/o/ - Auto » Thread #4637539

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98KiB, 640x480, unknown.jpg

Anonymous Tue 03 May 2011 03:31:00 No.4637539 View View Reply Original Report

Quoted By: >>4637544 >>4637564 >>4637569 >>4637589 >>4637597

I'm American, don't believe in rice, and I buy American, buy my question is: Why don't more cars use rotary engines instead of pistons and cylinders?

For example:

A 1994 Mazda RX-7 is a 1.3L Rotary, Twin Turbo.
0-60 in about 6 seconds.
158 mph top speed.
17 City / 25 Highway MPG.
225 HP

A 1994 Ford Mustang GT, 5.0L V8, N/A
0-60 in 6.6 seconds.
Around 140-145 MPH top speed
15 City/23 Highway MPG
225 HP

dead !!1w3SeuwCso0

dead !!1w3SeuwCso0 Tue 03 May 2011 03:32:00 No.4637541 Report

Quoted By: >>4637546

mazda

>drive 3k miles
>lolapexseals

ford

>slap a turbo on it
>run 9s

Anonymous

Anonymous Tue 03 May 2011 03:32:00 No.4637542 Report

Quoted By: >>4637546 >>4637552

because they eat up oil like crazy. also it's not the motor thats light, it's the car itself. throw that 1994 rx7 rotary twin turbo set up in that mustang and you will not have those speeds

Anonymous

Anonymous Tue 03 May 2011 03:33:00 No.4637544 Report

Quoted By: >>4637549 >>4637554

>>4637539
>pic
Sweet for Sierra brah

Anonymous

Anonymous Tue 03 May 2011 03:33:00 No.4637546 Report

Quoted By:

>>4637541
>>4637542
Acceptable, thanks.

Anonymous

Anonymous Tue 03 May 2011 03:33:00 No.4637547 Report

Quoted By:

apex seals last a long time so long as they are used at the specified boost range... as soon as you really crank up the boost thats when they break up, it's like rods breaking in a motor because they are the weakest link.

Anonymous

Anonymous Tue 03 May 2011 03:35:00 No.4637549 Report

Quoted By: >>4637551

>>4637544
What?

Anonymous

Anonymous Tue 03 May 2011 03:35:00 No.4637551 Report

Quoted By: >>4637553 >>4637554

>>4637549
Replace "for" with "Ford"

Overboard and Self-Assured !!yvm0QrHZZJQ

Overboard and Self-Assured !!yvm0QrHZZJQ Tue 03 May 2011 03:36:00 No.4637552 Report

Quoted By:

>>4637542

>it's not the motor that's light

The engine itself is light, it's the sequential twin turbo setup that weighs a lot. You can save weight and reduce heat soak in a 13b-rew by converting to single turbo. Since rotaries spool turbos so fast anyways drivability won't be compromised much.

anyways the rotary engine made the FD fast on a track. this is because they were compact and could be mounted lower and further back than a traditional engine giving a better weight balance and lower center of gravity. (this is why a LSx swapped FD will not handle like stock, ever, even though the LSx probably weighs almost exactly the same as a 13b-rew_

Anonymous

Anonymous Tue 03 May 2011 03:38:00 No.4637553 Report

Quoted By:

>>4637551
That's a Foxbody Mustang.

dead !!1w3SeuwCso0

dead !!1w3SeuwCso0 Tue 03 May 2011 03:38:00 No.4637554 Report

Quoted By:

>>4637551
>>4637544
>new
>european

get your ass outta here

Anonymous

Anonymous Tue 03 May 2011 03:38:00 No.4637556 Report

Quoted By:

a 5 liter rotary would be rediculously large and if you were going with that much displacement it would be an 8 rotor engine not a 4 the 1.3 liter is a 2 rotor engine

Overboard and Self-Assured !!yvm0QrHZZJQ

Overboard and Self-Assured !!yvm0QrHZZJQ Tue 03 May 2011 03:42:00 No.4637564 Report

Quoted By:

>>4637539

also as for the 5L rotary engine

each rotor is 652cc (I might be wrong, thats off the top of my head)

the 2.0L 20B-REW is a triple rotor
the 1.3L 13B-REW is a 2 rotor

although you can in theory just stack rotors/housings and make a 1 bajillion rotor engine, you can't make one that will last more than 30 seconds. the eccentric shaft (crank, basically, but for rotaries) would snap. not to mention that a 10 rotor or whatever would be ridiculously long. tuning companies like scoot sports have made 4 rotor engines though, youtube it.

Reverend !!u0V4bkDcBzt

Reverend !!u0V4bkDcBzt Tue 03 May 2011 03:44:00 No.4637568 Report

Quoted By: >>4637601

I assume you're talking about why you don't see more in America, so my answer caters to that.

Here, there're two main reasons:

1) Emissions. Rotary engines inherently burn a little oil, which means more particulate in the exhaust. By the current emissions standards, that's a big no-no.
1a) Fuel economy - Rotaries get *shit* economy for their power production. Just look at the power/torque curves from a stock RX-8 vs their real-world mpg numbers. No, numbers aren't everything, but it's hard to justify a car that gets 18mpg with 240hp when you can buy a car that gets 25mpg with 300hp for $5k less.

2) Torque. Rotary engines make it, but they do so at high rpm. The typical American driver is deathly afraid of actually spinning their motor, so rotary engines come across as totally gutless. This is the same reason that most of the Japanese sport compacts got "Americanized" during the late '70s and early 80s, and did so by replacing a high-rpm motor with a larger-displacment lower rpm one (SR20 vs KA24, 18RG vs 22R, 2TG vs 3T-C, 3SGE vs 5SFE, RB20 vs VG30E).

Anonymous

Anonymous Tue 03 May 2011 03:44:00 No.4637569 Report

Quoted By:

>>4637539
>Why don't more cars use rotary engines?

Because they're fucking shite

Anonymous

Anonymous Tue 03 May 2011 03:44:00 No.4637570 Report

Quoted By: >>4637690

lol gas mileage

lol high maintenance

lol apex seals

lol notorks

K Series !!luBNga8XM2+

BUY KAWAII NEVER LOOK BACK

K Series !!luBNga8XM2+ Tue 03 May 2011 03:50:00 No.4637589 Report

Quoted By: >>4637606

>>4637539
I'll go ahead and say that while my boy Felix INVENTED the Wankel rotary, it took Mazda to polish it to the point it's at today. That's like saying that Mustang engines are French because Alphonse Eugène Beau de Rochas (according to wiki) first patented the four-stroke engine.

Anonymous

Anonymous Tue 03 May 2011 03:53:00 No.4637597 Report

Quoted By: >>4637599 >>4637620

>>4637539

Ford are ok if:

>you don't mind bullshit performance and hp figures
>you don't mind the speedo adding around 10% on for luck
>you don't mind rattles and soft metal
>you don't mind constant minor repairs

I know a dude whose RX7 has cost him £200 a year servicing for nearly ten years. Another guy's Ford cost at least double that for the last three years, and it's a newer car.

henry_ford !T/cybz7iao

henry_ford !T/cybz7iao Tue 03 May 2011 03:54:00 No.4637599 Report

Quoted By:

>>4637597
>i know a guy, i also know another guy
cool story bro, is that really how you decide which automakers are reliable?

Overboard and Self-Assured !!yvm0QrHZZJQ

Overboard and Self-Assured !!yvm0QrHZZJQ Tue 03 May 2011 03:54:00 No.4637601 Report

Quoted By: >>4637624

>>4637568

GM and Nissan (Datsun at the time) both had running, driving wankel concepts in the 60s or 70s. I don't really remember. GM scrapped it because they had to choose between fuel economy and reliability. They made it perfectly reliable but it got shit fuel economy, they changed some shit, it all went to hell and was no longer reliable. Then the gas crisis of the late 70s came up just when it was about to be released and they said to hell with it.

Anonymous

Anonymous Tue 03 May 2011 03:55:00 No.4637606 Report

Quoted By:

>>4637589
I could be wrong, but I'm pretty sure Daimler made it first. If you're ever wary of the inventor of any item, chances are it's German.

Anonymous

Anonymous Tue 03 May 2011 04:01:00 No.4637620 Report

Quoted By: >>4637702

>>4637597
I also know a few guys who had their Ford Pickup last 350k+ miles. I also know a relative (my grandfather), who had a 1972 Dodge Monaco Wagon with a 318ci (5.2L V8) that lasted 400k+ miles, couldn't be driven father because he lived in Chicago and the winters take a violent toll on the body, therefore it rusted out.

So what's your point?

Reverend !!u0V4bkDcBzt

Reverend !!u0V4bkDcBzt Tue 03 May 2011 04:02:00 No.4637624 Report

Quoted By: >>4637639

>>4637601
Don't know about Datsun, but I know GM did, the Vega was originally intended to use a rotary, and there was at least one rotary Corvette concept (which I believe was mid-engined and used a 4-rotor); I know either the Pacer or Gremlin was originally designed around using a rotary; and the Delorean was designed with a 3-rotor in mind.

Overboard and Self-Assured !!yvm0QrHZZJQ

View Same Google ImgOps iqdb SauceNAO unknown.jpg, 117KiB, 338x500

Overboard and Self-Assured !!yvm0QrHZZJQ Tue 03 May 2011 04:05:00 No.4637639 Report

Quoted By: >>4637656

>>4637624

Datsun had a 1200 sedan rotary concept and working prototypes. i've also heard it was put in old, old silvias.

pic related but you cant fucking read it because low res

random anon !!Jt9Sk1+N31W

View Same Google ImgOps iqdb SauceNAO unknown.jpg, 259KiB, 1280x1122

random anon !!Jt9Sk1+N31W Tue 03 May 2011 04:07:00 No.4637649 Report

Quoted By:

Overboard and Self-Assured !!yvm0QrHZZJQ

View Same Google ImgOps iqdb SauceNAO unknown.jpg, 351KiB, 1104x1632

Overboard and Self-Assured !!yvm0QrHZZJQ Tue 03 May 2011 04:08:00 No.4637656 Report

Quoted By:

>>4637639

here we go

Anonymous

Anonymous Tue 03 May 2011 04:16:00 No.4637690 Report

Quoted By: >>4637705 >>4637779

>>4637570

it's like nobody on this board understands torque and its relationship to power

Anonymous

Anonymous Tue 03 May 2011 04:18:00 No.4637702 Report

Quoted By: >>4637773

>>4637620

that Fords are cost reduced and as such are always breaking. by the time a Ford has got to 350 thousand, it's cheaper to finance a new car than keep that thing in anything close to roadworthy condition. i'll bet it was one pile of smoking oil and bodged repairs (and did 13 mpg)

Anonymous

Anonymous Tue 03 May 2011 04:19:00 No.4637705 Report

Quoted By:

>>4637690

You spelled "torks" wrong.

Ford apprentice !5zb/EKX0ks

Ford apprentice !5zb/EKX0ks Tue 03 May 2011 04:31:00 No.4637765 Report

Quoted By:

>94 fd
Isn't that suppose to be considered higher end than the gt of that year. I thought it was more of a competitor to the corvette.

Anonymous

Anonymous Tue 03 May 2011 04:33:00 No.4637773 Report

Quoted By: >>4637817

>>4637702
If you think Fords are the only vehicles out there that are "cost reduced", you're smoking stronger shit than I care to even be around. Especially if you're comparing them to another mass production company like Mazda. Especially fucking Mazda, considering the close relationship and parts-sharing that occurs between Ford and Mazda (i.e. cars that are FUCKING IDENTICAL other than sheet-metal, like the MX-6/Probe, Escort/Protege, Ranger/BXXXX, Fusion/6, Focus/3, etc, etc, etc)

Ford apprentice !5zb/EKX0ks

Ford apprentice !5zb/EKX0ks Tue 03 May 2011 04:34:00 No.4637779 Report

Quoted By:

>>4637690
Yea, no kidding. I especially hate how no one understands the relationship between the engine and the transmission and how it multiplies torque.

HowITripCode? !!DU22SQMj6dQ

HowITripCode? !!DU22SQMj6dQ Tue 03 May 2011 04:41:00 No.4637799 Report

Quoted By:

>Why don't more cars use rotary engines

lolapexseals

Anonymous

Anonymous Tue 03 May 2011 04:46:00 No.4637814 Report

Quoted By:

Rotaries are terribly inefficient in a thermodynamic sense. Nothing you can do aside from developing ceramic blocks and rotors will solve this.

Think about it for a second and you'll understand why. In a piston engine the piston and head share both the cooling intake of air and heat producing combustion. In a rotary only 1/3rd of the housing (analogous to the head) is exposed to the uncompressed intake charge and 1/3rd of the housing is always experiencing compression and combustion. Heat localizes in dramatic fashion.

That extremely hot face is why rotaries run low compression ratios compared to pretty much anything else that requires high octane fuel, it causes knock issues. The Renesis has a 10:1 ratio which is the same as the 2.0l Mazda3 which runs on 87 octane.

American Focus Owner !!Kyo8bWKHhkp

American Focus Owner !!Kyo8bWKHhkp Tue 03 May 2011 04:46:00 No.4637817 Report

Quoted By:

>>4637773
>you're smoking stronger shit than I care to even be around.

lulz

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