ever thought going to piston?
 

since the parts are cheaper, and a block will last alot longer then a rotary block would.

um.. a lot of people have. you cant take the heart out of the beast tho.. if you want piston engine i say get a car meant to have pistons.. dont ruin another rx7. not that you are..it just upsets me deep down haha

that topic is tottally ment for a different board.

but positves are

same gas milage with a v8
twice the power
cheaper parts


negatives
they wear out more..
no one will be supprised when you beat them with a v8.... everyone will when you say it has no pistons and is a 1.3L
rotarys sound nicer
and there not as cramped

wear out more? where are you guys reading this into it? i have seen a number of 250k rotaries still on the road. yes you probably should reseal them at 150k but if you are mechanically knowledgable on a rotary you can do the whole job for less than $500 and go for another 200k miles on the original parts less maybe the apex seals.

now if you use cermet housings and ceramic seals well then you probably could get upward of 400-500k out of an engine.

the bearings wont last 500k, and how do u know those 250k rotaries have been rebiult before.

^ why would someone lie about their rotary going over 200k?... i hope this thread and your post was a joke.

i hope to get 1 year of my current rebuilt, n/a motor

I think about an LS1 swap sometimes. I'm just too poor to perform the swap :( And I love the rotary too much :)
They sound beastly though.

But don't worry though, if I were ever to do an LS1 swap it would firstly be into a 240Z.

how many rotary engines have you had apart?

i can't count how many OEM engines i have split open but only after customer negligence, many motors including my daily beater have close to 200k without having been cracked open yet. the bearings are usually barely broken in on the n/a engines even after 100k miles.

the apex seals and rotor housings are the main wear points. currently i am finding many of the old oil seals are failing with age though, 20 years is a good while for a rubber seal to hold up to 300F+ daily.

You need to learn how to rebuild better then.

^^ LOL..... Agreed. The whole design and one of the many great things about a rotary is that you have a total of 3 moving parts. Less chance for failure. You can reach higher RPMs with lower stress to the engine. So I don't see why it is so suprising to see one last 200 k + If one has been babied since it was brand new I could see it lasting much longer. If you put any car rotary or piston on a service scheduel like people do with your high end cars like Mercedes, BMW, Volvo, ect any car can last forever. Fact is there is more to just changing your oil and filters every 3000 miles.

Dumbest lie in the history of the automobile.

If there are only 3 moving parts, where are the apex seals and springs, sitting in the glove box? It's like saying valvesprings don't move in a pushrod motor because they only compress and expand, they don't actually turn. Last time I checked, a number of things in a rotary engine moved. Including several that FREQUENTLY CAUSE ROTARY ENGINES TO FAIL.

In boosted applications, yes. N/A rotaries will run forever with their 3 moving parts :).

My biggest gripe is that anything a rotary does is only relevant becaues its a rotary that did it.

I really dont CARE about that. I want performance the way I want it without any idiosyncratsies or the fact that under boost its gonna only last 50K miles on average. "beating with a rotary" or "with a '1.3' liter" doesnt matter, being SPECIAL doesnt matter, and emotional/subjective arguements that sound more like someone in a doo-rag talking a bout his gang/culture/mama really dont matter either.

Its a GREAT chassis that you can basically do whatEVER the hell you want to do with it and excel at it, and its really a shame that no domestic comes close to it (Especially in bang/buck) except for the corvette, which has GM's LEGENDARY lack of build quality.

Honestly if I could find a vette cheap Id be playing with one, but because FCs are so cheap, and a STEAL for what you get, how could I not use one? I love the chassis's performance but I dont want a rotarys powerband or limitations - and yes, it has plenty of them. If Mazda put 20Bs in american RX7s maybe it would be different, but they didn't, so here we are.

As was asked in another thread, do you think so little of the car OUTSIDE that engine that it is no better than any Mustang or Camaro (or Corvette) at anything NEAR it's price range? Maybe those of us that have done the swap love everything about the RX7 OTHER than teh engine (and many of us, myself included still like rotary engines). The RX7, even with the V8, looks better, is lighter, is built better, looks better, has better ergonomics, looks better, has better suspension parts and brakes, looks better, and is simply a better overall package even without the rotary. Oh, and it looks better, too. ;)


BTW, besides the eccentric shaft and the rotors themselves, there is all the timing gear, distributor(s), oil pump, water pump, seal springs, etc that move in a rotary engine, too.

and 88durel, what do you mean by "and there not as cramped" (and I don't think that chainsaws strapped to your ears sounds "nicer" but that's just me. After almost a decade of playing with weedwhacker-sounding racing rotaries, it's not my favorite sound in the world)

My FD has no distributor and no moving parts in the timing gear. We're talking internal moving parts, so there goes the oil and water pump. seal springs? that's debatable. they're not large mechanical moving parts, and they are only failure points if you do something really stupid. So, we're back to three moving parts.

Moving parts don't matter, real world horsepower:fuel consumption, horespower:doller, horesepower:power delivery time lag, horsepower:initial investment, horsepower:rebuild/mile, and horsepower:fuel smell ratios doo. :)

Ok, that's the SECOND biggest lie in the history of the automobile. I had a base model 86 RX7 that was bone stock save a catback and didn't make 76k miles before it lost compression in the rear rotor. An apex seal came apart and destroyed the rotor AND housing. A LOT more than 3 moving pieces came out of that motor when I took it apart.

Anyone care to try for a third lie? :rolleyes:

^^^ So what is it that you really bring to the boards?

ahem, one phrase, wow your life sucks.

just because it happened to you, doesnt mean that it happens to all rotaries.

no sorry, i am not taking any sides, because i work on pistons all day long, and work on rotaries on my own time. both have their own advantage, and just because you blew one too many engines doesnt mean that everyone else blows them.

well, how many moving peices are in a piston engine...
i see them all day long and 6 days a week. i seen more bent valves in 80k miles pistons then i see broken apex seals. reason being? lack of maintence, interferance engines (hunduh) can someone say timing belt go bye bye?

not for nothing, there is so much r&d in the piston history, it makes our wankel engine a thing from the past. then... we get into renesis. NOW, if i remember right, the thing doesnt have perhipheral exhaust ports. what can possible happen to the apex seals... humm.... idk.

its personal preference, just because someone else thinks rotaries are superior, you dont have to try to imply that you are right and everyone else that drives a manufacture provided motor rx7 because it came that way, is wrong.

ok make it fair, rotaries have 3 MAJOR moving parts 2 rotors and a eccen. shaft,

v8 have 8 pistons, 8connecting rods, cam and crank shaft, and x amount of (x depending on motor) valves, so what? whats your point? i took out the consideration of valve springs and piston rings and push rods if used, rocker arms if used...

now what?

what is he lying about? am i lying? no. are you lying? no.

76k motor blew on you, nice, first owner? if so, i guess its just your luck.. if not... maybe someone for got to change the oil and warm up the engine..

oh well, i'd love to rock a hemi, i personally think they are great. :) hehe... but i would love to keep the car with what it came with, SO.... bottom line... WHO CARES?

forgot to mention, why are you lying? you are lying about the biggest lie in auto history because it doesnt affect anything, it cant be that big of a lie.

Just like to make a few points here...

Whether or not an engine has had the R&D behind it as a competetor is no excuse for it not performing as good. Its WHY it doesnt, it doesnt mean it somehow doesnt have to cut the mustard any less.

Oh, and the total # of moving parts doesnt matter, its cost effectiveness and reliability. Sure, NA rotaries last a long time if stock or only mildly modded, buuut...

• Their output isn't that great
• Their SPECIFIC output is pathetic
• Their MPG sucks, and run on the rich side stock
• They're not the most practical motors around becuase of the need to rev high, the gas sucking, no torque, and the obscurity of them making it hard to get parts and service for them if something DOES go down.

You tell me, what would you rather use for reliability. A 200 hp v6, or a rotary? Whats really funny is if you even the playing field, a 200 hp v6 in a FC = 14.5 second car, with gearing WAY too short for its powerband! Low hp/liter = reliability dude, and thats responsible for a lot of the NA rotary's reliability.

They can perform, but that means carbs or a standalone, porting, and a loss of reliability, especially with turbos (the seals only last so long, knocking or not) and issues such as knocking and parts replacement if something does go awry can't be ignored.

Rotaries have their niche, but a lot of their 'accomplishments' seem only relevant when you look at it as something a rotary did, not 'an engine' did

Yet another person I have to ask...what do you bring to the boards?

Lol, nice rotor pendant.

My boss and I were pondering titanium rotors the other day. Titanium is extremely tough, has a low coefficient of expansion unlike aluminum (which, by the way, has roughly double the CE of cast iron and would cause sealing to be harder than it already is inside the rotor combustion chamber), somewhat high melting point, and would make excellent marketing material for a rotary engine manufacturer. Now if only we could get three rotor NA Ti rotor rotaries from Mazda, like maybe a 20Renesis...... I'd think the tables could turn. What do u think?

I like the rotary engine and think its unique and interesting. However I'll never own another I got tired of repairing and special ordering parts . I also think theres roome for improvment of the rotary design. The reneses showed it can be improved upon. I also think that Mazda is capeable of making a better designed rotary with different porting,different materials..better balanced. But by the time thats complete and all the R&D money and it has to pass strict SMOG it may not be cost effective,thier already expensive lil buggers to rebuild. I'll stick to my V8 thank you,and if anyone here dosnt like it too bad.

The ignore feature, if you can figure out how to use it instead of just trolling.



I'm actually quite satisfied, thanks. I agree it doesn't happen to everyone. My point was simply that NA rotaries that are left untouched can still have apex seal problems that cause the motor to come apart. My personal experience proved a common statement wrong. Period.

or lets take this approach to talking about rotory motors and the transplants that seem to find thier way into the rx7's.
One. rotarys are great motors. they make lots of top end power. especially if you have the right parts and a good tuner.
Two. The motors sound great imo. The turbos you can get for the car vary so much that it is almost endless possibilities.

Now this is why lots of people decide to go with the v-8's in the rx7.
One. You have to have the right parts for the rotary and the tuner is crucial. Not everyone has money to send thier car off or to drive it all the way out to a good tuning shop or tuner. This causes a huge problem. If you do not have the right tune you will blow motors right and left so take your pic.
the thing with the v-8's is. You can buy one do some simple bolt on's and be making more horsepower and more tourqe than the rotary.

lets face it. i think we all love the rotary but thier is the fact that we do not have the right things at the right time. so we go with something we know and parts that are readily available. thanks for the time and talk away.

Actually I'm quite capable of that. You still haven't really answered the question. What kind of help are you going to bring to the boards or is that question a little to complicated? I'm not trolling. I've tried to offer my (very little) expertise on the boards when applicable. What about you?

I see a lot of potential there. I wonder how much Ti rotors would increase the cost.

If Acura can put Ti rods in the NSX engine and Boeing can put Ti heat shields on 787s, there is no reason why Ford can't put Ti rotors in the next RX7 engine.

:rolleyes: If i recall correctly the NSX sticker is around $90K, a RR jet engine for a 787 costs in excess of a million i would think. Therefore unless you want the next rx7 to be a complete flop this isnt going to happen because you are kidding yourself if you think people will pay $90k for an experiment (the x in rotary, this last comment was a joke no flame please)

well ive seen a sunfire drop a rod through the block on a car that has only 53k on it, a ford 5.0 do the same with only 90k. shit happens to engines. woo.

i love the whole "division" thing. and the blantant jackassness from people i would expect less attitude from.

i love rotaries, and honestly, i have had much worse experiences with piston engines, but thing is, i like cars. period. hell i planning on putting a 2.5 turbo dodge into the FB i got for free. but i will still love my Turbo II.

i mean i do all my own work so i dont have to pay people, but still.

ah well. i should make a twin engine car. one with rotary and pistons. then a rip in the space-time continum will open up and the world shall end.

Haha!

Open ur eyes, the Ti heatshields are on the plane, not the engine. Look at any late model Boeing below the wing behind the engine......... pure Titanium doing nothing but being hollow air chambers between the jet blast and the fuel. The engines do have Ti blades though. :D

And the NSX rules because it is too expensive for ricers.

I'm not posting in this thread to toot my horn about how many people I've helped. When I offer advice and someone says thank you for the help, I don't need to point it out in other threads. But since you insist, here's an example of a thread I helped someone in yesterday. Do I get a cookie now? :rolleyes:

in general, piston engines are gross.

Have you even taken the valve covers off of one? OMG, what the hell is all this shit~!
They are respectable powerplants and all, but wow, fucking complex. I really like the inline 6 inmy bmw, the LS- series of motors from GM and it's hard to argue with the reliability of honda's.
BUT
my friend has a honda (closed deck h22) that takes like, 20+ hours to assemble the bottom end.
me and a friend put my motor together over an hour and a couple beers. (and yes, it works /wonderfully/, go go gadget bridgeport!)

Is he taking a few 5 hour breaks? It shouldn't take near that amount of time to assemble the bottom end of a 4 banger.

Inline 6's rock. They are super efficient and reliable engines.

Back on topic. My car's v8 is due to cost. I got the car for 800.00 with a blown rear apex seal. I got the LT1 for free from a friend who put a built race motor in his camaro.

-Mike

Nevar



;)

uhm... to each their own?

i know many think that it cant be consider a factor that the r&d level of a wankel engine is less than a piston, but I think it makes a difference. oh well... i guess its just my opinion.

i think if the wankel engine has 10 years of r&d over the piston engine, then i guess they will be more efficient, but thats just me.

uhh how about a turbine engine guys?

Wankels by design have an efficiency problem that is due to their geometry itself. You cant engineer that out of a wankel anymore than you can engineer a crankshaft out of a piston engine.

You can MINIMIZE IT by tweaking the ratio of the dimensions along the e-shaft vs radial to it, cermat coatings and metallurgy, same for direct injection - but those same gains would be even better on a piston engine.

Intrinsic attributes of a design cant really be changed without using a different design alltogether. Its just the way it is.

However, in all fairness, theyre fine in racing where efficiency isnt that big of a problem, especially in certain classes, and direct injection with stratified charge would probably make a BIG difference... but DI with stratified charge on a piston engine will always beat a rotary. And there is the whole lack of a valvetrain advantage that has its advantages as well.

Basically, what Im trying to say is let a wankel be a wankel, make it the best wankel it can be, and take advantage of their pros and minize their cons - you cant make it not be a wankel! It'll never have the BMEP/BSFC efficiency of a well designed piston motor, but it has no valve springs to wear out and in some applications its more cost effective for maintainance.

Probably your best comment ever :)

good opinion.

i dont know, and dont care too much, i dont got a problem with my 13b, cept a little rough on gasmilage.

and i dont care too much about piston cars i fix them too often, w/e i am loosing my train of thought, and im starting to think that many people on this forums are so glued to the thought of "piston > rotaries" eh well. time to go drive my rx7, with a 13b n/a in it... making my miniscule power/ powerband, gas guzzling little motor... that puts a smile on my face more than any 4-6 cylinder i've driven....

8-12 cylinder ftw.

Rotaries are border-line hydrogen fuel ready, non-hybrid.

Pistons almost rely on being a gasoline/hydrogen hybrid and require extensive modifications to be able to run off of both sources.


If I am thinking clearly here, a hydrogen powered 13B would put out more HP/torque than a hydrogen powered piston engine because of not only the lack of moving parts but the motion of the ocean itself.

To me it seems like it takes less energy to spin a pair of triangles than it does to power several lifters going up and down repetitively.


EDIT: I could be wrong... it just suprised me that no one has brought up this in the thread yet.

people take these discussions too seriously. and if all you care about when comparing cars/engines are raw numbers (hp, torque, price, etc.) and "reliability" then you are not a true car enthusiast.

i think the true measure of a car is how it makes you feel driving it. if you enjoy it, that is all there is to it. of course people modify their cars in the pursuit of more enjoyment.

it's the reason people still drive slow british sports cars from the 1970s, etc...

If this were the case, it would be happening with whatever fuel you were using, such as the gasoline they both currently run on now. It's irrelevant and will only lead to a horsepower per liter discussion that has been beaten into the ground (multiple times) already.

The bottom line is if people on both sides of the rotor vs piston argument would stop giving a shit what OTHER PEOPLE did with their cars, there would be no reason to argue. But since that will never happen, people will continue to voice their opinions and take shots at the opposing argument. It makes your balls grow exponentially to insult strangers over the internet. Sooner or later we'll all be walking like cowboys.

I think this statement hits the nail right square on its round head. It boils down to the personal enjoyment of not only driving thier cars, but modifying them to their own taste. Just think, if everyone had the same car with the same engine, how boring would that be. Building stock engines into high performance machines has been around since the beginning of automobiles. Transplanting engines from other cars has been around just as long. I like cars and I like to drive. I like all different types of engines. I don't like haters, people who bash other people because they like or use a different type of engine.

If its your car, do what you want with it. If it is not your car, You can't do anything with it, except try to out perform it. If you can, great, if you cant, don't cry about it. Fix it so it will, or join the other side.

Later,
Bill

nice.

One thing I really enjoy about a rotary-
- I can rebuild it in a weekend
-never have to drop my block off at a machine shop to do it right, and wait 6 months to get it back.
-Or run race gas to make good power n/a.
-Never have to drop off my head to be decked after a overheat
-Never have to drop off my valves and head to have a 5 angle valve job
- I dont have to consider what type of valve springs to use, what type of compression, rings, seats, lifters, rods, headgaskets ect.
- All this makes a rotary a vacation to work on FOR ME!

you consider 200hp n/a good power?

He's running more than 2 rotors.

if hes running a 3 rotor then i doubt hes making over 300hp n/a