The rotary bike engine.
Discussion
Nobody made it work, sadly, to the point it could be sold in numbers. Was it a bad idea or a missed opportunity?
I am restoring a gen 2 model currently, the version with one set of points rather than 2 and GT750 'kettle' running gear, instruments and lights.
In theory with just 3 moving parts it was the simplest engine out there but in reality with 5 (yes) throttle cables, an engine that ran so hot the exhausts themselves had their own cooling and a carb. so complicated it's about £850 for a new one it was anything but simple.
Values have rocketed lately. Not long ago £4000 got you one, now it's nearer £10,000 and sometimes more. I had one in 2016 and it was unique. Almost big twin-sounding on tick over, then smoothing out to a lovely whine at higher revs.
Missed opportunity or a design that could never work in reality in numbers?
I am restoring a gen 2 model currently, the version with one set of points rather than 2 and GT750 'kettle' running gear, instruments and lights.
In theory with just 3 moving parts it was the simplest engine out there but in reality with 5 (yes) throttle cables, an engine that ran so hot the exhausts themselves had their own cooling and a carb. so complicated it's about £850 for a new one it was anything but simple.
Values have rocketed lately. Not long ago £4000 got you one, now it's nearer £10,000 and sometimes more. I had one in 2016 and it was unique. Almost big twin-sounding on tick over, then smoothing out to a lovely whine at higher revs.
Missed opportunity or a design that could never work in reality in numbers?
Rotary engines have a heavy thirst for fuel in comparison to other IC engines, something Mazda have never been able to resolve and making the concept essentially obsolete now. Considering the Suzuki and Norton rotaries were released around the time of the fuel crisis it's not surprising they went nowhere.
Like everything other than four stroke - lacked development. Rotaries could easily have out performed (they basically did already, if you could work out their volume!) and been better economically had they had a chance. Especially now with modern machining and manufacturing with improved tolerances etc. Not to say the wankel style was the best but had engineers been allowed freedom there would have been evolutions improving economy and durability.
Anyone with a shred of engineering nouse can see the waste of energy starting and stopping a piston to get a revolution of a crankshaft but hey, the steam era got it so right I guess they were super clever!
Anyone with a shred of engineering nouse can see the waste of energy starting and stopping a piston to get a revolution of a crankshaft but hey, the steam era got it so right I guess they were super clever!
Mazda have spent over 50 years plugging away on the concept and, whilst they've cured the reliability woes, they've never dented the thirst. Currently they're investigating it's potential for REX applications as they reckon its compact form lends itself well there but REX has its own glaringly obvious engineering flaw; perhaps they'll deploy it in trailer form, if it ever happens.
hiccy18 said:
Mazda have spent over 50 years plugging away on the concept and, whilst they've cured the reliability woes, they've never dented the thirst. Currently they're investigating it's potential for REX applications as they reckon its compact form lends itself well there but REX has its own glaringly obvious engineering flaw; perhaps they'll deploy it in trailer form, if it ever happens.
Yep but Mazda alone were never going to change people’s views on new technologies. And sadly now with the end of fossil fuel powertrains in sight I don’t think we’ll ever really know what they would be capable of.
Quirkycars1967 said:
...In theory with just 3 moving parts it was the simplest engine out there but in reality with 5 (yes) throttle cables, an engine that ran so hot the exhausts themselves had their own cooling and a carb. so complicated it's about £850 for a new one it was anything but simple...
The development of the Suzuki version of the wankel must have been like a comedy sketch where ever-escalating disasters befall someone who sets out to do one simple job.
EDIT: Why on earth does this forum remove the capitalisation of "wankel"?
Edited by gareth_r on Sunday 18th July 12:32
Fundoreen said:
We had electric motors before any of this rubbish and we will have them again soon.
The wankels lack of character is a step on the way to the souless electric motor so well done to them for that.
Yeah, complete lack of character there...The wankels lack of character is a step on the way to the souless electric motor so well done to them for that.
https://www.youtube.com/watch?v=j-1nKtxZ2Wk
Rubin215 said:
Fundoreen said:
We had electric motors before any of this rubbish and we will have them again soon.
The wankels lack of character is a step on the way to the souless electric motor so well done to them for that.
Yeah, complete lack of character there...The wankels lack of character is a step on the way to the souless electric motor so well done to them for that.
https://www.youtube.com/watch?v=j-1nKtxZ2Wk
The rotary engine is a great idea on paper, just not in the real world. No one have actually made one work properly. Even Mazda, who almost addressed the reliability issues, couldn't make it efficient. Yes, it produced a lot of power when compared to the swept volume but compared to the fuel it was burning, it was pretty damn inefficient.
Quirkycars1967 said:
I just think they could have been a great powerplant. A guy years back in Harrow London had a Van Veen OCR twin-rotor bike. Heaven knows what that would be worth now. I think it had 100 bhp?
Remember that! Some crazy rich Dutchman putting a Mazda rotary engine in a bike. Insanely expensive. I think the Munch Mammoth had an NSU engine also (but not the rotary). Nuts. And rare as now I should imagine. Fundoreen said:
Everyone has a play with that wankel model in the science museum when they are 12 and are convinced they have just observed the cleverest thing ever. No violent up and down Just round and round.
The electric motor is even cleverer,almost like magic but who wants to know eh?
I think one reason might be <checks notes> the mass required to contain the energy source which makes it work.The electric motor is even cleverer,almost like magic but who wants to know eh?
rodericb said:
Fundoreen said:
Everyone has a play with that wankel model in the science museum when they are 12 and are convinced they have just observed the cleverest thing ever. No violent up and down Just round and round.
The electric motor is even cleverer,almost like magic but who wants to know eh?
I think one reason might be <checks notes> the mass required to contain the energy source which makes it work.The electric motor is even cleverer,almost like magic but who wants to know eh?
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