wrongfullyaccuzd

OK so i finally took it upon myself to go to the mazda website to try to understand how the legendary rotary engine works in the rx-8. i think i have it down, more or less, but i'd like to hear thoughts from more experienced, more knowledgeable people...rotary or combustion? preference? why? what does one have that the other doesn't? which is better for performance, reliability, etc.? anything major comparisons you can think of.

magnum

I think you mean rotary vs. piston.

www.howstuffworks.com search for rotary engine.

Read that article until you get it. There are different rotary engines just like how there are different piston engines so it's kind of hard to compare. Mostly the 12A (carbeurated 2 rotor used in the first generation RX7), 13B (naturally aspirated, EFI, 2 rotor found in the second generation rx7 1986-1991), 13B-T (turbo 2 rotor with efi found on the second gen rx7 turbo2 model), the 13B-REW found on the third gen rx7 (twin turbo 2 rotor with EFI), and the 20B which is off the Mazda Cosmo (3 rotor, twin turbo, EFI...costs about $10,000 to $20,000 to swap into a second or third generation rx7.)

It's as hard to generalize all rotory engines as it is to generalize all piston engines. It's just a design. The rotary engine is still in it's infancy compared to the piston engine thus requiring more maintenance and still not as reliable as most 4 cyl engines. Anyways, read up and come back with any questions...I'll try to help the best I can.

Moonduck

I've got a friend that is a rotary nut, says they're way easier to work on, cheaper, better performance for the mpg, etc. He has shown that with competent help (a rotary nut like himself), he can perform a basic engine swap in a first gen in less than an hour. They're also supposed to be great for real tuners as you can do all sorts of stuff to those engines by hand if you know what you're doing.

I personally think it's a neat design. If I ever see one dead cheap, I'l likely pick it up just to see if they're as sweet as he makes 'em out to be. Until, then, they're a neat idea.

numist

explain to me exactly what the difference is between rotary and piston...

I dont understand the basic design, and havent been able to find anything that explains it sufficiently

billege

http://travel.howstuffworks.com/rotary-engine.htm


That will explain, in much more detail, then I'd EVER type in here.

I hope it helps.

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ziadel

basically, you have an offcenter triangle thing that never stops turning in the same direction (theres a lot more to it, but I am somehwat sure that the reason they say its so better is because of that)
a piston engine has pistons that get pushed down, then they change direction and come back up, a power loss...



as far as I am concened, my absolutely incredibly biased and somewhat uneducated opinion is that the wanker er, I mean wankel engines are complete crap and really shouldnt be given a second look...

my buddy in england was gonna get an RX-7, but according to him, no matter what he did to it, no matter how much he baby'd it, it would still grenade at 60k miles... I've heard others refute that quite loudly, but I trust him.





heres a rule of thumb I live by:If it doesnt have 8 cylinders, a carburetor and pushrods, its crap!



p.s. changing out an engine in an hour doesnt impress me, tell your friend to post up himself when he can swap out a first gen mustang engine in half that time

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Peryn

I dont want to be too rude, but Ziadel, you have no idea what you are talking about. Your freind doesn't seem too informed either...or he doesn't know how to take care of his car.

As for the how a rotary works, howstuffworks is an awesome site. Anyway, as a kid did you ever play with Spirograph or something like that? It had various gear looking things you put in each other, spun your pin around and it make a cool design. It works just like one of those. As the triangle spins, it end up spinning a gear in the middle. This is the equivelent of your Crankshaft.


Anyway, while it hasn't had near the R&D that a piston engine has, i think it is a far superior design. It uses essentially 3 moving parts (2 rotors, and an eccentric shaft). Whereas a piston engine uses hundreds (pistons, connecting rods, cranks, cams, distrib, valves, springs, etc..). This means there is far less that can break or go bad, making it pretty cheap to fix back up. Also to me it makes more sense from a logical standpoint. If you want to spin a rod (turn the crank) ... doesn't it make more sense to spin the rod directly, than make a bunch of pistions move up and down, and then convert that to a spinning motion? It just seems easier and a better idea to make your combustion directly spin a shaft than have to conver reciprocating motion to a twisting motion.

Yet another advantage is weight. A rotary produces for more power for its weight and size than probably any other motor on the planet. (well, for the most part). Even if you do have to worry about CA emissions (pretty much the harest emissions to pass), you can make the power of a v6 or some v8's out of an engine the size of a small 4 cyl, maybe even a large 3 cyl. If emissions aren't an issue, the rotary is by far the best way to make monster power out of a small powerhouse. TT setups like the 13b-REW can make 500 horses without too much problem. And with the piping its still pretty much the size/weight of a typical 4 banger.

Another advantage is the shape of the engine. Because you spin the shaft directly, in a circular motion, the weight of the engine is in a fairly small circle around the shaft. This means it doesn't have cams, cylinderwalls, valve covers, etc. to make the weight of the engine much higher than teh crankshaft. So it sits down much lower in the car and, combine with its short length, makes for a much lower, shorter, lighter position of the engine, dramatically helping the Center of Gravity of the car its in. Hence the reason the RX-7's handle so unbelievably well.


There are a few disadvantaged though with it. These can be a kinda big deal if you know nothing about cars and are in no way mechanically inclined.

Oil : due to the nature of the engine, they burn a little oil in teh combustion chamber. Because of this, you need to be very good with your maintenance, and keep oil in it. Also, you need to keep an eye on how fast your burning it, to make sure nothing else is wrong. You also must change your oil regularly. Cant really afford too much to wait an extra 1-2k between changes, or you will shorten your engine life. Also, you hafta get used to seeing smoke out the tailpipes when you start it up...sometimes a LOT of smoke.

Mechanical Knowledge : It helps a lot if you work on your own car. Not many people know how a rotary works, let alone are qualified to touch or even work on them. It is hard to find a good mechanic to work on your car that wont make the situation worse, and when you do, be prepared to pay for it. Parts aren't too bad (though mazda parts are ALWAYS more expensive than other manuf.'s), but you will pay big time for his labor.

Reliability : They tend to be very reliable engines if you take car of them. Well, for the first 100-120k they are. Then chances are you will need to take out the engine and replace some of the seals internally. The apex seal doesn't last too long. Someone was saying his cars wouldn't last more than 60k miles, that about 1/2 what it normally lasts. Either he wasn't taking very good care of his cars, or he was getting cars that were neglected. Its really not too bad to rebuild the engine and its seals (and as long as your at it, do some porting to get more power out of it) but most people find it a large anoyance, and thus label the engines as a POS.

Overheating : The rotary has some aluminum housings. As such, you CANNOT let it overheat. They actually have a very capable cooling system, and this will probably never be an issue unlesss your radiator blows, but engine death can occur if you drive it while its overheating. Another reason most common people think its a bad engine, is they hafta be so careful about that. Of course its really not much different than other aluminum engines. They will have very bad problems as well if you let them overheat.


There is probably more im missing, or some facts i might have messed up. I just got up, so who knows what i wrote... im a zombie right now. What it basically comes down to is i like a rotary very much. They are also pretty reliable if you are willing to throw some rutine maintenece at your car, and learn what it needs to be taken care of.


Oh another thing, rotaries then to be not as clean as piston engines these days. They also dont get great gas mileage. On a more positive note, they respond much better to basic airflow increases than almost any piston engine will....even the turbo ones. People claim to get upwards of 10-15 HP with a very good intake, headers, and exhaust system on a piston car. you could probably realistically get 20-25 off of a good intake/exhaust system with a rotary. Also, rotaries dont make any low end torque unless you get into a 3 or 4 rotor. They also rev very high, and very fast.

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clonmult

Peryn - you missed one thing ... they are also very smooth (apparently).

The reliability - I'll check with one of the guys here, he commutes probably 100+ miles a day in a tuned RX-7, big bore exhaust, black body/windows ... god, it looks good. But I'm sure he wouldn't do that sort of distance every day in lousy traffic in a car that wasn't reliable.

WarWagon

My 83 with the 12a is indeed very reliable, but I also do all the work on my own cars religiously. They rev quicker and smoother than most motors you encounter, but they're NOT great on gas mileage. Peryn is very correct in that they do burn oil naturally (it is suggested that you do NOT run synthetic oil in them, at least not the older ones) and the apex seals are usually the first things to go, and often upgraded to the later style ones during rebuilds.

To compensate for the lack of bottom end, they were geared very low from the factory and were very lightweight (3.90 gear and I believe about 2600 lbs.) They do indeed respond very well, particularly to exhaust upgrades. Porting the motors is also a relatively simple ordeal, and is a much less complex ordeal than a piston based motor with intake/exhaust valves.

Peryn

Yeah, i forgot about how smooth they are. Its something crazy to stomp on the pedal in one of those. Incredibly smooth and they rev very fast. My bro had his apart and we gasket matched the ports, did a throttle body mod to stop the bouncing idle (amongst other things) and opened up the air filter housing to allow air to get in faster. That thing revs to 6grand before i could hit 2k in my jeep. Also, rotaries have a very unique sound. They sound like a turbine at some points, like a weedwacker on ateroids at others. As for reliability, cant remember what i wrote, but if you do the maintenance and keep them in good working order, my experience is that they are very reliable and can last quite some time before needing new apex seals if taken care of well.

Something else very cool about them is if you open up the airflow just a little, they make a very cool *POP* when shifting at high RPMs. It get louder and more cool sounding as you increase airflow even more too. Also, its not too difficult to make them spit flames either. A good intake kit, a little porting and nice open exhaust = cool pop, plus the ability to spew a little flame out the back. Well, i've heard that about the flames, but only seen it once.

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BooRadley

Better performance for the MPG? Rotaries have notoriously low MPG because they have a low compression ratio. Do not try to argue unless you have had more engineering thermodynamics than myself (I'm about a year from graduating with a Mechanical Engineering degree. I am not joking. I have been told several times how "engines work" by people who haven't the faintest clue of anything related to actual science, and don't want to hear it anymore.


Sigh. I apologize for ranting.

Pragma

Just as an aside, could we get a moderator to fix the title of the thread? I twitch every time I see "rotary vs. combusion".

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Moonduck

Okay, I shouldn't argue with you because of your incipient engineering degree? Interesting style of argument. How about you shouldn't argue with me because I have brown hair? Or maybe you shouldn't argue with me because my screen name starts with an "M". Shitty argument technique, weak as hell, and irrelevent. I can tell you all sorts of BS qualifications I have and they won't mean a jot more than what you offered simply because you failed to back up what you say.

The statement I offered was 1) anecdotal, as I said it was coming from a friend what is a rotary nut, and 2) comparing performance/MPG, not discussing MPG. Your "notoriously poor MPG" comment is about as relevant as your upcoming degree. I made zero comments about what sort of MPG rotaries get. I made a comment about what performance they can squeeze from the gas they eat. From what experience I have in his RX-7, it's pretty damned good. It beat my Z on both performance and MPG (not too hard, my Z was NA and an automatic).

Two pieces of advice.

A) Finish your degree. It don't mean a thing until you're done with it and using it.
B) Don't ever tell anyone not to argue with for an insipid reason like you having a degree in mechanical engineering. You could be talking to Soichira Honda for all you know and he'd could shove it down your throat.

Peryn

Your getting pretty defensive...for a somewhat logical reason.....but your wrong. MPG and anything associated with it is definately one of the downsides of a rotary. For any amount of gas you use, There are many many MANY engines that will out perform it on the same amount of gas.

Example : in 1995, the RX-7 got the same city mileage, and worse highway mileage than a Chevrolet Corvette. The corvette made 50 more horsepower. The Mazda clearly had inferior performance/MPG than Chevy. On the same note, in 1989 the '89Corvette made 80 more horsepower than the '89 rx-7 and has similar and better gas mileage. In 2003, the ZO6 makes 150HP MORE than the '95 rx-7 (which i believe had the best performance/MPG of the rx-7's history) and the corvette has the same city mileage and better highway mileage.

The list of cars could go on and on, but rotaries simply do not get much power for their gas usage compared to most piston engines. Maybe you misunderstood your freind, or maybe your freind was wrong....or did something freakish and unheard of to decrease his gas usage. Either way, you are wrong, whether that guy has a degree in whatever or not.


As for the title of this thread, the Wankel is still an internal combustion engine. Its just not a reciprocating engine. It would be nice if someone would fix the title to say "Rotary vs. Pistons" or something similar.

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Moonduck

This I can easily accept. As I said, it was anecdotal evidence, not extensive personal experience. You gave actual examples that I can accept. The only nits I would pick is to wonder about relative engine weight (as it affects performance) and such intangibles as throttle response. (In other words, weak arguments as I am not a Wankel nut)

The important thing is that I am not arguing the triumphant superiority of the Wankel. I said that I think it is a neat design, still do. I find it impressive that the car that you chose to compare it to was a Vette, arguable one of the most R&D heavy NA street cars around. GM probably put as much money simply into tuning the Vette as Mazda did on the entire design and build of their rotary. Given the massive proliferation of the V8, the staggering number of people constantly working to push the envelope on the V8, and the stupefying amount of money thrown into R&D on piston engines in general, of course it is going to have the edge. The fact that only one company uses a rotary tells its' own tale.

In conclusion, I'm not saying that it is better, just different, and given the limitations I mentioned above, it does a damned good job of holding its' own.

Oh, and I could just as easily come up with a bunch of engines that have inferior performance and MPG, so don't think I'm rolling over because of one measly example =)

BooRadley

Well, I am using it, but I guess the fact that I'm interviewing with Toyota and several Tier 1 automotive company suppliers isn't using my degree, as I currently haven't accepted a job yet.
The amount of ricers that are 16 year old kids on any automotive board is obnoxious, and I've heard every nonsensical argument in the book and am frankly tired of arguing every point into the ground for the sake of spreading correct information. So , I throw out my "BS" qualifications to give myself more inital credibility. As for you Sochiro Honda comment, I've had to listen to plenty of people tell me in real life about cars and have felt like Sochiro Honda in that case. Sorry if I got a little quick with you, but I can't screen out the ricers, and for every knowledagble person there is on the internet, there are 100 bullshiters. Please accept my apology and lets not get into a flamewar.

And , to prove that I don't have a bunch of BS qualifications, I'll attempt to prove my point.

First of all, we need to choose how we define "rotary MPG". Lets generalize it to engine only and compare it to a similar displacement, naturally aspirated internal combustion engine. The weight will be approximately the same either way, and the RX7 was a very aerodynamic and lightweight car, so the chassis got better efficency than most other cars.

The rotary engine is a normal spark-combustion engine. It has a different configuration than the normal piston engine, but it still is a 4-cycle spark ignition engine. Classic thermodynamics states that a 4-cycle engine gains maximum theoretical efficency at the following conditions: (assuming everything else, including internal friction, remains constant and the only variable is compression ratio) :
Efficency goes up as compression ratio goes up.

The graph is roughly linear with the % efficency ( total work out, from combustion/ amount of work put into system, thereotical maximum )

Now, the classic( Pre RX-8) rotary engines had a very low compression ratio simply from the apex seal not being able to seal completely on the strokes ... a compression ratio figure around 6.5:1. In order to counteract this, engineers added turbos to boost the efficency of the engine and bump the compression ratio up to an effective 9.5:1 in stock form (with a perfect seal, it would be much higher but some of the compressed air is just going to go straight past the seal and into the exhaust, a characteristic sound of RX7s) , but in doing so , turbos take power away from the engine to compress air. If you compared a naturally aspirated engine of the exact same compression ratio, the Turbo Rotary would be burning more fuel but producing more horsepower at the same time because of the added effect of the turbos. The internal friction is slightly less in a rotary, but the lower initial compression ratio makes the overall efficency less because of the required turbos. Without turbos, the old generation rotary would be inefficent and not a good performer. On these old cars, the seal didn't age gracefully and became gradually worse over the years , making a relatively short engine life.

Now, the new rotaries... the RX8... supossedly has been extensively reengineered for optimum performancel ( I haven't looked much into it) and should have alot better economy and power because it holds its compression ratio better and doesn't require turbos (which do take power, despite what anyone says, how else are you going to compress air?).

Moon, I hope this illustrates my point. My sources are the Bosch Automotive handbook and Fundamentals of Engineering Thermodynamics by Moran and Shapiro. Feel free to ask any questions.

Peryn

Ummm....thats mostly true. Except for the part about compression ratios. Rotaries tend to be a little lower, but they are still pretty much on par with a piston engine. The 13b (not the one out of the twin turbo last gen ones) has a CR of 9.7 on the N/A ones, and 9.0 on the TurboII. The third gen 93-95 engines had a CR of 9.0 :1 as well. The first gen 12A motor had a 9.4 : 1 compression ratio.

I beg to differ. The N/A motors weren't as efficient in terms of Power/Gas as the turbo motors, but they were by no means "inefficient". And certainly not bad performers. 160HP isn't great, but how many cars back then had an NA motor capable of producing that much power out of that small of a motor? Prety much nobody that i know of.



Oh, and BTW, the RX-7 certainly didn't require turbos ("because it holds its compression ratio better and doesn't require turbos "). It had plenty of zip without them.

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BooRadley

My information was slightly flawed. I had read ( don't trust the internet, kids that the CR was with boost factored in ( as obviously boost increases CR ). If it can run on pump gas, then that seemed like a reasonable number to me with boost factored in. I doubt you could maintain an effective ratio of 15:1 without race gas or water injection... but then again, I don't know everything. Some people run 24 psi with 93 octane in their Eclipses, so I'm not the turbo master,and I'll be the first to admit that.

I still maintain the seals are far from perfect ( Aforementioned track record of failing seals and rebuilds every 80-90k miles ) and that 9.7 CR wouldn't hold for long and things would get worse... some people swear 150k, some people swear 200k, but I think many of these owners bought a car that has had an engine rebuilt once.... I have 4 friends whom have owned RX7s of varying generations, and all are pretty adamant about the 80k limit with the exception of new cars that have been religiously maintained and not ragged out.

Don't get me wrong. I'm not hating on the rotaries in anyway . I think they are great.
But their added horsepower adds increased fuel consumption. If you have a 1.3L rotary, you will consume alot more fuel than a 1.3L NA street engine unless it has a race build on it....

I found a cool article on Dragsport.com, http://www.dragsport.com/dept/tech/2/ comparing rotaries to pistons, definitely worth a check. It outlines compression ratios like I have and their effects on performance.

Something I have failed to point out that this article illustrates is the fact that the rotary has a power stroke every 270 degrees... instead of every 720 degrees for regular reciprocating engines. This is definitely a reason why rotaries produce much more power. Read the article for more info.

Moonduck

Understood, sir, and I also was quick to get snarky as well.

As an aside, I'm no ricer. The Z I owned was a beat NA/AT/POS that I drove simply because I picked it up dirt cheap. I puttered around in it for about 3 months (doing repairs the whole time) and happily sold it when offered twice what I paid for it (still a good deal for the guy what bought it). I've owned far more "muscle" cars than sporty cars, and most of them have been varying shades of primer, as all the money went into engine, trans, and suspension work.

The only rice I like is steamed or fried, usually with soysauce in either format. Also, I will be wearing a shirt with "Toyota" on it myself, come next week at my new job (Yay me!)



Well, I think it would be entirely unfair to compare it on a performance/displacment. They more or less own that curve =) I do think it valid to compare similar sizes though. A large displacement engine with large bore size is not a terribly valid comparison. Something small and high-winding is closer.



*snip discussion of compression*
Valid points, Boo. Not being a Wankel guy, I can't really argue those numbers directly except to say that they sound a bit on the low side. I could easily see a ragged out engine putting forth low numbers like that, but I doubt they'd ever pass any sort of real emissions tests with the sort of inefficient sombustion that such low numbers would produce. Admittedly, emissions is a major weak point for the Wankels, so perhaps you are closer to correct than I see at first glance.

Absolutely, though I think that the compression issue was covered in later posts than this. Like I said, I'm not waving the flag for Mazda, just making comment. I think you've outlined your point well, and I've made as much of a point as I am willing to make seeing as how I don't really have a dog in this fight.

nightshade000

In my experiences, wankel engines really kick ass. The mazda 1.3lt engines put out a hell of a lot of horsepower for such a small engine. However, the brighter the candle burns, the faster it burns out.. Mazda's rotories DO eat apex seals, and oil (the oil bit is by design). You really have to give them a lot of TLC to keep them running, but boy can they run. One major weakness of mazda's rotory engines is low torque, but I think that's largely due to the lack of displacement.

Not intrisctic to wankel engines specificaly, but the mazda rx7's also had 50/50 weight distribution, combined with a strong engine and rear wheel drive makes it a really strong contender.

Peryn

They definately do NOT make low end torque. Though i have heard that the 20b (3 rotor) actually does a pretty good job of it...at least much moreso than their 2 rotor counterparts. Never driven one, but it must be wierd driving a rotary with a nice high redline AND have low end torque. If this is true....i wonder where the 4 rotor made its power....

But apex seals....yeah, they do go. Most of my experience shows 100-120k more frequently than 80k, but i guess it also depends on the location. In SoCal, we're not going to have near as many cold winter morning starts, extreme weather conditions or whatnot like you will with other parts of the country. Luckily though, its a fairly cheap/easy rebuild to fix up the engine again. Not too expensive to just get a new one either.

Anyway, its nice to have a piston engine if you want a low end torque monster, but if i were ever to get a light car with a high revving engine, rotary would absolutely be the way i would go. They are a blast and a half to drive. For those who never have, i highly recommend going out and test driving the rx-8.

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bad30th

Dont get me wrong, I do like the design of the rotary and its simplicity, but....

Its been my experience that with a rotary, there are a series of trade-offs.

A NA rotary has relatively low torque numbers (low-end and peak).... with somewhat decent reliability (being NA, there is much less of a strain on the apex seals).

Add a turbo, and the torque problem is somewhat improved, but you throw your reliability right out the window. I say this because, yes an extremely well tuned and maintained turbo rotary can last, but most are not so well tuned or maintained..... In other words, chances are, you WILL blow your apex seals in your turbo rotary.

And as far as gas mileage goes, its already been said that rotaries have a lower compression ratio, which = less performance per gallon. And if its a turbo rotary, well you can just forget it.....talk to anyone with a turbo and they will tell you that if they are driving for gas mileage, they do everything in their power NOT to boost, because Boost = Guzzling Gas

telekinetic2

20b's are the V8 of rotaries...low end torque, nice HP when forced induction is applied...check out this video of an FC at the dragstrip with a 20b with a blower.

http://jackson57.customer.netspace.n...%20alright.WMV

:-)

Moonduck

Now that's what I call putting ona show for the folks in the stands.

I did like the noise it made revving high. Blower plus normal rotary just sounds cool.

numist

thanks for the link to howstuffworks... thats an awesome source

very enlightened now, seems like a great concept, but very limited in compression, still could be refined though with internal modifications, it would just be very difficult

madsenj37

One thing to note about howstuffworks.com. Their illustration on the rotary is only valid for pre rx-8 designs. Due to the new design of the rotary, the new placement of the exhaust ports I believe, the illustration is somewhat off.

Now on to the gas mileage concern of a rotary. It is designed solely for performance. Show me a 1.3L 4 cyclinder that has 238 hp and I will show you a 'gas guzzler' as well.

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perth1

my second car was a series 1 rx7, 1978. i loved that thing.... weber carb, 13B J-port, supra gearbox, 4.4:1 locked diff. looked like a piece of absolute shite, but it did a 13.1 second pass at a ravenswood street meet! not a bad pass for a natural aspirated rotary

hahaha

I think it's cool that they're different than piston engines, and I like the simplicity, but Ive heard some stories. Apparently you have to take off the exhaust manifold to take out one of the spark plugs. Give it some time and it should be awesome.

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Peryn

You dont hafta take off any manifold to get the spark plugs out, at least not on the 13b. But there are 4 of em and they cost a butt load since they are a special design. Also the rx-8 moved some exhaust and intake ports around, got a better performaning, better mileage engine out of it.

As for that 1978 RX ... did you do an engine swap? 'cause the 13b wasn't in an RX-7 in the states till 84 or 85 in the GSL-SE.

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pocon1

My spark plugs for my 87 rx7 run about 6 bucks a plug. Not too bad. Also, my other two cars use synthetic, but mazda recommends dino oil because of the way oil is specifically consumed on the combustion chamber, so I save money there.

Tiser

Even though Mazda always quotes their engines as a 1.3L, there are always two combustion regions performing duty at the same time. Whenever a rotary competes it is always classified as 2x the displacement. That 1.3L figure is really just Mazda marketing - it's really a 2.6L.

potato

I have read that it usualy costs more to repair

bad30th

I second that...rotaries are exactly double their advertised displacement. Is a marketing scam

madsenj37

As per my understanding of the issue, it is not that simple to just say since each rotor has its own displacement that the displacement is twice as much. The rotors arent necessarily on the same cycle at the same time, meaning its not burning 1.3L x 2 at the same time. It might be burning in one and exhausting in the other at the same time, but technically thats not burning 2.6 L at the same time.

Also Mazda would not be able to sell the car as 1.3L if it really was 2.6L. Thats false advertising and its against the law.

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perth1

Yep, saved all my pennies to mod that car, new engine, new gearbox, new diff, new axles all in a piece of shite 78 rx.. hehe

SiphonX

Rotary has a fabulous design, but the tried and true piston-based engine still reigns supreme. Once rotary is pefected, it will take my vote. Simply put, Piston based is a solid block, whereas rotary is put together from many components, resulting in leaks and potential engine trouble down the line. I really like the concept behind it though, if they could somehow mix the best features from both and create some kind of super engine, that would be awesome.

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space-n-'cord

The RX-8 has come a long way towards solving most of the old Mazda rotary problems, but in order to maintain a clean engine, they have had to make huge power sacrifices. The cool thing about a rotary is that it can almost make unlimited power, but once it blows up, because of the complex parts, they are almost impossible to repair without having to spend way too much money.

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basmoq

I almost bought an 87 RX7 with only 30K on it in showroom condition for $1,500. Then I did a reality check when I saw the cost of insurance for someone 18years old with a rotary engine, and promptly bought a Saturn, hehe

geeza

Another outstanding thread on the TF motors board.

Good on you, fellas.