What does it mean for an RX8 to be rotory powered?

[Zenmervolt]

Originally posted by: SagaLore

Originally posted by: Marlin1975

Originally posted by: SagaLore

Originally posted by: Skoorb
In regards to better or worse I'd say that it's pretty clear that, overall, it's an inferior engine. There has been many years to research and "perfect" (within reason) the rotary engine and mazda remains the only manufacturer to put one in their consumer vehicle. In fact until the new RX8 they weren't even using rotaries for a while (since RX7 had stopped production for a while). There is obviously some novelty marketing going on with the rotary engine. A person can buy an Rx8 and know that nobody else is buying a new car with a rotary, so that's definitely an attractition. Yes, it's lighter than a conventional, but hardly any cars use them, whether you're talking about a commuter car, a race car, or a drag car. They just aren't as good, although they are not CRAP and they do still work decently and can be made at a fairly competitive price, as mazda has done with the RX8. Objectively I still think that the 350z would be a better bang for buck, but the rotary is different which makes it fairly neat.

LIAR! :|

It's just underdeveloped, that is all. The piston engine has been by far longer researched and built, way back since steam engines. The engine market still has a quite a lot of propoganda built into it - my old high school science teacher had a brother that patented a new fuel system that gave engines (back in the day) 200 miles to the gallon, but an engine company bought it off him and then shelved it permanently.

Actually no you aren't a liar. Sorry. The DKM model (RX7 rotary) wasn't Wankel's original design. He prefered the KKM model because the housing also rotated at 2/3 the speed the same direction as the rotar. His development partner forced the team to go with the stationary (DKM) model because it could be smaller without an extra housing (and spark plugs were stationary), however, the KKM had huge performance abilities and could excel speeds above 15k rpm with almost no vibration.

I also believe with today's technology and know-how, a diesel compressed gasoline injected KKM wankel would be the ultimate engine. You could do away with the cooling system and just add heatsink to the rotating housing for air cooling. You could have a series of rotor chambers with different sizes and gearing speeds to cascade the air intake compression and exhaust expansion. Like they use to do with auxiallary steam pistons to regain energy efficiency.

That myth is junk. You can get a copy of the patent and try it yourself, it NEVER worked. Geeze gotta love the idiots that believe anything they read or hear.

Ummm no, it is not anything you've read or heard. My physics teacher was not telling me an urban legend.

Unfortunately the energy density of gasoline and diesel, along with the laws of physics, prove you wrong.

ZV

 

wants to go to school and become an (I.C.E. specific..) Engineer

I took those classes Eli, they are pretty damn good

 

[Eli]

Originally posted by: Roger

wants to go to school and become an (I.C.E. specific..) Engineer

I took those classes Eli, they are pretty damn good

Really? Cool.. I want to take them not only for the knowledge, but I would like to actually be on the R&D team for a company. I think that'd be a pretty awesome job.

 

[apoppin]

Originally posted by: Roger

My 1976 RX5 (Cosmo) has a 13B rotary engine - 1.3 L and produces almost 300hp without turbocharging.

Really ?

Care to rephrase that statement ?

Really!



and no.

edit (rephrase it, no - explain it, maybe: the displacement is 1.3L. The hp produced with a big carb and headers with smog disconnected (only 1 functioning spark plug per chamber, not 2) is almost 300. Clearer?

edited again . . . oh yeah, the chamber is polished and mildly ported . . . BTW, I did the work rebuilding it myself - piece of cake - and the engine is so light, 2 people can lift it out of the engine compartment.

I like rotaries.

 

[SagaLore]

Check out this new engine design:

Five Stroke

 

[Eli]

Originally posted by: SagaLore
Check out this new engine design:

Five Stroke

Without looking at the site, it is the "extended combustion" design you spoke of, correct?

 

[SagaLore]

Originally posted by: Roger

You are bitter.

You are not too bright.

 

[Zenmervolt]

Originally posted by: Eli

Originally posted by: Roger

wants to go to school and become an (I.C.E. specific..) Engineer

I took those classes Eli, they are pretty damn good

Really? Cool.. I want to take them not only for the knowledge, but I would like to actually be on the R&D team for a company. I think that'd be a pretty awesome job.

I have a feeling that you'll be very good at it.

ZV

 

[Eli]

Originally posted by: Eli

Originally posted by: SagaLore
Check out this new engine design:

Five Stroke

Without looking at the site, it is the "extended combustion" design you spoke of, correct?

Hmm.. Not sure if it was what you were referring to or not.

That is definately an interesting design for a diesel engine. Wonder if we'll ever see anything come from them, or something similar...

It seems hard to find any inherent flaws, because it is just an extensive modification of current diesels. Of course, the questions would be.. how reliable is the so called "combustion shaft".. it seems it would be taking a great deal of abuse..

Interesting though.

EditReading more.. So this thing needs 2 pistons per "bank", one for induction and compression, and one for power and exhaust? And it still manages to be more efficient than a conventional diesel? Wow..

Or do both pistons cycle through their jobs? Hmm..

I wish they had a (good) animated gif of the complete cycle. The only one I've seen is jumpy and hard to follow.

 

[SagaLore]

Originally posted by: Eli

Originally posted by: SagaLore
Check out this new engine design:

Five Stroke

Without looking at the site, it is the "extended combustion" design you spoke of, correct?

No I just came across this one. This one extends the combustion before it's released into the chamber. What I mentioned before just extended the stroke.

I'm looking for it now... it might be the Miller Cycle engine, but I don't think it involved a supercharger...

 

[SagaLore]

Originally posted by: Eli

Originally posted by: Eli

Originally posted by: SagaLore
Check out this new engine design:

Five Stroke

Without looking at the site, it is the "extended combustion" design you spoke of, correct?

Hmm.. Not sure if it was what you were referring to or not.

That is definately an interesting design for a diesel engine. Wonder if we'll ever see anything come from them, or something similar...

It seems hard to find any inherent flaws, because it is just an extensive modification of current diesels. Of course, the questions would be.. how reliable is the so called "combustion shaft".. it seems it would be taking a great deal of abuse..

Interesting though.

I would guess less abuse than a typical cylinder, because there are no moving parts inside it, so no extra friction. Since it's a solid cylindrical mass, it should be sturdy enough for that kind of internal pressure, not sure about heat buildup though.

 

[SagaLore]

I remember seeing this one a few years ago, looks like they've made some progress.

TRICE engine

Hmm... did I accidentally hijack this thread?

 

[Eli]

Originally posted by: SagaLore

Originally posted by: Eli

Originally posted by: Eli

Originally posted by: SagaLore
Check out this new engine design:

Five Stroke

Without looking at the site, it is the "extended combustion" design you spoke of, correct?

Hmm.. Not sure if it was what you were referring to or not.

That is definately an interesting design for a diesel engine. Wonder if we'll ever see anything come from them, or something similar...

It seems hard to find any inherent flaws, because it is just an extensive modification of current diesels. Of course, the questions would be.. how reliable is the so called "combustion shaft".. it seems it would be taking a great deal of abuse..

Interesting though.

I would guess less abuse than a typical cylinder, because there are no moving parts inside it, so no extra friction. Since it's a solid cylindrical mass, it should be sturdy enough for that kind of internal pressure, not sure about heat buildup though.

Well, the "combustion shaft" rotates, so there's friction somewhere.. the ports on the combustion shaft have to match up with the ports above the pistons, so there's going to be friction there..

That's kinda what I meant. It kinda sucks that any drastic engine design change probably isn't going to be embraced too well, unless it is truely revolutionary. We've managed to get our engines pretty damn reliable.

Adding more moving parts almost seems like a step in the wrong direction. I think at this point, we need better materials.

 

[Eli]

Originally posted by: SagaLore
I remember seeing this one a few years ago, looks like they've made some progress.

TRICE engine

Hmm... did I accidentally hijack this thread?

Yeah, I've seen that one..... kinda bizzare.

 

[apoppin]

Originally posted by: Skoorb

Originally posted by: wasssup
how reliable are those old RX-7's by now? (the early 90's FC's, non-turbo)? sounds like a nice cheap way to get into the rotary club, but i dunno how those engines stood the test of time..

Well let's just say I hope you have a ready savings account to cover repairs

My gues would be a hybrid powered car (gas and electricity). You could get 200 MPH with todays tech that way. This is still going?

There was a "car" I think that somebody got at least 200 mpg with that I was watching on tv. Of course this "car" was really just a seat on wheels and it was run around a track at low speed. Really just a science experiment to see how little gas per mile driven one could get. Current hybrids will need to be 4X as efficient to get 200 mpg.

Absolute BULL. RX-7s are extremely reliable. The RX-2s - early 1970s were UNreliable because of the seals. By the RX4, they were getting well over 100k miles before a rebuild . . .my RX 5 (Roger, did you get my reply on the "almost 300HP" on my RX-5s) is quite reliable and the nRX7s, more so.

Mazda simply had problems meeting "emissions" standards with the RX-7s. No problem to own one now in any state.

 

[Atlechnik]

Originally posted by: Eli

Originally posted by: FreshPrince
Ok, got done reading that article...looks like it's less efficient than conventional piston engine. Why did Mazda go with this engine?

I think you've got that backwards.

It is much more efficient than a piston engine. Read how a conventional 4-cycle auto engine works, then read about 2-cycle engines, then read the rotary articles again.

 

I give up trying to educate the masses in OT, Atlechnik, rotary engines are very fuel inefficiant, they are however very space efficiant.


Unbelievable :disgust:

 

[Atlechnik]

Originally posted by: FreshPrince
Ok, got done reading that article...looks like it's less efficient than conventional piston engine. Why did Mazda go with this engine?

First, it is lighter, more space efficient and less moving parts then a piston engine, thus less prone to brake. Secondly, looking at the history of the RX-7, the RX-8 is based off, one will notice that the rotary engine has been in the RX since the first car, its what made this car so famous in the first place. The car is just sticking to its heritage.

 

[SagaLore]

Originally posted by: Eli

Originally posted by: SagaLore

Originally posted by: Eli

Originally posted by: Eli

Originally posted by: SagaLore
Check out this new engine design:

Five Stroke

Without looking at the site, it is the "extended combustion" design you spoke of, correct?

Hmm.. Not sure if it was what you were referring to or not.

That is definately an interesting design for a diesel engine. Wonder if we'll ever see anything come from them, or something similar...

It seems hard to find any inherent flaws, because it is just an extensive modification of current diesels. Of course, the questions would be.. how reliable is the so called "combustion shaft".. it seems it would be taking a great deal of abuse..

Interesting though.

I would guess less abuse than a typical cylinder, because there are no moving parts inside it, so no extra friction. Since it's a solid cylindrical mass, it should be sturdy enough for that kind of internal pressure, not sure about heat buildup though.

Well, the "combustion shaft" rotates, so there's friction somewhere.. the ports on the combustion shaft have to match up with the ports above the pistons, so there's going to be friction there..

That's kinda what I meant. It kinda sucks that any drastic engine design change probably isn't going to be embraced too well, unless it is truely revolutionary. We've managed to get our engines pretty damn reliable.

Adding more moving parts almost seems like a step in the wrong direction. I think at this point, we need better materials.

But if adding the moving parts takes the place of several other moving parts with less energy waste, then you've got a winner. That shaft cycliner could have rounded ports so they never have to line up exactly and it could be on a ball bearing mechanism to really reduce friction.

What you need is a carbon-carbon composite. Which is an existing technology. And a newer technology is diamond glossing - you can cover a surface in smooth diamond. Extremely high thermal abilities with no need for lubrication.

 

[WinkOsmosis]

Originally posted by: Roger
I give up trying to educate the masses in OT, Atlechnik, rotary engines are very fuel inefficiant, they are however very space efficiant.


Unbelievable :disgust:

Hey, I knew that rotaries are inefficient. All you have to do is look at the design to figure that out. In a piston engine, the burning fuel drives the pistons downward. In a rotary, burning fuel drives the triangle inward and also has to slide it at a funny angle, and there isn't much room for expansion.

 

[WinkOsmosis]

Originally posted by: SagaLore

Originally posted by: Eli

Originally posted by: SagaLore

Originally posted by: Eli

Originally posted by: Eli

Originally posted by: SagaLore
Check out this new engine design:

Five Stroke

Without looking at the site, it is the "extended combustion" design you spoke of, correct?

Hmm.. Not sure if it was what you were referring to or not.

That is definately an interesting design for a diesel engine. Wonder if we'll ever see anything come from them, or something similar...

It seems hard to find any inherent flaws, because it is just an extensive modification of current diesels. Of course, the questions would be.. how reliable is the so called "combustion shaft".. it seems it would be taking a great deal of abuse..

Interesting though.

I would guess less abuse than a typical cylinder, because there are no moving parts inside it, so no extra friction. Since it's a solid cylindrical mass, it should be sturdy enough for that kind of internal pressure, not sure about heat buildup though.

Well, the "combustion shaft" rotates, so there's friction somewhere.. the ports on the combustion shaft have to match up with the ports above the pistons, so there's going to be friction there..

That's kinda what I meant. It kinda sucks that any drastic engine design change probably isn't going to be embraced too well, unless it is truely revolutionary. We've managed to get our engines pretty damn reliable.

Adding more moving parts almost seems like a step in the wrong direction. I think at this point, we need better materials.

But if adding the moving parts takes the place of several other moving parts with less energy waste, then you've got a winner. That shaft cycliner could have rounded ports so they never have to line up exactly and it could be on a ball bearing mechanism to really reduce friction.

What you need is a carbon-carbon composite. Which is an existing technology. And a newer technology is diamond glossing - you can cover a surface in smooth diamond. Extremely high thermal abilities with no need for lubrication.

Diamond is a 3d crystalline matrix. You can't coat a 3d surface with it. That stuff is graphite.

 

[apoppin]

Originally posted by: Roger
I give up trying to educate the masses in OT, Atlechnik, rotary engines are very fuel inefficiant, they are however very space efficiant.


Unbelievable :disgust:

It's believable . . . on OT.

I'd say 280 hp (plus) from a carburetted 1.3 L engine is "space-efficient" as well as powerful for it's size.

And my RX-5 regularly got 20 MPG under the hardest driving conditions . . . not bad for a Japanese "muscle car".

 

[SagaLore]

Originally posted by: WinkOsmosis

Originally posted by: SagaLore

Originally posted by: Eli

Originally posted by: SagaLore

Originally posted by: Eli

Originally posted by: Eli

Originally posted by: SagaLore
Check out this new engine design:

Five Stroke

Without looking at the site, it is the "extended combustion" design you spoke of, correct?

Hmm.. Not sure if it was what you were referring to or not.

That is definately an interesting design for a diesel engine. Wonder if we'll ever see anything come from them, or something similar...

It seems hard to find any inherent flaws, because it is just an extensive modification of current diesels. Of course, the questions would be.. how reliable is the so called "combustion shaft".. it seems it would be taking a great deal of abuse..

Interesting though.

I would guess less abuse than a typical cylinder, because there are no moving parts inside it, so no extra friction. Since it's a solid cylindrical mass, it should be sturdy enough for that kind of internal pressure, not sure about heat buildup though.

Well, the "combustion shaft" rotates, so there's friction somewhere.. the ports on the combustion shaft have to match up with the ports above the pistons, so there's going to be friction there..

That's kinda what I meant. It kinda sucks that any drastic engine design change probably isn't going to be embraced too well, unless it is truely revolutionary. We've managed to get our engines pretty damn reliable.

Adding more moving parts almost seems like a step in the wrong direction. I think at this point, we need better materials.

But if adding the moving parts takes the place of several other moving parts with less energy waste, then you've got a winner. That shaft cycliner could have rounded ports so they never have to line up exactly and it could be on a ball bearing mechanism to really reduce friction.

What you need is a carbon-carbon composite. Which is an existing technology. And a newer technology is diamond glossing - you can cover a surface in smooth diamond. Extremely high thermal abilities with no need for lubrication.

Diamond is a 3d crystalline matrix. You can't coat a 3d surface with it. That stuff is graphite.

Composite Diamond Coating

Diamond Film

 

[WinkOsmosis]

Originally posted by: SagaLore

Originally posted by: WinkOsmosis

Originally posted by: SagaLore

Originally posted by: Eli

Originally posted by: SagaLore

Originally posted by: Eli

Originally posted by: Eli

Originally posted by: SagaLore
Check out this new engine design:

Five Stroke

Without looking at the site, it is the "extended combustion" design you spoke of, correct?

Hmm.. Not sure if it was what you were referring to or not.

That is definately an interesting design for a diesel engine. Wonder if we'll ever see anything come from them, or something similar...

It seems hard to find any inherent flaws, because it is just an extensive modification of current diesels. Of course, the questions would be.. how reliable is the so called "combustion shaft".. it seems it would be taking a great deal of abuse..

Interesting though.

I would guess less abuse than a typical cylinder, because there are no moving parts inside it, so no extra friction. Since it's a solid cylindrical mass, it should be sturdy enough for that kind of internal pressure, not sure about heat buildup though.

Well, the "combustion shaft" rotates, so there's friction somewhere.. the ports on the combustion shaft have to match up with the ports above the pistons, so there's going to be friction there..

That's kinda what I meant. It kinda sucks that any drastic engine design change probably isn't going to be embraced too well, unless it is truely revolutionary. We've managed to get our engines pretty damn reliable.

Adding more moving parts almost seems like a step in the wrong direction. I think at this point, we need better materials.

But if adding the moving parts takes the place of several other moving parts with less energy waste, then you've got a winner. That shaft cycliner could have rounded ports so they never have to line up exactly and it could be on a ball bearing mechanism to really reduce friction.

What you need is a carbon-carbon composite. Which is an existing technology. And a newer technology is diamond glossing - you can cover a surface in smooth diamond. Extremely high thermal abilities with no need for lubrication.

Diamond is a 3d crystalline matrix. You can't coat a 3d surface with it. That stuff is graphite.

Composite Diamond Coating

Diamond Film

:Q

 

[Eli]

Originally posted by: SagaLore

Originally posted by: Eli

Originally posted by: SagaLore

Originally posted by: Eli

Originally posted by: Eli

Originally posted by: SagaLore
Check out this new engine design:

Five Stroke

Without looking at the site, it is the "extended combustion" design you spoke of, correct?

Hmm.. Not sure if it was what you were referring to or not.

That is definately an interesting design for a diesel engine. Wonder if we'll ever see anything come from them, or something similar...

It seems hard to find any inherent flaws, because it is just an extensive modification of current diesels. Of course, the questions would be.. how reliable is the so called "combustion shaft".. it seems it would be taking a great deal of abuse..

Interesting though.

I would guess less abuse than a typical cylinder, because there are no moving parts inside it, so no extra friction. Since it's a solid cylindrical mass, it should be sturdy enough for that kind of internal pressure, not sure about heat buildup though.

Well, the "combustion shaft" rotates, so there's friction somewhere.. the ports on the combustion shaft have to match up with the ports above the pistons, so there's going to be friction there..

That's kinda what I meant. It kinda sucks that any drastic engine design change probably isn't going to be embraced too well, unless it is truely revolutionary. We've managed to get our engines pretty damn reliable.

Adding more moving parts almost seems like a step in the wrong direction. I think at this point, we need better materials.

But if adding the moving parts takes the place of several other moving parts with less energy waste, then you've got a winner. That shaft cycliner could have rounded ports so they never have to line up exactly and it could be on a ball bearing mechanism to really reduce friction.

What you need is a carbon-carbon composite. Which is an existing technology. And a newer technology is diamond glossing - you can cover a surface in smooth diamond. Extremely high thermal abilities with no need for lubrication.

Interesting, although I would tend to disagree on the lubrication aspect.. it would still eventually wear, and any reduction in friction is a good thing. Just because may technically not need lubrication doesen't mean we wouldn't use it.