of how fast each power stroke succeeds one another.
*Sorry, but the Wankel KKM IS A 4-STROKE so we calculate displacement at 1080° NOT 360°* *Its not that difficult to understand... each orbiting piston(rotor) has 3 sides forming 3 combustion chamber volumes, each with a swept volume of 654cc. times the 2 housings is 6 and equaling 3,924cc.* *The other important thing that people without formal engineering experience fail to understand is that a 4 cycle Otto or Diesel engine completes its firing sequence in 720° of crankshaft rotation while the 4-cycle Wankel KKM designs required 1080° of rotation to complete its firing sequence...* *These two important and often misunderstood details are the basis of the commonly used "2X" conversion formula for accurately "comparing" the displacement of the Wankel with other designs..* *_Any questions? I would be happy to explain in more detail..._*
Wouldn't it be more of a 1 stroke and nothing even similar to a2 or 4 stroke just because all events are separate how does that make it 4 Stroke. When it does all 4 events in 1 cycle?please explain
*All Wankel engines use the same 4-stroke operating principle as the Otto engine, each of the 3 combustion faces goes through the 4 cycles separately just like a reciprocating engine does.*
I think it goes back to the fact that mazda wanted it to be under 1.5L so that japenese consumers would be taxed less. Since their was an additional tax for owning a car that displaced greater than 1.5L back in the day for Japan
Someone shoulda further developed the rotary. Think about it, a 2 rotor engine has 3 moving parts, not much friction really and you could make higher compression rotors. Oil injection with the fuel would also help a lot with wear cos the fuel goes everywhere in the intake stroke and gets spread in the housings and irons. Youre gonna say something about pollution but put a DPF on it or rather an RPF(rotary particulate filter) and youd have clean emissions. Just a thought
Good educational vid, bt I count it that there is an ignition event every 120 of 360 degrees of the eccentric shaft, mayb it'd be easier to explain with a single rotor engine
Actually, there’s a combustion event every *180* degrees of e-shaft rotation. Very much like a 4 cyl. On older Rotaries that had a single dual-post (wasted spark) coil for leading ignition, you could run the engine leading only on most standalone EMSs by setting it up as a 4 cylinder 4 stroke with a single ignition output (like a distributor) and then just hook the single output to the leading coil. 4-cylinder engines have a combustion event every 180 degrees. IF you look at an actual e-shaft, the lobes are offset by 180 degrees as well.
I clicked on this video because the heading said "The SECRET Behind Why RX7 and RX8 Rotary Engines Make SO Much Power". Not how a rotory works in difference to a piston engine, I am still none the wiser. I wish people would reference their videos appropriately!
*No, it is not coming back. Despite all the fake clickbait rumors on the automotive blogsites, Mazda discontinued development of Wankel engines in May 2009 and has permanently ceased all production.* *Mazda's CEO has stated officially that the company has no plans to resume any production and there is absolute zero evidence to prove otherwise.*
*Mazda and Toyota have only confirmed a joint project with Denso to built zero-emission battery electric vehicles to comply with new laws in California and 11 other states.* *Both companies recently lost a bid to allow range extenders and hybrids under the new law that went into effect this year.. If Mazda does not offer a zero emissions car by 2023 it will be banned from selling any cars in California (Mazda's largest and most profitable market).*
great info when you line up a apex in the leading plug hole you see two chambers at the same time HEAT IS NO GOOD so two keep your turbo and engine in great shape you must stop the flames that are inside the engine before it ever comes out of the housings
Every car guy should have a rotary in their car collection!... Car guys have at least 3 cars! ...Wife car count!... IF you're doing the mechanical work in it!... 😎👍
1.3L makes perfect sense if you will stop bashing those of us that maintain that the rotary engine is really a two stroke. A 4 stroke engine uses a full stroke (piston at TDC to BDC) for each phase, intake, compression, power, exhaust. While a two stroke technically has all 4 phases, but each phase only takes 1/2 of a stroke. A single piston 4 stroke engine fires once every 2 revolutions, while a 2 stroke fires every revolution. A rotary engine fires every revolution making it a 2 stroke engine. Remember, a stroke is 1/2 rotation of the crankshaft, not a phase described as intake, comp, power, exhaust. In a 4 stroke engine the strokes are thus named because each phase uses a single stroke, but don't project that naming convention to the stroke. The definition of the word stroke = "noun 1. an act of hitting or striking someone or something; a blow." You description gets confusing because of your initial assumption that the rotary is a 4 stroke. If you assume that the rotary is a 2 stroke, it all works out nicely. Nothing confusing about it. And as we all know, 2 strokes make more power / displacement than a 4 stroke, simply because it fires twice as often!
What should we talk about next on Rotary Theory?
Please talk about the differences between 4-port, older style 6-port , and the Renesis.
Rotors Magazine Lots of people (myself included) want to buy a rotary car (RX8 are really cheap right now). Make a video about what new buyers need to watch out for!
steph sek he did look back at the older video on RX8
steph sek i wouldnt buy a rx8 2 much problems and they are heavy if u want to get into rotary buy a fc cheaper on parts then a fb only thing good out of a rx8 are the rotors to be honest
Rx8’s are not heavy lol
Torque of a 1.3L, power of a 2.6L, fuel economy of a 3.9L. Simple.
evidence.
hey bro need more help FAKE TROLL az616578.vo.msecnd.net/files/2016/08/27/6360787077700554381193066848_Internet-Troll.jpg ON ALL ROTARY SIGHTS
Torque performs like a V8 what are you tryna to say?
@@thatcornfedrx8guy372 BAHAHAHAHAHAHAHAHA....... Like a V8 he says
@@stlchucko so then tell my why modified rotarys use differentials out of torquey Pickups.
It helps to have 1.3 rather then 3.9 car when insuring your car :P
Pecetos in europe (at least where i live) you pay insurance for 2.6l 😉
negative in here it's state as 1.3l ;)
Pecetos not when it’s a twin turbo 1.3l with two seats
actually they have a bench in back with bucket seats so its a 4 seater (even tho nobody can fit in the back except maybe your dog)
Oliver Zbinden glad I don't live in europe then. None of my cars would be cheap to insure and probably wouldn't be legal anyways. My 91 bmw 318 has a 2002 camaro ls1 6speed combo, hell, all three of my cars have an ls1 in them. Best thing I ever did to the rx7, more useable power under the curve, better gas mileage, and cheaper to maintain. It's a first gen rx7 so i didn't "deface" an fd twin turbo...although I would if I had one...
My personal view on this topic: 0,654L is the air a rotor can displace in one turn me thinks (the 3 gaps the rotor constantly creates in the chamber). So, a 2-rotor engine has indeed 1.3L of air volume. And since a rotary engine cannot compare to any other engine, the true volume is 0,654L per rotor since it gets this volume per turn. The 2 and 4-stroke engines have their specified volume in its combustion chamber per cylinder when the piston is in its lowest point. Tha's how the engine dispacement is done. Rotors have a constant volume that intakes, sparks and exchausts its air-fuel mixture 3 times per turn and that's why it makes so much power and is able to reach so high rpms for such low volume. And that's why it consumes so much fuel also. But Honda S2000 reaching almost 10K rpms, consumes almost the same amount of fuel as the RX8, producing almost the same power and torque. So, the size and weight of the rotary engines are the main pros helping to create 50/50 weight distribution in sports cars. No need to put those engines in family cars or GTs. These engines are the recipe for handling machines. Let's wish Mazda manages to bring them back to production sometime soon-ish using new techs (hybrid tech maybe?) to reduce emissions and consumption.
giorx5 Can a rotor handle multiple displacement like many V8s (shutting down cylinders when all aren't needed)? That would be one way to reduce emissions and fuel consumption.
Let's see what Mazda engineers find out in the near future to make it happen.
joerapo that could be possible on the 3 and 4 rotor designs, depending on the ecrank's positioning for each and also having a way to lubricate the apex seals without it not flooding the rotor and exhaust with unburnt oil
Sorry, but that is not how displacement in any engine is calculated. You must use the total volume of air displaced in the same number of shaft rotations need to complete the engines firing order sequence.
2-stroke Benz-Cycle 360°
4-stroke Otto-Cycle 720°
4-stroke Wankel-KKM 1080°
Derpin Bird: LOL, is there anyone on the internet you haven't started a fight with? Pathetic loser.
well my insurance costs are pretty happy with a 1.3 L 4 door car ;P
2.6 liter
3.9L
There's a video that explains with math and physics why the 13b is 1.3 liters.
Im glad you explained this but its funny how this debate starts when a rotary this or that mops the floor with any piston engine after a race,im 2jz now but always been IN LOVE WITH THE BRAP!
.65 + .65 =1.30 which is 1.3l since one face fires and completes revolution with the second trailing. That one face .65 is half the complete cycle. The face of the second rotor literally trails it a.65 so with three rotations of the e shaft 2 rotors have fired one face at a time. And only one rotor is firing at a time. So that one face on each rotor is the only measurement you can take. Its a 1.3l no matter how many faces it has because only one face fires at a time.... again .65 +.65 gives you 1.3l period there is no argument
RR made it a diesel, but it had very low braking force, where as a diesel ic have good braking force. If the breakthrough works, it may be good for cars, but not for trucks. If they can get the fuel consumption right. In a boat-test, a 100 HP two-stroke, used 44 litres petrol, and a 4-stroke 100 hp used 28 litres, for the same work.
Agreed!
There's actual displacement and then there's "but to compare to a piston engine" displacement. a 13B engine is 1.3L period, some people bitched about it and thats where this 2.6L/3.9L non-sense comes from. Below is an explanation that I think explains both sides very well:
Wankel engines can be classified by their geometric size in terms of radius (rotor center to tip distance, also the median stator radius) and depth (rotor thickness), and offset (crank throw, eccentricity, also 1/4 the difference between stator's major and minor axes). These metrics function similarly to the bore and stroke measurements of a piston engine. Displacement is 3√3radius·offset·depth, multiplied with the number of rotors (note that this only counts a single face of each rotor as the entire rotor's displacement, because with the eccentric shaft - crankshaft - spinning at three times the rate of the rotor, only one power stroke is created per output revolution, thus only one face of the rotor is actually working per "crankshaft" revolution, roughly equivalent to a 2-stroke engine of similar displacement to ONE rotor face). Nearly all Mazda production Wankel engines share a single rotor radius, 105 mm (4.1 in), with a 15 mm (0.59 in) crankshaft offset. The only engine to diverge from this formula was the rare 13A, which used a 120 mm (4.7 in) rotor radius and 17.5 mm (0.69 in) crankshaft offset.[citation needed]
As Wankel engines became commonplace in motor sport events, the problem of correctly representing each engine's displacement for the purposes of competition arose. Rather than force the majority of participants (driving piston engine cars) to halve their quoted displacement (likely resulting in confusion), most racing organizations simply decided to double the quoted displacement of Wankel engines.[1]
The key for comparing the displacement between the 4-cycle engine and the rotary engine is in studying the degrees of rotation for a thermodynamic cycle to occur. For a 4-cycle engine to complete every thermodynamic cycle, the engine must rotate 720° or two complete revolutions of the crankshaft. The rotary engine is different. The engine rotor rotates at 1/3 the speed of the crankshaft. On two rotor engines, front and rear rotors are 180° offset from each other. Each rotation of the engine (360°) will bring two faces through the combustion cycle (the torque input to the eccentric shaft). This said, it takes 1080° or three complete revolutions of the crankshaft to complete the entire thermodynamic cycle. Obviously, there is a disparity. How can we get a relatable number to compare to a 4-stroke engine? The best way is to study 720° of rotation of the two-rotor engine. Every 360° of rotation, two faces of the engine complete a combustion cycle. 720° will have a total of four faces completing their cycle. 40ci(654cc) per face times four faces equals 160ci or 2.6L. That's a well-reasoned number and now gives something that can be compared to other engines. In addition, since four faces passed by in the comparison, it’s like a four-cylinder engine. The 13B therefore compares well to a 2.6L 4-cylinder 4-cycle engine.[1]
By using the same formula, calculating actual displacement in which 1080° is the complete thermodynamic cycle of a rotary engine and a total of six faces completing their cycle, 40ci(654cc) per face times six faces equals 3924cc, 3.9L, or 240ci, in reference to a Mazda 13B rotary engine. "Each face has a swept volume of 40ci(654cc) and there are a total of six faces. With this known, the engine displacement should be 40ci(654cc) times six to equal 240ci(3.9L)."[1]
Nate Rist you have way too much time on your hands 😂
TJ25 not an argument.
Nate Rist props bro you know your shit!
Yeah i dont know where he pulled the multiple displacement shit out of his ass
*Unless your engine does not intake, fire or exhaust an air charge every third crank rotation then you sir just proved its a 3.9 liter in total displacement... you can't have it both ways.*
Looking at that diagram you provided (good job btw lol 👌🏼) I would say the rotary is more of a hybrid between 4 stroke and 2 stroke.. looks like it's a 3 stroke as the intake stroke is separate from the compression stroke, but then the ignition and exhaust are basically the same stroke.. pretty cool if you ask me!
Can't wait to rebuild my rx8 this summer.. still runs decent with 210xxx km on it! 😝
all i see is mpg comments lmao if u own a rotary the best part is filling up and adding pre mix ;) 12Agang
Jay Marley 12A mpg is not to terriable with 600km per tank running non premix regular gas
Bradley Smith my 12a not stock at all full bridge 12a monster street port running a 48 webber down draft it all depends how u drive but im always on mine 100% throttle
+Bradley Smith Well, its not too terrible until you consider the 12A makes little power and no torque.
Yeah, but you can't pre-mix an RX-8
600Km per tank??? Lies. That sounds like something that came out of a brochure for a Toyota Prius or Honda Insight.
Have had 4 rotary powerd cars in my life, love them, now I own a Honda but I'm going to start looking for another rotary powerd car, as soon as I can, love the content 👍
An ancient discussion that's just as interesting now as it was way back when. Great video.
Displacement of engine is volume of displaced air, sucked into engine, after all pistons/faces have fired, under condition of 100% volumetric efficiency.
If every face of rotaty engine can displace 0.65L of air, total displacement after all 6 faces have fired is 3.9L.
Engine is called 1.3 because of tax reasons. In Europe some countries have luxury cap on 2L and above. In Japan I think it is about 2.5 or 3L. For Kei cars, it is 0.66L, so they might use single rotor for Kei car.
And as rotary is very rare and not very much people understand it, Mazda could say whatever they want.
Exactly. The practice of only counting 1 chamber per rotor started at NSU (first builders of the Wankel) at the suggestion of Max Bentele (visiting engineer) to avoid EU displacement taxes.
*Great comments... nice to see some educated people in the comment section...*
Thanks for the vid Kenny. I am in the same boat as not caring but this is great to show people that swear it's a 2 stroke engine.
By the 3 crank rotation, the 787b had a 7.8L engine (when they said there's no replacement for displacement, they really weren't joking)
the text in the video had me dying lol. great video as usual
That's exactly what I always thought ! Have my 13B sitting in my garage looking for a car to install it into some day, thanks bro"
Ty for that answer its always a big debate over my engine. Since i am the only rotary guy in my car club.
Thanks for posting your videos Kenny. You are in the camp of not caring but how many liters do you think the 13B engine is? I just found your channel. Why does Mazda recommend not using synthetic oil for their rotary engines? I used to use synthetic in my 91 13b but a very experienced rotary engine mechanic at Mazda convinced me to reluctantly change to mineral oil. He kind of said I would not understand why. What do you use?
Edward Dergosits In a nut shell, they recommend not to use synthetic oil if you are still running the stock oil metering pump. The reason for this is conventional oil burns easier. The Oil Metering pump (OMP) injects oil into the rotor housing much like a fuel injector to help keep the apex seals lubricated. The OMP tends to quit working, so the most common fix is the remove the OMP all together and premix the gas using two stroke oil. Once you’ve done that you are safe for synthetic.
Just our $.02!
That is the best explanation I have heard Kenny. I assume that using synthetic would cause the catalytic converter to be overloaded. I replaced the OMP two months ago. Pricey fix it was.
Dude niice video, layed out perfect. I got no words for it. Thumbs up.
Great video, super educational. Explained it better than I have.
Hi Kenny, Thanks mate finally some one has made a simple video on this topic. We'll put . Cheers.
Brap stututu
iTZz Kittens compressor surge is bad for your turbo, get a bov
Brap stututu to you too!
Very very interesting! Very good work. Something I have never really thought about. I am also in the camp of don't really care. The only replacement for displacement is Rotary. Rotary life
1.3l is correct if you look at it the way the manufacturer looks at it. Only two faces fire 🔥 per power stroke/ i.e. Turning thermal energy into kinetic energy 13b= bang bang/applied motion. 2.0l piston engine= bang bang bang bang/ applied froward motion
I feel 1.3l is the the most accurate displacement description
When mazda came out with the rotary they said it's a 1.3l, now every dum ass comes up with their own theory just because a 1.3litre rotary makes too much power
+MrChayl3 *Mazda didn't come out with the Wankel engine... they bought it from the company that invented it...NSU. NSU concocted the bullshit method that was used to cheat the tax collectors in countries where registration is based on engine size... today you pay the much higher amount based on the larger true displacement.*
NUCLEAR WANKEL ENGINE But there is a way, says Mark Adams, an MIT-educated physicist and former staff member at the Lawrence Livermore National Laboratory in California. He has designed an engine that he calls an “internal” rotary engine, rather like the kind of Wankel engine that has been around since the 1950s. Instead of pistons going up and down, the engine has a rotor that rotates around a crank shaft. The rotary engine that Adams envisions looks diagrammatically very like a schematic of the rotatory engine that Mazda introduced to varying degrees of success in its cars in the 1970s. It works like this: A small amount of gasified “nanofuel,” which contains nuclear material mixed with hydrogen, is ignited by a neutron source to set up a controlled fission reaction, creating heat and propelling the rotor forward and driving the crank shaft. The fuel can be derived from the transuranic parts of spent conventional nuclear fuel or can be created separately.
It's nice that Mazda placed this engine in low insurrance rate... ;-) Thanx SO much, loving fan of your worki, with crash on RX8 revolution and beloved by all family 323F from 1998 :-)
doktorbimmer could you walk us through the moments you experienced when
you blew up your rotary?
His mind blew A few fuses that day and he hasn't been the same since!
He is A rotary 🌰 through and through but his 🌰 cracked!
Finally, someone understands that a 13b is 2.6 liters! Thank you! Kinda like a 2.6 liter 4 cylinder, except the 13b can rev much higher
Ive had 5 rx7s in my younger days... good times
15 bitch.
+Adam Smith 15 year old little bitch maybe? Your'e not even old enough to drive yet.
I had 4 days those were the dayz
@@doktorbimmer +SuperRage Oholic if you keep telling doktorbimmer that he will start crying. Wankel engines are intimately related to his type of schizophrenia. WANKEL ROTARY ALL THE COMPANYS WILL BE MAKING WANKEL ENGINES ONCE AGAIN
If we compare two crank revolutions of the piston motor to two eccentric shaft revolutions on a rotary is that not equivalent to 2.6L? Hence, why racing series and insurance companies often view the rotary as a 2.6L.
This is awesome, I have a 13B and this was eye opening. Thanks
definitely would be at the top of its class in displacement to power output which would be a plus in a commercial
Only problem with this video is you keep stating displacements as a fixed value. A rotary engine does not only displace 1300cc's. A Mazda 13b(A) engine displaces 1300cc's per combustion. You kept stating several times that "rotaries" have a value of 1.3 liters. This is wrong terminology, a rotary engine can come in several different sizes, just as normal piston engines come in different sizes. Yes, the mazda 13b is the most common.
So how much displacement from a 13b with 12a rotors? As you seemed to think that was possible a month ago.
Having owned six first-gen RX7s (and rebuilt a few rotaries) I'm in the 2.6L camp. The crank completes three rotations for every single rotation of both rotors. Therefore, each rotor fires on two of their three faces for every two rotations of the crank (eccentric) shaft - which is the same number of rotations required to complete the full cycle of a four-stroke engine, which the rotary definitely is. Since a total of four rotor faces produce a power "stroke" during these two eccentric shaft rotations we get 4 x 0.65L = 2.6L displacement. Incidentally, that works out to two power strokes per revolution for a two-rotor engine, the same as that of a 4-cylinder piston engine. But here's where things get interesting: The duration of the power stroke in a piston engine (as the piston is forced downward from TDC to BDC) is 180 degrees of crankshaft rotation. In a rotary, the duration of the power "stroke" is 240 degrees of eccentric shaft rotation - 50% longer than that of the piston engine. This provides a longer and smoother power delivery per power cycle, and the extra 50% in degrees of power stroke length is the equivalent of having an extra two cylinders (50% of four cylinders = 2 cylinders, 4 cylinders + 2 cylinders = 6 cylinders). That fact, combined with the absence of reciprocating components, is why the rotary runs as smoothly as it does.
Many thanks for this video. I have been pondering myself how to measure the true volume of a rotary engine. As you say in a 4 stroke cycle engine there are 4 components to that cycle. Now as the 4 stroke cycle in a rotary takes place in 360 degrees as opposed to a piston engine this takes place in 720 degrees. So we also have 3 chambers per rotor so i say that a rotary is similar to a 3 piston engine per rotor. So a twin rotor is actually similar to a 6 cylinder piston engine. So in a 2 rotor engine with 6 chambers of 650cc that makes it 3900 cc . If you then add that there are 2 firings in 720 cc compared to a piston you could consider the 2 rotor to actually be 7800cc for 720 degree cycle.
The other problem of a rotary compared to a piston is that in a piston the power stroke lasts 180 degrees but but in a rotary that is 90 degrees. So the work available is for a much shorter duration. The other problem is that a piston engine has a much larger Crank or lever moment so produces much more torque compared to a rotary. But will not rev a fast as a rotary.
I will admit to loving rotaries but never had the balls to actually buy one. I loved the RX8 R3 that i nearly bought a few years ago.
Hi random question when it comes to assembling the rotary engine using hylomar is the red 100 better than the universal blue
Citroen and Van Veen also experimented with Wankel, but only NSU and
Mazda had Wankel commercialized. A nice thought to rotate instead of the
existing up/down engines, but some bad hooks: bad compression control,
bad fuel consumption and bad CO2 creation.
All 3 faces should count towards total displacement. That being said its a 3.9L engine that you can pick up by yourself, so still a great innovation. Also makes up for the terrible MPG.
The most simple way to think about a rotary, in my opinion, is just to think of it as a 3 stroke. Simple and clear.
Why not compare BSFC between the rotary and some typical 1.3, 2.6 and 3.9L 4 stroke cycle engines? Obviously that doesn’t measure displacement and is meant as a measure of efficiency, but it might show where the rotary most closely resembles a 4 stroke reciprocating engine.
Here in California, the very first government agency was formed to
introduce motor vehicle emissions standards in 1967, still the strictest
air pollution standards in the world, Diesel fueled vehicles have
always been classified as clean, low emissions vehicles and were even
EXEMPT emissions regulations and the bi-annual testing program for 30
years. Yes, it is possible to observe something and still not understand
what you are seeing.. especially if you are not knowledgeable on the
issues.
ZERO TOLERANCE ON LEAKAGE
Man that was a great explanation. especially since I'm new to rotor engine.great job.
I'm reluctant to say that this notion really makes sense, even if that's how it's officially measured.
I'd say that an engine's displacement is best described as the volume available for one power stroke's fuel mixture, before compression, all "cyclinders" combined. (i.e. how much mixture could ideally be burnt per power stroke, if the engine was naturally aspirated). No crankshaft revolutions in this definition.
I believe the reason that it's 1.3L from factory as you stated is that 4 cycles happen on 1 E shaft rotation an as stated thats the amount of air expelled from 1 rotation. Equally understand that for comparison. The 2.6 makes more sense as piston takes the 2 rotations to complete the 4 cycles. But yeah people gonna hate if it's a 1.3, 2.6 or a 3.9. People always hate what they don't understand.... Loving the Cosmo BTW.
Why do they make so much power? They rev to the moon
I agree with everything this guys says, my friends V8 use just as much gas as me.
Wouldnt the rotary be a once stroke if it had one dorrito because it's all in one cycle, thus making a 2 rotor engine a two stroke?
I personally always say that the rotary is a 3-stroke since the Power stroke and exhaust stroke happen in the same movement.
Very well explained
Keep it coming really good vids and explanation!
Another great video!! Keep up the great work.
"dedicated to rotary" made me insta sub
This makes sense ... 2 rotations = 2.6L and 1 rotation = 1.3L ..... So I would be correct when saying that a 1.3L Rotory is equal to a 2.6L engine. .... air volume speaking.... yep it does make sense.... thanks for that good info ...
Exactly! It's equivalent to a 2.6L 4-cycle piston engine in terms of air volume. Notice the exact wording of this; I'm not saying that's it a 2.6L engine, merely that it's equivalent!
This makes so much more sense now. 24mpg from a 1.3L didn't make sense to me, but 2.6L is more understandable for the 24mpg figure. I think your right that the engine isn't a two cycle, but it still lubricates like one. It isn't really a true four cycle either. I'd just call it a Wankel cycle. Because Wankel stroke would be the butt of too many jokes.
Josh Bonds its a rotary because the dorito spins. Pistons stroke thats why theres seperate strokes. Back and forth vs constant rotation
+Taylor McCallum *Thank you Taylor, If we need a moron we'll call you.*
2-stroke Benz-Cycle 360° 4-stroke Otto-Cycle 720° 4-stroke Wankel-KKM 1080° *ARE YOU SURE? I THINK WE WILL CALL ON YOU* stupid
More videos like this please
how much fuel does it take compared with a skyline or ford six than you will have the true measurement
Each face would need to be counted as an individual cylinder.
A traditional piston can only have one cycle happening at once. In a rotary, when one face is in the Ignition cycle, one face is on intake and the other is exhaust, so it can have three happening at once. Also, from ignition to complete exhaust is a half turn of the crankshaft.
It is literally just a 3 cylinder engine in one object, therefore, if each face can house .65L of air, then each rotor would be equal to 1.95L, so a two rotor would be 3.9L (or a 3.9L 6 Cyl), a 3 rotor would be 5.85L (or a 5.85L 9Cyl), and a 4 rotor would be 7.8L (or a 7.8L 12 Cyl).
The traditional Engine Displacement definition can literally not be applied to a rotary, even if you replace "piston" with "rotor", because you would have to basically pretend the other two faces of the rotor aren't doing anything.
I propose a new definition: "Rotary engine displacement is the swept volume of all the rotors inside the rotor housings of a reciprocating engine in a single movement from Top Dead Centre (of the ignition stroke) to Bottom Dead Centre of the crankshaft times 3 (to account for the 3 faces of one rotor)."
It depends on how many rotors you have in my opinion, I would agree that each face is equivalent a cylinder...so all in all it's an awesome engine!!
Then why is it obsolete now?
evidence.
Anyone know what the Irish brokers rate the rotary against e.g. a 2 litre petrol or just a 1.3
Yes, basically, it's because the Wankel rotary engine's displacement isn't measured in the same way as a piston engine. If you measure a 6.2L LS3 the same way Mazda measured the 13b to end up with 1.3L an LS3 would be a 3.1L engine.
What many people have a hard time with is keeping the ENTIRE engine, all 6 faces of the rotors on a 13b, in mind at once along with the Wankel's 3:1 ratio. During operation, because there is a 3 to 1 ratio between the rotors and the eccentric shaft or e-shaft (equivalent to the crankshaft) that means for every 1 revolution of the e-shaft the rotors turn 120 degrees (1/3 of a revolution) which is the number of rotor degrees necessary to complete one phase on each rotor face. This results in 1 intake, one compression/power, and one exhaust PER rotor (although there is overlap because the second rotor is phased or "follows" the first for balancing reasons).
This means in 1 revolution of the e-shaft the entire engine's swept volume displacement is .65 * 3 faces * 2 rotors= 3.9L.
The main reason, I think, for this odd way of mesuringdisplacement that Mazda used that resulted in the 1.3L rating, only counting one rotor face per rotor, is because, esp. in Japan, insuring a 1.3L sports car is much cheaper than a 3.9L sports car as well as the fact that Japan has an absurd "displacement tax" so the smaller the rated displacement of the engine the better.
Internal Combustion Engines are known being linked to low Effective Compression Ratio, these first times because of poor quality of available gasoline. If changing the plug hole to an slot as Ernie Brink proposes, reduces greatly the Exhaust Gas Temperatures, this would mean a much higher Effective Compression
I approve this message . Now all I need is a rx8.
Ceasar Coleman you can have mine for £800 ☺
Hi 1st time viewer i gots a question can i drop 13b engine on a front wheel drive car?
Put a 13B on a dynamometer with an airflow meter. Run the engine at a known speed and measure the airflow. Calculate the volumetric efficiency. You can't get the same numbers saying that the engine displaces 1.3, 2.6, and 3.9 liters. Only one displacement will yield a vol eff number in the range of 100%. That would be 1.3 L. The other "displacements" would yield numbers of 50% and 33%.
The key detail is that the volumetric efficiency of an internal combustion engine is defined on the basis of mass air flow through one thermodynamic cycle. This is not only a function of piston displacement, but also of valves controlling the airflow. It takes two revolutions of the the crank in a 4-stroke engine to complete one thermodynamic cycle, but only one revolution of the camshaft. That's because it's the camshaft that controls the airflow.
All things considered I would say you should not compare it to 4 or 2 stroke. It's a rotary! For me a 4 stroke has to have valves. Thats why i also understand why people comepare it to 2 stroke specially when it comes to sound.
All Wankel KKM designs are 4-stroke...
Man that was so interesting you earned a sub :)
Ye I had an rx 8 for 10 lovely months b 4 it blew a seal due too cat failure, am also an engineer an I agree with the 2.6 litres as if you compare too a normal in-line 4 engine 2 crank revelations is what we would measure too then using the same amount makes for a more equal comparison 👍🏼
APEX SEAL LEAKS INSIDE THE ENGINE ON COMPRESSION STROKE THIS WHY YOU GET 80LBS ON A COMPRESSION CHECK THIS ENGINE IS 5 TO 1 RATIO WHEN IT LEAKS INSIDE THE ENGINE LOOKING FOR A 10 TO 1 ROTARY
az616578.vo.msecnd.net/files/2016/08/27/6360787077700554381193066848_Internet-Troll.jpg
Not just RX7 and RX8. The old Mazda cars are the best. Very big in drag racing and on the street. R100, RX2, RX3, RX4. You should change the title of this video.
RX3 coupes are the best and most valueable. The most sought after.
ERNIE BRINK THANK YOU FOR THE NEW HEMI WANKEL ENGINES CHEERS JUST THE FACTS
Well, over here in Belgium they are taxed like a 2.6L engine and I never knew why. I guess now I do.
Use the type of crank and piston ring type, which is better fuel.
Great video, makes perfect sense. 👍👍
ive been a rotary freak but i dont have the technical knowledge that you guys have.I had a nice swap with 12a on a 82Celica body and it moved. miss the torque and the beatiful music coming out of the exhaust.I wnna do another swap witha 20b when im finacialy stable.Great coments with the wankel engine and keep more videos coming.
by the way I cant wait to see the RX9 in the Chicago Auto Show .
Happy Holidays
COSMO SUPER CAR IS ON THE BURNER AWESOME THANK YOU ROBERT DAVIS AND MAZDA 2019
so, only one rotar displaces 650cc of volume, so a 2 rotar engine displaces 2600cc of displacement?
When asking why a small displacement engine can make big power, it's because displacement is irrelevant. What is relevant is airflow, because an engine is an airpump. That's why the same engine with different heads, cams, etc makes different amounts of power.
Yes you are correct but NOT different amount of torque ....an NA 13B is nowhere close a 2.6L in torque let alone a 3.9 Lit. So rotary (in real life not calculations) is equivalent to 2-2.2 piston in power and torque ....... and nobody actually bothered to answer HOW is the capasity of the 0.65 lit measured..... is all the "air"/"water" one housing can include or one rotor face..... from WHAT degrees up to what degrees? .....
Welll done man! I love these videos
I have compaired the 2 roter to a v6. Same number of "cylinder's" so yeah 3.9L. Except for the number of power strokes which is the same as a v8, two per one revolution. No wonder people get confused about the rotary.
Your explanation is wrong though. "Engine displacement is the swept volume of all the pistons inside the cylinders of a reciprocating engine". Problem is, the rotary doesnt have pistons and it is not a combustion engine with reciprocating motion. The rotors are basically the "pistons" on the Wankel engine. In a four stroke, two full revolutions of the crankshaft are required for all the pistons to have fired at least once. In the Wankel engine, for each revolution of the e-shaft, two faces fire at the same time. If I go by your logic, that would mean the rotary needs 3 revolutions of the e-shaft for all the faces to fire and not one, so the bond with the 2 stroke engine kinda goes away. It is hard to really understand the displacement of a rotary, but you got it wrong. The difference lies in your example. A 4 cyl four stroke has four combustion chambers, so you need all the four pistons to fire at least once for you to know how much air got into each combustion chamber. So if two pistons fired once, the other still have to, so you can't tell the displacement until then. On a rotary, there are two combustion chambers. All six faces have 654cc. But only two of them, one per rotor, for each revolution, has a power stroke. In one of the rotors, if face number 2 let's call it, has a power stroke, face number one is the intake stroke and face number two is in the exhaust stroke. But don't misunderstand this. Even if I said the faces were on some "strokes", you shouldn't treat them as pistons. That is the tricky part. But you don't consider exactly how MUCH air the engine is taking. If by one single revolution, in the 4 cyl, only half of the maximum intake of air has gone into the engine, in the rotary, in one single revolution, the maximum air intake has already been reached, which, in the case of the 13B, is 1.3L. You just keep adding air for all the six faces as if the engine could take more than 1.3L, you're just repeating the cycle. The reason for all the power of a rotary is indeed because of how fast each power stroke succeeds one another.
DoubleC I’ve been waiting for so long to witness someone who actually had crunched the numbers & finally fathomed the answer!
DoubleC thanks for the input
DoubleC. Make a video and post u are accurate
3.9 liter
*Sorry, but the Wankel KKM IS A 4-STROKE so we calculate displacement at 1080° NOT 360°*
*Its not that difficult to understand... each orbiting piston(rotor) has 3 sides forming 3 combustion chamber volumes, each with a swept volume of 654cc. times the 2 housings is 6 and equaling 3,924cc.*
*The other important thing that people without formal engineering experience fail to understand is that a 4 cycle Otto or Diesel engine completes its firing sequence in 720° of crankshaft rotation while the 4-cycle Wankel KKM designs required 1080° of rotation to complete its firing sequence...*
*These two important and often misunderstood details are the basis of the commonly used "2X" conversion formula for accurately "comparing" the displacement of the Wankel with other designs..*
*_Any questions? I would be happy to explain in more detail..._*
Wouldn't it be more of a 1 stroke and nothing even similar to a2 or 4 stroke just because all events are separate how does that make it 4 Stroke. When it does all 4 events in 1 cycle?please explain
*All Wankel engines use the same 4-stroke operating principle as the Otto engine, each of the 3 combustion faces goes through the 4 cycles separately just like a reciprocating engine does.*
I think it goes back to the fact that mazda wanted it to be under 1.5L so that japenese consumers would be taxed less. Since their was an additional tax for owning a car that displaced greater than 1.5L back in the day for Japan
Someone shoulda further developed the rotary. Think about it, a 2 rotor engine has 3 moving parts, not much friction really and you could make higher compression rotors. Oil injection with the fuel would also help a lot with wear cos the fuel goes everywhere in the intake stroke and gets spread in the housings and irons. Youre gonna say something about pollution but put a DPF on it or rather an RPF(rotary particulate filter) and youd have clean emissions. Just a thought
Good educational vid, bt I count it that there is an ignition event every 120 of 360 degrees of the eccentric shaft, mayb it'd be easier to explain with a single rotor engine
There is an ignition event every 120 degrees, however, the full cycle is only completed on face per rotation.
Actually, there’s a combustion event every *180* degrees of e-shaft rotation. Very much like a 4 cyl. On older Rotaries that had a single dual-post (wasted spark) coil for leading ignition, you could run the engine leading only on most standalone EMSs by setting it up as a 4 cylinder 4 stroke with a single ignition output (like a distributor) and then just hook the single output to the leading coil. 4-cylinder engines have a combustion event every 180 degrees. IF you look at an actual e-shaft, the lobes are offset by 180 degrees as well.
GOD BLESS YOU DOKOTRBIMMER
I clicked on this video because the heading said "The SECRET Behind Why RX7 and RX8 Rotary Engines Make SO Much Power". Not how a rotory works in difference to a piston engine, I am still none the wiser. I wish people would reference their videos appropriately!
Well, its kinda of joke really... "SO Much power" makes me laugh!
Great video 👍
I wish more and more people got into rotarys
To keep them alive
Unfortunately the Wankel engine is obsolete now, no longer produced anywhere in the world... and very quickly becoming extinct.
doktorbimmer it’s making a come back next year in Mazda’s hybrid car.
Just don’t know if it’s going to be the motor that was in the rx8 or rx7
*No, it is not coming back. Despite all the fake clickbait rumors on the automotive blogsites, Mazda discontinued development of Wankel engines in May 2009 and has permanently ceased all production.*
*Mazda's CEO has stated officially that the company has no plans to resume any production and there is absolute zero evidence to prove otherwise.*
doktorbimmer are you sure brother I know they stopped after the rx8
But read that it will be back in the Mazda Ev
Let’s look it up
*Mazda and Toyota have only confirmed a joint project with Denso to built zero-emission battery electric vehicles to comply with new laws in California and 11 other states.*
*Both companies recently lost a bid to allow range extenders and hybrids under the new law that went into effect this year..
If Mazda does not offer a zero emissions car by 2023 it will be banned from selling any cars in California (Mazda's largest and most profitable market).*
I see lots of people sell their rx8 and say it is 2.6L did they made some of those??
No. Rx8 are all 1.3L 2-rotor 13b-msp.
just started what I figure will take me about 7 years to finish 3 Rotor FB
great info when you line up a apex in the leading plug hole you see two chambers at the same time HEAT IS NO GOOD so two keep your turbo and engine in great shape you must stop the flames that are inside the engine before it ever comes out of the housings
So you're saying its like an "all stroke" in a way?
Great video, thankyou
Every car guy should have a rotary in their car collection!... Car guys have at least 3 cars!
...Wife car count!... IF you're doing the mechanical work in it!... 😎👍
1.3L makes perfect sense if you will stop bashing those of us that maintain that the rotary engine is really a two stroke. A 4 stroke engine uses a full stroke (piston at TDC to BDC) for each phase, intake, compression, power, exhaust. While a two stroke technically has all 4 phases, but each phase only takes 1/2 of a stroke. A single piston 4 stroke engine fires once every 2 revolutions, while a 2 stroke fires every revolution. A rotary engine fires every revolution making it a 2 stroke engine.
Remember, a stroke is 1/2 rotation of the crankshaft, not a phase described as intake, comp, power, exhaust. In a 4 stroke engine the strokes are thus named because each phase uses a single stroke, but don't project that naming convention to the stroke.
The definition of the word stroke = "noun
1. an act of hitting or striking someone or something; a blow."
You description gets confusing because of your initial assumption that the rotary is a 4 stroke. If you assume that the rotary is a 2 stroke, it all works out nicely. Nothing confusing about it.
And as we all know, 2 strokes make more power / displacement than a 4 stroke, simply because it fires twice as often!
*All Wankel KKM designs are 4-stroke...*
*The Mazda 13B requires 3 shaft revolutions to complete all 4 strokes in each chamber face... 3 turns equal 3.9 liter of total air displaced.*
how do i gain more torque on a rotary wankel reciprocating engine.?
trying to figure this out myself.....so far...more compression doesn't help....only good answer is add a rotor...
.no replacement for displacement
take a sip of water lol
The rotary engine's biggest secret...SHORT LIFE SPAN...
Good explanation 👍