Rotary Engines

[d-UNiT]

look at my profile. yes i am a newb!.. i am willing to admit that.. but i was just wondering.. why people are warning me not to get an old mazda due to the rotary engine.. what makes it so dangerous or less favourable than another kind of car.. i was told that if i got an old one i would have to do constant tune ups .. and i would have problems that sounded like a real turn off.. i was just wondering if any of you could clarify some faqs.. or info about the rotary engine more specifically in an 81-88 rx7.. thanks in advance.. and also.. is it more fuel effiecient?.. cuz fuel economy is very important for me when thinking about a car purchase (student)

[Weapon_R]

rx-7's are very hard on gas.

The rotary must be cared for, moreso than a regular engine. Too many people neglect this, and the car ends up with some major problems.

[pr0]

Viper gas consumption :rofl: Extra care for the engine. Not easy to maintain... blah blah :D

[Team_Mclaren]

from what i've heard is, if u dont know it (rotary) stay away from it! especially the older ones...:dunno:
but then again its a MAZDA!!!:D

[Go4Long]

81 - 88 RX7? you are spanning two different generations there...up till 85 is the FB/SA22C depending on what continent you are on...86-88 is Series 4 FC, 89-92 is series 5 FC, 93-96 is series 6(or FD if ya prefer).
On boost my FC gets horrible gas mileage...if I drive like a white person however, a tank of gas will last two weeks no problem. despite it being classed as a 1.3 L, keep in mind that rotaries work on a different principle than normal reciprocating engines, and are actually more similar to a 2.6 L in terms of exhaust gasses pushed and what not.

If not properly tuned, or if you boost the hell out of it, you will blow your rotary up, no questions, it'll happen.

On the plus side, they are a lot of fun...I love my car, even with all the headaches I have had with it I still love it. the turbos are quick, capable of hitting low 14's easily on stock turbo stock block(I hit 13.940, but apparently that is unheard of)

[d-UNiT]

thanks for the help.. anyone like to translate what he just said lol

[method]

they're not great engines to have if you dont know anything about them/arent willing to learn.

just like a 2 stroke motorbike would be bad to purchase if all you ever rode was 4 strokes, and you werent willing to learn about the 2..

[d-UNiT]

right

[Xtrema]

BTW, anyone specialize in Rotary in town?

Got a kid who thought FC is cool because he watches Initial-D. Goes out and buy one after numerious attempt to tell him to stay away.

Got one and the engine is gone in less than a year.

Now it need a rebuild and he's doesn't have much cash to start with. So all he got is just a dead shell not going anywhere and still paying killer insurance on.

So unless you have $$$ and a good mechanic, stay away from rotary.

[d-UNiT]

rx-7 specialties... but thats all i know.. why would he keep paying insurance on it if he doesnt drive it:banghead: .. and whats an fc?

[Weapon_R]

Originally posted by Xtrema
BTW, anyone specialize in Rotary in town?

Got a kid who thought FC is cool because he watches Initial-D. Goes out and buy one after numerious attempt to tell him to stay away.

Got one and the engine is gone in less than a year.

Now it need a rebuild and he's doesn't have much cash to start with. So all he got is just a dead shell not going anywhere and still paying killer insurance on.

So unless you have $$$ and a good mechanic, stay away from rotary.

If he doesn't have the $$$, he might as well get a new car. Engine rebuilds at rx-7 specialties are very expensive.

[Akagi Redsuns]

Originally posted by Go4Long
snip.........., 89-92 is series 5 FC, 93-96 is series 6(or FD if ya prefer)...........snip

Just FYI, no such thing as a 1992 RX-7 in North America and in 1992 it would have been a FD3S and the last year of the FD in North America is 1995, but it went beyond in Japan of course.

[Akagi Redsuns]

Originally posted by d-UNiT
rx-7 specialties... but thats all i know.. why would he keep paying insurance on it if he doesnt drive it:banghead: .. and whats an fc?

FC is the short designation of chassis code FC3S, which applies to the 1986-1991 version of the Mazda RX-7.

Just like the S13/S14 designations for Nissan 240SXs, SW20 for Toyota MR2s, AE86 for the mid 80's Toyota Corolla, .........you get the picture :)

[rx7_turbo2]

Originally posted by Xtrema
BTW, anyone specialize in Rotary in town?

Got a kid who thought FC is cool because he watches Initial-D. Goes out and buy one after numerious attempt to tell him to stay away.

Got one and the engine is gone in less than a year.

Now it need a rebuild and he's doesn't have much cash to start with. So all he got is just a dead shell not going anywhere and still paying killer insurance on.

So unless you have $$$ and a good mechanic, stay away from rotary.
If you read various car forums you'll find this type of thing is a regular occurance for ALL motors. There's always a kid buying a DSM and then blowing it up shortly after. Because the rotary motor is different when the engine goes it gets the blame, often a piston motor in the same senario is just as likely to go. The engine does have some week points. Coolant "o" rings can become a problem, it would be like blowing a head gasket on a piston motor, except it requires a total rebuild.

You get stuck in the same old senario. You already have the motor apart so you might as well replace a bunch of parts with new parts while your in there. A practice that should be done on all engine rebuilds really. That can bring the price of the rebuild up. But a proper piston motor rebuild will encounter the same senario. This is all compounded by the fact very few people actually rebuild the motors, and even fewer rebuild them well. And just like places that rebuild piston motors, rotary builders often like to tack on extra's that bring the cost up, porting, 3mm seals:( etc. Now with that said if you check the rotary forums you'll find there's ALL kinds of info on how to rebuild them yourself, lots of very detailed video's on the proccess. On the RX-7 forum there has been a ton of people with limited to zero knowledge on the motor rebuild them succesfully.

The parts microfiche can be dowloaded and if you have the parts number gasket kits and seal kits can be bought direct from mazda.

The engine does at times require the owner to do some research about how it works and issues regarding how it works and runs. But if your a newbie to cars you would have to learn all about a piston motor anyways so it's not alot of extra work. Rotary powered vehicles are fun, and it's nice to be involved in a community that's a little bit different than the rest.

[d-UNiT]

Thanks for the input guys!....

[d-UNiT]

oh and rx7_turbo2
... do you have pictures of your car.. and ewwwww your display pic is naassty :guns: :guns:

[510wagon]

turbo rotaries are somewhat fragile compared to piston engines; a single detonation could destroy the apex seals or worse. but most of the bad rep that rotaries get is from the early 70's when it was brand new and had very little development. due to this fact was crude and unreliable. it was also classified as a 1.0 liter engine (the 10A), but is really more like double that, so when it consumed gas like a 2 liter everyone thought it was a 1 liter with horrible gas mileage. this was compounded by the fact that we were entering the big fuel crisis of that era, so the reputation stuck. also, rotaries like to be run at high RPM, so at idle the fuel mixture has to be set a bit higher than it would for a piston engine (especially when using carb's), thereby killing efficiency. the other half of its reputation for being unreliable is from the TT FD3S. don't get me wrong, its one of the greatest cars ever produced, but its sequential twin turbo system is rather complex and used a whole lot of vacuum lines routed all over the engine to operate the turbos. rotaries get really hot and if left to their own will, the critical (and apparently suicidal) vacuum lines sit very close to the engine. so after a while, one or more of these lines will melt or crack, lose vacuum, confuse the ECU and destroy the engine. on top of that, you have to be very deliberate when modifying these engines. for example, rotaries are a lot louder than piston engines when they aren't muffled (no valves or cylinder head to slow the exhaust's exit from the combustion chamber), so mazda equips RX7's with very restrictive exhaust systems to counteract this. so if you do the typical intake/header/exhaust swap on an RX7 you will increase the airflow through the engine so much that it cause a huge boost spike when the second turbo kicks in, thereby overtaxxing the fuel system and causing detonation, which, as stated earlier is a sure fire way to kill a rotary. ECU tuning solves this, but if you go a little further, the afore mentioned characteristic of being extremely hot comes into play and the cooling system can no longer keep up with the demands put on it, so it overheats, melting various vital seals within the engine. now, with all this talk about potentail weaknesses, you'd probably assume i hate rotaries and will tell you not to get one. wrong. i love rotaries (probably more than is healthy) and hope you do get one to enjoy. any RX7 is a great car, but each model has its pro's and con's. first gens are great because they are light, nimble, fun and cheap. however, they are old and were cheap to begin with, so stuff like power windows and locks, cruise control are probably either not equipped or don't work. if you can find a '85 GSL-SE model, you also get the fuel injected 1308cc 13B instead of the carburated 1154cc 12A, about 30hp more, independent rear suspension, four whhel disc brakes and a limited slip diff. good luck on that one though; they're kinda rare. second gen's (FC3S) are probably the best performance value. all the extras from the GSL-SE are standard on FC's, and there is also a turbo model available. the turbo models are a little finicky (read: unreliable) but the NA version is near indestructible. even the turbo II's aren't too bad though. they just need a rebuild after 100K miles or so. FC's do have rather high-tech, low-quality electrical systems though, so don't expect all the bells and whistles to work. also, both the turbo and NA versions were changed in '89. '86-88 turbo's have 182hp, NA's have 146hp. '89-91's have 200hp for the turbo and 160 for the NA. part of this is due to an increase in compression, so the pre-89 turbo's really have just as much (if not more) potential compared to the later FC's. for this samme reason DO NOT TRY TO TURBOCHARGE A NATURALLY ASPIRATED ROTARY WITHOUT SWAPPING IN ROTORS FROM A TURBO!!! they are considerably higher compresiion and therefor do not get along very well with boost. as far as FD's are concerned, they were only offered as twin turbo. they are one of the best cars ever, but the price and reliability issues are is only major downfalls.