So, Ive been thinking Wankel....

Kelly · Post by **Kelly** » Sat Nov 17, 2007 7:47 am

Weve got an 87 RX7 thats been sitting in our garage down here that the customer has pretty much abonded. It was diagnosed with bad apex seals like a year ago, been sitting ever since. Its got an assload of miles on it and probablly needs a motor rebuild.

My question is, has anyone here had any experiance with rotaries?

I have no experiance with them, and it looks like rebuild kits arent really that cheap.

beatersubi · Post by **beatersubi** » Sat Nov 17, 2007 8:02 am

My brother in law just sold his rx7(FC). His apex seals were going. From what I understand, they're a PIA to keep running right. But when they do...its an impressive amount of power from a very small displacement. Especially the turbo'd ones.

tris91ricer · Post by **tris91ricer** » Sat Nov 17, 2007 1:15 pm

I've worked on one for my buddy Chris (awdwagon) . In fact, he's driving one right now since he sold his tleg (again!).

They suck balls. PITA to work on, and so many things go wrong with them, they're not worth it. If rotaries were gonna catch on, they would have already. It's a nice concept for a way to make hp, but the reliability isn't there, and neither is the longevity. Not to mention the lack of decent gas mileage for something that's only 1.3L.
Apex kits can be had for about a couple hundo, Kelly.

206er · Post by **206er** » Sat Nov 17, 2007 4:08 pm

the best fix for a rotary is to pull it out and put a V8 in.
seriously though, i heard you can get one with bad apex seals to start by pouring some oil down the intake, helps em build pressure or something.
rotaries are cool in a way but not a car I'd ever mess with. maybe an RX3.

Kelly · Post by **Kelly** » Sat Nov 17, 2007 9:09 pm

Well, there really really light and RWD which is godda be fun. I kinda got hooked on the FR thing after I had that Porsche, cept it was completelly gutless. My buddy in LA has an old 912 with the 13b in back. Powerband much like a turbo car I thought and was smooth as hell.

The v8 swap looks like a PITA. There are a couple kits available, but the kits themselves arent really that cheap either, and I bet a V8 swap would prolly run somewhere around the 3K range when all said and done.

Ive been searching around the webs for some sort of write up, or exploded veiws of the motor itself to get an idea of how big of a project it is to rebuild one. Thought Id ask you guys first since some of you seem to have experiance in many other makes and modles and wouldn't instantlly reply to me with a "um, just search dood".

Anyway, just thinkin out loud I suppose.

Gracias!

555BCTurbo · Post by **555BCTurbo** » Sun Nov 18, 2007 1:47 am

Badass

tris91ricer · Post by **tris91ricer** » Sun Nov 18, 2007 1:22 pm

Rotaries are so "badass", they don't run everyday.

beatersubi · Post by **beatersubi** » Sun Nov 18, 2007 6:41 pm

555BCTurbo wrote:Badass

tris91ricer wrote:Rotaries are so "badass", they don't run everyday.

...here we go

entirelyturbo · Post by **entirelyturbo** » Wed Nov 21, 2007 3:23 am

91turbogsx · Post by **91turbogsx** » Sun Nov 25, 2007 3:40 am

Rotary's were built with magic inside them and once you open them up the magic escapes and unless your a magician you'll never get it back.

Much like automatic transmissions.

Don't let all the negative opinions change your decision though. They can be very fun. Plus when you are working on them you feel like a rocket scientist when you know a little bit about what your doing. As long as you are on top of the engine vitals things should be fine and you should get quite some miles of fun with it.

NA rotaries are far more reliable than the turbo ones and that is what most people base their opinions off of. Plus most of the guys here drive Subaru's and they are used to going 200+ thousand miles. Rotary's won't last you quite that long.

Arctic Assassian · Post by **Arctic Assassian** » Mon Nov 26, 2007 11:12 pm

great picture.

BXSS · Post by **BXSS** » Wed Nov 28, 2007 1:31 am

Rotaries are probably the only motor on the planet were starting out with a 100bhp stock motor, a porting set-up, some scrap aluminum tubing & some 2 part epoxy you can produce a 270HP 12,000+ RPM N/A monster with the proper knowledge.

I've seen my buddies pull a motor rebuild it & put it back in the car & have it running in 3-4hrs, which I think is amazing.

I've also seen them buy, then start cars & run cars that were diagnosed as dead by mechanics - to the now previous owner's amazement.

They also say stock motors do not make any power & that the motor needs to be opened up & ported to make some HP.
If real power is needed then a turbo must be added to the equation.
I believe the best N/A time on my buds Starlet was 11.0 in the 1/4, like 15+ years back.

But like anything else if you do not know what your doing these motors can be a nightmare.

I believe 1.3l turbo rotaries are up to 1500WHP on methanol.
So boost in does not mean apex seals out (nice pic though).
Apex seal damage (warpage or breakage) is caused by detonation, which will destroy a piston motor as well (cracked pistons, holed pistons, bent rods, cracked blocks....) . Its all on the set-up.

When they do blow motors its usually not dramatic at all, the car just will never start again its either a bearing (seized motor) or an apex seal (which weighs all of 14 grams for iron, or 5.5g for ceramics) warped or cracked.
No big deal my buds can fix it in 4 hours or less!

jamal · Post by **jamal** » Wed Nov 28, 2007 1:57 am

I saw a really cool rotary at a car show in Long Beach recently:

Also this:

Also I am secretly in love with rotaries.

evolutionmovement · Post by **evolutionmovement** » Wed Nov 28, 2007 3:28 am

The only Japanese car to win LeMans. They had problems with melting exhausts, IIRC. I like the idea of them and the simplicity, but I personally don't like anything that's not robust and they consume lots of fuel and oil as well as being nasty polluters. But then, I'm designing my own car with slippery aerodynamics and light weight with an S2000 drivetrain, but gearing it up so that it 6th gear runs almost 33 mph/1000 rpm and aiming for 50+ mpgs instead of the sub 3-secs 0-60s that most people would go for instead so I know I'm strange.

G-reg · Post by **G-reg** » Wed Nov 28, 2007 5:28 am

Wow, that turbo is engined.

beatersubi · Post by **beatersubi** » Wed Nov 28, 2007 5:54 am

Yeah... the theory of operation behind a rotary is pretty neat. But the reality is that the newest, best rotary on the road doesn't make much power, even less torque, and gets horrible milage at the same time.
It makes for a great track car, though.
But maybe thats where they belong.

AWD_addict · Post by **AWD_addict** » Wed Nov 28, 2007 6:14 am

beatersubi wrote:It makes for a great track car, though.
But maybe thats where they belong.

Probably so. From the RX-7 owners I've talked to, I get the feeling that rotaries are eternal projects.

tris91ricer · Post by **tris91ricer** » Wed Nov 28, 2007 6:59 am

It's even worse when the owners won't keep they meddlin' hands out from under the hood! Believe me, that's how it all got started. That and E-Bay!

BXSS · Post by **BXSS** » Wed Nov 28, 2007 6:52 pm

I guess the same meddling happens to all cars, I know my Legacy is not stock.

RX7 owners I know do tend to be fanatics & not bothered by rebuilds, I guess the motors are just that good to them.

I do not see myself driving a rotary car - they wasted too much gas, but I must give them credit for being a cost effective powerplant with alot of untapped potential.

Our budget drag car runs 9.9s on the 12a - 1100cc "little" motor on a 18 wheeler free-bee turbo, & is all spare/old parts internally with a kick ass port job & 20psi of boost.
http://bbs.legacycentral.org/viewtopic.php?t=32633
Motor runs well, but we did explode a flywheel.

Kelly · Post by **Kelly** » Wed Nov 28, 2007 9:57 pm

G-reg wrote:Wow, that turbo is engined.

Ha, I just ROFLed.

My whole point of owning a car like this is not for longetivity or economy. I just see the rotary as a challenge. I dont need another daily driver, I do however need something cheap and fun to go out and beat the hell out of.

Theres a couple of "how to" videos for rebuilding em for like $20. A good way to start me thinks, but rebuild kits are freakin spendy! Jeez, I thought Subaru parts were expensive.

I dont need one with a turbo either. Price will just go up, a lot. And Id hate to dump a bunch of pesos into something I'll prolly just put into a ditch anyway.

You know, you guys aren't my real mom anyway!

evolutionmovement · Post by **evolutionmovement** » Wed Nov 28, 2007 10:24 pm

Grass Roots Motorsport built a Spitfire with a rotary a few years back that was pretty cool.

555BCTurbo · Post by **555BCTurbo** » Thu Nov 29, 2007 1:01 am

Kelly wrote:
G-reg wrote:Wow, that turbo is engined.
Ha, I just ROFLed.

My whole point of owning a car like this is not for longetivity or economy. I just see the rotary as a challenge. I dont need another daily driver, I do however need something cheap and fun to go out and beat the hell out of.

Theres a couple of "how to" videos for rebuilding em for like $20. A good way to start me thinks, but rebuild kits are freakin spendy! Jeez, I thought Subaru parts were expensive.

I dont need one with a turbo either. Price will just go up, a lot. And Id hate to dump a bunch of pesos into something I'll prolly just put into a ditch anyway.

You know, you guys aren't my real mom anyway!

You should do it Kelly...you have t3h mAd sKilLz!

entirelyturbo · Post by **entirelyturbo** » Thu Nov 29, 2007 3:15 am

G-reg wrote:Wow, that turbo is engined.

Posterity

.

beatersubi · Post by **beatersubi** » Thu Nov 29, 2007 6:13 am

Kelly wrote:You know, you guys aren't my real mom anyway!

Do whatever you want then, see if I care!

I do think it'd be fun to see what effect on power playing with 'valve timing', just by changing intake and exhaust ports, would have.

BXSS · Post by **BXSS** » Thu Nov 29, 2007 2:08 pm

Racing Beat sells rebuild kits & porting templates.

If the apex seals are bad you can get away with changing them & the rotor housing o-rings & the car will run.

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So, Ive been thinking Wankel....

So, Ive been thinking Wankel....