Originally Posted By: Olas
It's "el"' not "le"
See my post above where I said, pardon my fingers.
It's "el"' not "le"
See my post above where I said, pardon my fingers.
Wankle Rotary possible better design
- Thread starter StevieC
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I bought a '73 RX-2 when it was new. Sure enough, five months later it was rebuilt with new seals under warranty with no argument. It then lived a very happy, very revvy, trouble free seven year life until rear ended by some yahoo in a gigantic mid 70's Impala. I can still remember looking in my mirror and seeing the guy talking and *looking* at his passenger before the no-brake 45 MPH impact. Drove the rear bumper to underneath the parcel shelf! The driver's seat back bent, progressively apparently, and I was unhurt. The gas tank didn't even leak. Heck yes, I'd buy another one. Loved the wankel.
My family had rotarys in the 70's. RX-2 was the smoothest car any of us had ever driven, just absolutely near electric car levels of NVH, pretty quick.
RX-4 was the bomb. My dad's 4 speed 74 (or so) was downright quick. Took money from V8 powered cars!
Only one blew up, otherwise fantastic performers when set up correctly...
RX-4 was the bomb. My dad's 4 speed 74 (or so) was downright quick. Took money from V8 powered cars!
Only one blew up, otherwise fantastic performers when set up correctly...
Hard to pass the latest emission, bad fuel economy, apex seal wears, and flooded engine if you do around town short trips.
Piston engines have advanced a lot and are better than rotaries now. Rotary was lighter but now cars are heavier, so engine weight alone doesn't matter as much as before.
Piston engines have advanced a lot and are better than rotaries now. Rotary was lighter but now cars are heavier, so engine weight alone doesn't matter as much as before.
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Originally Posted By: mazdamonky
People got used to not having to top off oil on the motors and never read the instruction manual which very explicitly states this engine is designed to burn a quart every 1k miles. So a lot of people were more than a quart low on oil and not getting proper oil fed to the combustion chamber causing early failure of apex seals.
There was a low oil level sensor on all RX-7/RX-8 ... so anyone who was stupid enough to ignore the warning system forever that the engine was low on oil deserved to blow up their rotary engine.
People got used to not having to top off oil on the motors and never read the instruction manual which very explicitly states this engine is designed to burn a quart every 1k miles. So a lot of people were more than a quart low on oil and not getting proper oil fed to the combustion chamber causing early failure of apex seals.
There was a low oil level sensor on all RX-7/RX-8 ... so anyone who was stupid enough to ignore the warning system forever that the engine was low on oil deserved to blow up their rotary engine.
Originally Posted By: billt460
It seems the rotary engine delivered the absolute worst of everything.
1.) Low horsepower.
It can put out way more HP per liter than any piston engine. Did you see the HP ratings on that 4-rotor race motor - up to 930 HP with 2.6L ... and NO forced induction.
It seems the rotary engine delivered the absolute worst of everything.
1.) Low horsepower.
It can put out way more HP per liter than any piston engine. Did you see the HP ratings on that 4-rotor race motor - up to 930 HP with 2.6L ... and NO forced induction.
Originally Posted By: tom slick
This Wankle sounds awesome in person
With Johnny Herbert himself doing the driving duties!
This Wankle sounds awesome in person
With Johnny Herbert himself doing the driving duties!
Originally Posted By: billt460
Originally Posted By: mazdamonky
.......People decided fuel economy was the most important feature of a car.
I think most people could have lived with the bad fuel economy, if the thing performed. It didn't. It seems the rotary engine delivered the absolute worst of everything.
1.) Low horsepower.
2.) High emissions.
3.) Lousy gas mileage.
1. Low horse power? What? a 1.3 liter motor putting out 232 horsepower naturally aspirated makes it pretty much the highest horsepower per liter naturally aspirated motor ever put into mass production. They did have a low torque to horsepower ratio on the RX8, but it was still a really quick car for what it was. They also had not so great fuel economy for the amount of power they put out.
2. high emissions? 75% of the citizens of the united states don't care about actual emissions values. You could give them a car that gets 70 mpg but puts out more emissions and a non catted 60s model v8 truck per mile driven and they wouldn't care.
3. Gas mileage wasn't lousy, but it definitely wasn't great. A lot of v6 motors around the time putting out similar or less power were getting under 25 mpg freeway.
Originally Posted By: mazdamonky
.......People decided fuel economy was the most important feature of a car.
I think most people could have lived with the bad fuel economy, if the thing performed. It didn't. It seems the rotary engine delivered the absolute worst of everything.
1.) Low horsepower.
2.) High emissions.
3.) Lousy gas mileage.
1. Low horse power? What? a 1.3 liter motor putting out 232 horsepower naturally aspirated makes it pretty much the highest horsepower per liter naturally aspirated motor ever put into mass production. They did have a low torque to horsepower ratio on the RX8, but it was still a really quick car for what it was. They also had not so great fuel economy for the amount of power they put out.
2. high emissions? 75% of the citizens of the united states don't care about actual emissions values. You could give them a car that gets 70 mpg but puts out more emissions and a non catted 60s model v8 truck per mile driven and they wouldn't care.
3. Gas mileage wasn't lousy, but it definitely wasn't great. A lot of v6 motors around the time putting out similar or less power were getting under 25 mpg freeway.
Originally Posted By: philipp10
The problems with the Wankel were oil burning due to seal wear and more importantly, low compression ratio and the low thermal efficiency that accompanies that. They did not get good mpg.
They burn oil BY DESIGN.
12A - 9.4:1
13B - 9.4:1 or 9.7:1
Renesis - 10:1
Not too shabby when compared to its contemporaries. Consider the S2000 with its 11:1 compression ratio - the RX-8 made the same power and torque.
The problems with the Wankel were oil burning due to seal wear and more importantly, low compression ratio and the low thermal efficiency that accompanies that. They did not get good mpg.
They burn oil BY DESIGN.
12A - 9.4:1
13B - 9.4:1 or 9.7:1
Renesis - 10:1
Not too shabby when compared to its contemporaries. Consider the S2000 with its 11:1 compression ratio - the RX-8 made the same power and torque.
The biggest RX8 mistake was in failing to commit to a sportscar. I had owned rotaries before, and owned one when the RX8 dropped, but I didn't really get what the heck it was that I was looking at.
The second mistake was not having a turbo model on the bench, ready to jump in. Once the turbo sport compacts hit the scene, everything without one was never heard from ever again.
Had a turbo sports car been the formula, I have little doubt there would still be an RX8.
It should have gotten direct injection as well. That would have done wonders to combat the thermal efficiency issues.
The second mistake was not having a turbo model on the bench, ready to jump in. Once the turbo sport compacts hit the scene, everything without one was never heard from ever again.
Had a turbo sports car been the formula, I have little doubt there would still be an RX8.
It should have gotten direct injection as well. That would have done wonders to combat the thermal efficiency issues.
Originally Posted By: billt460
Originally Posted By: mazdamonky
.......People decided fuel economy was the most important feature of a car.
I think most people could have lived with the bad fuel economy, if the thing performed. It didn't. It seems the rotary engine delivered the absolute worst of everything.
1.) Low horsepower.
2.) High emissions.
3.) Lousy gas mileage.
1. Low HP - They are not torquey engines - they like to rev. They are purportedly superb when passing on the highway.
2. High emissions - likely. Not sure how Mazda addressed this for the RX8.
3. Lousy gas mileage - yes and no. My friend's uncle summed it up well in the mid-70s, saying of his RX2 "Gas mileage of a 6-cylinder, power of an 8".
The fourth criticism would be longevity. Apparently adding a 2-stroke oil to the fuel does wonders for the apex-seal life.
Originally Posted By: mazdamonky
.......People decided fuel economy was the most important feature of a car.
I think most people could have lived with the bad fuel economy, if the thing performed. It didn't. It seems the rotary engine delivered the absolute worst of everything.
1.) Low horsepower.
2.) High emissions.
3.) Lousy gas mileage.
1. Low HP - They are not torquey engines - they like to rev. They are purportedly superb when passing on the highway.
2. High emissions - likely. Not sure how Mazda addressed this for the RX8.
3. Lousy gas mileage - yes and no. My friend's uncle summed it up well in the mid-70s, saying of his RX2 "Gas mileage of a 6-cylinder, power of an 8".
The fourth criticism would be longevity. Apparently adding a 2-stroke oil to the fuel does wonders for the apex-seal life.
Ford had a lot to do with the mediocrity of the rx8 by their insistance that it meets all 50 state emission regulations.
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I had a 79 RX-7 that Dad and I put on the fiberglass IMSA kit. Such a beautiful car. That thing would simply scream. It was stupid fast. I was blowing away ALL the 280 and 260 Z's. It was so fast, that you didn't really have time to look at the tach, there was a buzzer sound that went off around 7K RPM or so to remind you that you need to shift. With that engine, seemed that the higher RPM's you forced it, it got quicker and looking at some of the graph's, it's true.
Originally Posted By: Number_35
1. Low HP - They are not torquey engines - they like to rev. They are purportedly superb when passing on the highway.
Rotary engines make HP from RPM. HP = (T x RPM)/5252.
Torque at the drive wheels is manipulated through gearing. HP is HP, and rotary engines makes lots of HP per liter, as already mentioned.
1. Low HP - They are not torquey engines - they like to rev. They are purportedly superb when passing on the highway.
Rotary engines make HP from RPM. HP = (T x RPM)/5252.
Torque at the drive wheels is manipulated through gearing. HP is HP, and rotary engines makes lots of HP per liter, as already mentioned.
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