Renesis a 2.6L
04-03-2003, 01:19 PM
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Renesis a 2.6L
Has anyone else read the technobabble article in the new SCC? Dave Coleman is trying to convince the readers that the 13B and Renesis are 2.6L. He puts up some good points, like breathing volume, but I still believe he's wrong. True the engines can hold 2.6L of air, but there is no way that more than two combustion chambers can fire at once. A piston engine, however, could theoretically fire all cylinders at once with a custom crankshaft. Anyone else have any other points?
04-03-2003, 01:42 PM
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What's SCC? I have the May issue of Sports Car International where a David Colman did a test of the RX-8 but I didn't notice anything in the article about it really being a 2.6L.
04-03-2003, 01:46 PM
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It's Sport Compact Car. Read technobabble in the front of the magazine. It's about the rotories being twice as big as stated, and abou the next RX-7.
04-03-2003, 03:03 PM
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The dude is correct.
The engine has a swept capacity of 654cc per rotor, so both rotors together are 1308cc. That is it's swept volume.
In a rotary you get one power pulse per rotor per eccentric shaft revolution, the same as a two stroke engine (ever wondered why they race 500cc two stroke and 1000cc four stroke bikes in Moto GP up antil last year? Because they have the same working volume). So it's working volume is effectively double that of a normal four stroke piston engine of the same swept volume.
In a piston engine you only get one power pulse per piston every two revolutions.
Look at it this way.
1. Piston at top dead centre. Inlet valve opens, half a crank turn piston is at bottom dead centre. 1st stroke.
2. Piston goes from BDC to TDC compressing the air and fuel mixture. 2nd stroke.
3. At about TDC the mixture is ignited and the piston is pushed down by the force of the igniting air and fuel mixture and goes to BDC again. 3rd stroke.
4. The exhaust valve opens as the piston goes back to TDC pushing the exhaust gas out of the cylinder. 4th stroke.
No matter how you configure a piston engine crank, you will still only get one power pulse per piston per revolution from a four stroke engine as the crankshaft has to rotate two complete times for the engine to go through induction, compression, expansion and exhaust cycles.
This is why the engine, although going through the normal four cycles (cycles, not strokes it must be remembered) of induction, compression, expansion and exhaust, is actually like a two stroke in the way in which it opperates.
In simple terms the Rotary engine is a four cycle two stroke.
The engine has a swept capacity of 654cc per rotor, so both rotors together are 1308cc. That is it's swept volume.
In a rotary you get one power pulse per rotor per eccentric shaft revolution, the same as a two stroke engine (ever wondered why they race 500cc two stroke and 1000cc four stroke bikes in Moto GP up antil last year? Because they have the same working volume). So it's working volume is effectively double that of a normal four stroke piston engine of the same swept volume.
In a piston engine you only get one power pulse per piston every two revolutions.
Look at it this way.
1. Piston at top dead centre. Inlet valve opens, half a crank turn piston is at bottom dead centre. 1st stroke.
2. Piston goes from BDC to TDC compressing the air and fuel mixture. 2nd stroke.
3. At about TDC the mixture is ignited and the piston is pushed down by the force of the igniting air and fuel mixture and goes to BDC again. 3rd stroke.
4. The exhaust valve opens as the piston goes back to TDC pushing the exhaust gas out of the cylinder. 4th stroke.
No matter how you configure a piston engine crank, you will still only get one power pulse per piston per revolution from a four stroke engine as the crankshaft has to rotate two complete times for the engine to go through induction, compression, expansion and exhaust cycles.
This is why the engine, although going through the normal four cycles (cycles, not strokes it must be remembered) of induction, compression, expansion and exhaust, is actually like a two stroke in the way in which it opperates.
In simple terms the Rotary engine is a four cycle two stroke.
04-03-2003, 03:15 PM
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Originally posted by Dazz
This is why the engine, although going through the normal four cycles (cycles, not strokes it must be remembered) of induction, compression, expansion and exhaust, is actually like a two stroke in the way in which it opperates.
In simple terms the Rotary engine is a four cycle two stroke.
This is why the engine, although going through the normal four cycles (cycles, not strokes it must be remembered) of induction, compression, expansion and exhaust, is actually like a two stroke in the way in which it opperates.
In simple terms the Rotary engine is a four cycle two stroke.
04-03-2003, 06:09 PM
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Originally posted by Dazz
This is why the engine, although going through the normal four cycles (cycles, not strokes it must be remembered) of induction, compression, expansion and exhaust, is actually like a two stroke in the way in which it opperates.
In simple terms the Rotary engine is a four cycle two stroke.
This is why the engine, although going through the normal four cycles (cycles, not strokes it must be remembered) of induction, compression, expansion and exhaust, is actually like a two stroke in the way in which it opperates.
In simple terms the Rotary engine is a four cycle two stroke.
04-03-2003, 06:37 PM
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The way I look at it is. 250cc bikes are still call 250cc bikes regardless of whether it is a 2 stroke or 4 stroke. The fact that it takes twice the displacement for a 4 stroke to compete with a 2 stroke, doesn't seem to make any difference in the motorcycle community, they still call the 250's, 250's. I will continue to call the 13b a 1.3 liter. I don't feel i should have to call my 1.3 liter car a 2.6 liter, just because it is twice as efficient as a 4 stroke piston engine.
04-03-2003, 06:39 PM
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Your missing the point and are getting it **** about.
The humble four stroke piston engine is by far the most widely used engine for automotive purposed, and thus every other engine will be compared to it.
In this instance, the author is correct in stating that the 13B is the equal of a 2.6 litre piston engine.
If you wanted to argue the point, it could be stated that a four stroke engines capacity should be halved to reflect it's actual working volume. Thus a 2.6 litre piston engine would be refered to as a 1.3 litre engine.
The result would then be you would compare a 13B at 1308cc to a 1300cc four stroke piston engine.
So whether you compare a 13B as a 2.6 litre Rotary (working capacity) to a 2.6 litre piston engine (cylinder capacity) or a 13B as a 1.3 litre Rotary (chamber capacity) to a 1.3 litre piston engine (working capacity) it is exactly the same.
The bottom line is, at any given rpm, a 1.3 litre rotary engine at 100% volumetric efficiency will inhale the same amount of air as a 2.6 litre four stroke piston engine attaining 100% volumetric efficiency.
The humble four stroke piston engine is by far the most widely used engine for automotive purposed, and thus every other engine will be compared to it.
In this instance, the author is correct in stating that the 13B is the equal of a 2.6 litre piston engine.
If you wanted to argue the point, it could be stated that a four stroke engines capacity should be halved to reflect it's actual working volume. Thus a 2.6 litre piston engine would be refered to as a 1.3 litre engine.
The result would then be you would compare a 13B at 1308cc to a 1300cc four stroke piston engine.
So whether you compare a 13B as a 2.6 litre Rotary (working capacity) to a 2.6 litre piston engine (cylinder capacity) or a 13B as a 1.3 litre Rotary (chamber capacity) to a 1.3 litre piston engine (working capacity) it is exactly the same.
The bottom line is, at any given rpm, a 1.3 litre rotary engine at 100% volumetric efficiency will inhale the same amount of air as a 2.6 litre four stroke piston engine attaining 100% volumetric efficiency.
04-03-2003, 07:33 PM
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QUOTE]Originally posted by justinm2
I don't feel i should have to call my 1.3 liter car a 2.6 liter, just because it is twice as efficient as a 4 stroke piston engine. [/QUOTE]
Yes but then it is hard to justify why your 1.3 litre engine consumes so much more fuel than a normal 1.3 litre engine!
You don't have to call it a 2.6 litre, it is a 1.3 litre engine, but it's equal to a 2.6 in the way it opperates.
And with the bikes, yes they called the 500's 500's, but they raced them with 1000cc four strokes becasue that was what they were equal too, and anyone who knows about bike racing understands about two stroke vs four stroke.
Average people in the automotive world (your normal car owners) are not really aware of how a two stroke opperates (most don't understand how a four stroke opperates) so for the purpose of comparisons so people can begin to understand how things work, you must present the facts as they are.
If you must, call it a 1.3 litre two stoke and then you have your bases covered nicely.
I don't feel i should have to call my 1.3 liter car a 2.6 liter, just because it is twice as efficient as a 4 stroke piston engine. [/QUOTE]
Yes but then it is hard to justify why your 1.3 litre engine consumes so much more fuel than a normal 1.3 litre engine!
You don't have to call it a 2.6 litre, it is a 1.3 litre engine, but it's equal to a 2.6 in the way it opperates.
And with the bikes, yes they called the 500's 500's, but they raced them with 1000cc four strokes becasue that was what they were equal too, and anyone who knows about bike racing understands about two stroke vs four stroke.
Average people in the automotive world (your normal car owners) are not really aware of how a two stroke opperates (most don't understand how a four stroke opperates) so for the purpose of comparisons so people can begin to understand how things work, you must present the facts as they are.
If you must, call it a 1.3 litre two stoke and then you have your bases covered nicely.
04-08-2003, 04:15 PM
#12
Hey Dazz not to argue about your opinion but it does make since. However, I personally will not classify it as a 2.6 liter untill Mazda does.
On a side note, The piston engine still haves an advantage when it comes to the number of power strokes it can have in relation to its crank shafts 2 rotations. We all know that rpm measurments are taken from each revolution of the crank shaft and e-shaft. With that in mind, think about this, for every two revolutions of the e-shaft, a 2 rotor will only have 4 power strokes. Thats comparible to a 4 cyl. However it takes 3 revolutions of the e-shaft for all the rotors to circle once. Therefore a 6 cyl will have more power strokes ( 6 total for every 2 rotations)as well as an 8cyl( 8 total for every 2 rotations). Though it may appear that the piston engine has a power advantage, the rotory in general has always produced more hp per liter than pistons. This is the reason why I love the rotory so much. :D
On a side note, The piston engine still haves an advantage when it comes to the number of power strokes it can have in relation to its crank shafts 2 rotations. We all know that rpm measurments are taken from each revolution of the crank shaft and e-shaft. With that in mind, think about this, for every two revolutions of the e-shaft, a 2 rotor will only have 4 power strokes. Thats comparible to a 4 cyl. However it takes 3 revolutions of the e-shaft for all the rotors to circle once. Therefore a 6 cyl will have more power strokes ( 6 total for every 2 rotations)as well as an 8cyl( 8 total for every 2 rotations). Though it may appear that the piston engine has a power advantage, the rotory in general has always produced more hp per liter than pistons. This is the reason why I love the rotory so much. :D
04-15-2003, 05:57 PM
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i'm gonna reley on my good0old friend math for this one.
each chamber displaces 654cc.
There are two chambers
654 x 2= 1308cc, which is equal to 1.3 litres.
the main difference is there are 6 chambers, however. But the wonderful Renesis rotary engine can not fire more than 2 chambers at once, so at one time it's displacement can NEVER exceed 1308cc. if a piston engine was outfitted with a custom crankshaft, it could, in theory, displace all it's volume, but they don't under normal conditions. I don't care what you say, there is NO WAY the Renesis could displace 1.3L at one time.
each chamber displaces 654cc.
There are two chambers
654 x 2= 1308cc, which is equal to 1.3 litres.
the main difference is there are 6 chambers, however. But the wonderful Renesis rotary engine can not fire more than 2 chambers at once, so at one time it's displacement can NEVER exceed 1308cc. if a piston engine was outfitted with a custom crankshaft, it could, in theory, displace all it's volume, but they don't under normal conditions. I don't care what you say, there is NO WAY the Renesis could displace 1.3L at one time.
04-15-2003, 07:23 PM
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Originally posted by mrWankel
i'm gonna reley on my good0old friend math for this one.
each chamber displaces 654cc.
There are two chambers
654 x 2= 1308cc, which is equal to 1.3 litres.
the main difference is there are 6 chambers, however. But the wonderful Renesis rotary engine can not fire more than 2 chambers at once, so at one time it's displacement can NEVER exceed 1308cc. if a piston engine was outfitted with a custom crankshaft, it could, in theory, displace all it's volume, but they don't under normal conditions. I don't care what you say, there is NO WAY the Renesis could displace 1.3L at one time.
i'm gonna reley on my good0old friend math for this one.
each chamber displaces 654cc.
There are two chambers
654 x 2= 1308cc, which is equal to 1.3 litres.
the main difference is there are 6 chambers, however. But the wonderful Renesis rotary engine can not fire more than 2 chambers at once, so at one time it's displacement can NEVER exceed 1308cc. if a piston engine was outfitted with a custom crankshaft, it could, in theory, displace all it's volume, but they don't under normal conditions. I don't care what you say, there is NO WAY the Renesis could displace 1.3L at one time.
04-15-2003, 07:28 PM
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Originally posted by Dazz
QUOTE]Originally posted by justinm2
I don't feel i should have to call my 1.3 liter car a 2.6 liter, just because it is twice as efficient as a 4 stroke piston engine.
QUOTE]Originally posted by justinm2
I don't feel i should have to call my 1.3 liter car a 2.6 liter, just because it is twice as efficient as a 4 stroke piston engine.
Yes but then it is hard to justify why your 1.3 litre engine consumes so much more fuel than a normal 1.3 litre engine!
You don't have to call it a 2.6 litre, it is a 1.3 litre engine, but it's equal to a 2.6 in the way it opperates.
-1998 nissan 240sx/2.4l/160ft-lbs
-2003 subaru impreza 2.5rs/2.5l/166ft-lbs
-2003 mitsubishi galant/2.4l/155ft-lbs
I am aware these are all just four cylinder engines and not six, but i'm just trying to show why i agree with dazz and believe the 13B should be, but probably won't be, considered a 2.6l engine.
04-15-2003, 08:14 PM
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everyone knows it breathes twice as quick as a 4stroke... racing governing bodies, racers, engineers, everyone... it's nothing new, but is IS a 1.3L engine, which is COMPARABLE to a 2.6L engine.
... i like how the RENESIS stacks up against those 4 bangers of very equal displacement!!
...
i like how the RENESIS stacks up against those 4 bangers of very equal displacement!!
04-15-2003, 09:20 PM
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What I find hard to believe, is the total lack of mechanical knowledge some people have yet still profess to know more than those who actually understand how things work.
The engine has a single chamber capacity of 654cc. So with two rotors it is 1308cc. It's capacity is 1308cc.
So, the engine is a 1.3 litre.
HOWEVER, now pay attention here people.
Because it has one power stroke per rotor per revolution of the eccentric shaft, as opposed to one power stroke per piston per two revolutions of the crankshaft in a piston engine, it physically inhales the same amount of air as a 2.6 litre piston engine at the same rpm.
The engine is a 1308cc two stroke, which makes it the "equivelant" of a 2.6 litre four stroke. What is so hard to understand?
Yes the engine is a 1.3 litre in swept volume, but when it opperates, it behaves, in conventional engine terms, as a 2.6 litre.
So it is a 1.3 litre engine, that compares in opperational displacement to a 2.6 litre engine.
It can't be any simpler than that. If you chose to believe that it is equal to a 1.3 litre piston engine then you are obviously stupid!
Sorry if that offends anyone, but the biggest enemy of the Rotary engine are all of the so called and self professed experts who continue to talk rubbish and make it harder for those who actually know and understand to tell it the way it is.
The engine has a single chamber capacity of 654cc. So with two rotors it is 1308cc. It's capacity is 1308cc.
So, the engine is a 1.3 litre.
HOWEVER, now pay attention here people.
Because it has one power stroke per rotor per revolution of the eccentric shaft, as opposed to one power stroke per piston per two revolutions of the crankshaft in a piston engine, it physically inhales the same amount of air as a 2.6 litre piston engine at the same rpm.
The engine is a 1308cc two stroke, which makes it the "equivelant" of a 2.6 litre four stroke. What is so hard to understand?
Yes the engine is a 1.3 litre in swept volume, but when it opperates, it behaves, in conventional engine terms, as a 2.6 litre.
So it is a 1.3 litre engine, that compares in opperational displacement to a 2.6 litre engine.
It can't be any simpler than that. If you chose to believe that it is equal to a 1.3 litre piston engine then you are obviously stupid!
Sorry if that offends anyone, but the biggest enemy of the Rotary engine are all of the so called and self professed experts who continue to talk rubbish and make it harder for those who actually know and understand to tell it the way it is.
04-16-2003, 12:05 AM
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Originally posted by Dazz
What I find hard to believe, is the total lack of mechanical knowledge some people have yet still profess to know more than those who actually understand how things work.
What I find hard to believe, is the total lack of mechanical knowledge some people have yet still profess to know more than those who actually understand how things work.
The engine is a 1308cc two stroke
Just giving you a hard time, but the rotary has a four stroke combustion cycle.
04-16-2003, 12:19 AM
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And once again .............
Do you know the difference between a stroke and a cycle?
A rotary engine is a 4-cycle (induction, compression, power, exhaust) 2 stroke (one power stoke per rotor/piston per revolution of eccentric/crank shaft).
Do you know the difference between a stroke and a cycle?
A rotary engine is a 4-cycle (induction, compression, power, exhaust) 2 stroke (one power stoke per rotor/piston per revolution of eccentric/crank shaft).
04-16-2003, 02:59 AM
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you better go tell these people they're wrong then http://travel.howstuffworks.com/rotary-engine4.htm .
"Rotary engines use the four-stroke combustion cycle, which is the same cycle that four-stroke piston engines use."
"Rotary engines use the four-stroke combustion cycle, which is the same cycle that four-stroke piston engines use."
04-16-2003, 05:06 AM
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That's right, they use the four stroke "cycle", it does not say that they are a four stroke, are you too unable to tell the difference!
Heard the saying "there are none so blind as those who will not see?"
Heard the saying "there are none so blind as those who will not see?"
04-16-2003, 10:56 AM
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Sputnik, lock this please, it's a silly conversation.
it's a simple fact: Dazz is right (as always).
it's a 1.3L static displacement engine, which happens to have a two stroke (read ONE FULL 4-STROKE CYCLE) capacity of 2.6L... this is because a wankel will have one power stroke per e-shaft (which is analogous to the crankshaft in a piston engine) revolution, as opposed to one every TWO revs in the 4-stroke piston engine.
the wankel is a little different as it combines the two: it has all four otto cycle phases, but it does all four in ONE revolution of the e-shaft.
cut it anyway you like, that's it. we say 2-stroke bikes with 50cc's of static displacement are 50cc bikes, but they run with the 100cc 4-strokes: it's not a difficult concept. end of discussion... we're only repeating ourselves.
it's a simple fact: Dazz is right (as always).
it's a 1.3L static displacement engine, which happens to have a two stroke (read ONE FULL 4-STROKE CYCLE) capacity of 2.6L... this is because a wankel will have one power stroke per e-shaft (which is analogous to the crankshaft in a piston engine) revolution, as opposed to one every TWO revs in the 4-stroke piston engine.
the wankel is a little different as it combines the two: it has all four otto cycle phases, but it does all four in ONE revolution of the e-shaft.
cut it anyway you like, that's it. we say 2-stroke bikes with 50cc's of static displacement are 50cc bikes, but they run with the 100cc 4-strokes: it's not a difficult concept. end of discussion... we're only repeating ourselves.
04-16-2003, 12:19 PM
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Wakeech,
I respectfully disagree. Just because there is disagreement doesn't mean that the thread should be closed. If you close the thread before there is a resolution, then there will be lots of people who believe the wrong thing. With lots of people believing the wrong thing, there are bound to be more threads like this in the future.
Instead, I would rather just work it out now so people can reference a this complete thread in the future, rather than having to search through all the little threads that popped up and got closed.
I respectfully disagree. Just because there is disagreement doesn't mean that the thread should be closed. If you close the thread before there is a resolution, then there will be lots of people who believe the wrong thing. With lots of people believing the wrong thing, there are bound to be more threads like this in the future.
Instead, I would rather just work it out now so people can reference a this complete thread in the future, rather than having to search through all the little threads that popped up and got closed.