It is an unusual brand and something about that motor is a bit different.
-
Enjoy XS650.com? Consider making a donation to help support the site.
XS650.com receives a small share of sales from some links on this page, but direct donations have a much greater impact on keeping this site going.
This looks a little unusual
- Thread starter gggGary
- Start date
Then you see inside.
Woah.
I wasn't expecting that!
Woah.
I wasn't expecting that!
As a former '88 RX-7 owner, I'm intrigued.
I knew about this,
Hercules W-2000
but not about that.
.
.
Hercules W-2000
but not about that.
.
.
I remembered the Hercules name, but I couldn’t think what for. That crazy rotary street bike. But I never knew they made a dirt bike!
I also can’t believe in all these years, I’ve never heard about that Yamaha prototype!
It looked to be pretty far along in development.
I remember reading an article not that long ago ( maybe Classic Bike mag? ) they got their hands on a couple nice old survivors, a Norton rotary and a Hercules rotary and did a little comparo. It was pretty interesting how different they were. Suzuki probably had the most developed rotary ( if complicated and heavy).
Jay Leno has a good video revue of the Suzuki on Youtube.
I also can’t believe in all these years, I’ve never heard about that Yamaha prototype!
It looked to be pretty far along in development.
I remember reading an article not that long ago ( maybe Classic Bike mag? ) they got their hands on a couple nice old survivors, a Norton rotary and a Hercules rotary and did a little comparo. It was pretty interesting how different they were. Suzuki probably had the most developed rotary ( if complicated and heavy).
Jay Leno has a good video revue of the Suzuki on Youtube.
The dirt version looks like it had a fair amount of get up and went. How did weight compare to conventional 4 strokes?
Suzuki were the only major manufacturer that I recall bringing one to the market
Suzuki RE5
https://www.classicbikeguide.com/suzuki-re5/
Suzuki RE5
https://www.classicbikeguide.com/suzuki-re5/
Very cool !!
Very interesting!
AFAIK, the Hercules bikes were about the only air-cooled Wankels made. It wouldn't be easy keeping those working well I'd guess. Thermal control is the reason that Suzuki went liquid cooling but in the days before CNC machine tools, it wasn't easy to control the machining of the combustion chamber shapes. Apparently, it nearly sank Suzuki at the time.
I had a good chat with a former Mazda R&D guy some years back after their difficulties with the RX8 sports car (they had a to replace a large number of engines that were fairly new but wore out to the point where they didn't run). He told me that the problem was that some of the engines seemed to last forever with virtually no wear at all while in others, the rotor tip "apex" seals would wear out within a few thousand miles. They did endless testing and metallurgical examination work but never really figured out why this was happening. The problem, aside from the cost to Mazda, was that once they gave the customer a new engine, the car was no longer "numbers matching" and the collectors didn't want them so the resale values dropped fast and the reputation of the car was weak. Too bad - it was a cool car IMO.
Along with the manufacturing and durability issues, the fundamental problem with the Wankel is poor thermodynamics: the volumetric efficiency is not that high and so fuel consumption is poor and also, they had to inject tiny amounts of oil into the combustion chamber to lubricate the apex seals and that oil was burned along with the air-fuel mixture, and consequently, exhaust emissions were also quite high. This meant that they needed big catalytic converters (i.e. lots of platinum so $$$$) and it brought down Mazda's CAFE (corporate average fuel economy) ratings.
Too bad, because the Wankels run very smoothly and produce lots of power on small displacements.
AFAIK, the Hercules bikes were about the only air-cooled Wankels made. It wouldn't be easy keeping those working well I'd guess. Thermal control is the reason that Suzuki went liquid cooling but in the days before CNC machine tools, it wasn't easy to control the machining of the combustion chamber shapes. Apparently, it nearly sank Suzuki at the time.
I had a good chat with a former Mazda R&D guy some years back after their difficulties with the RX8 sports car (they had a to replace a large number of engines that were fairly new but wore out to the point where they didn't run). He told me that the problem was that some of the engines seemed to last forever with virtually no wear at all while in others, the rotor tip "apex" seals would wear out within a few thousand miles. They did endless testing and metallurgical examination work but never really figured out why this was happening. The problem, aside from the cost to Mazda, was that once they gave the customer a new engine, the car was no longer "numbers matching" and the collectors didn't want them so the resale values dropped fast and the reputation of the car was weak. Too bad - it was a cool car IMO.
Along with the manufacturing and durability issues, the fundamental problem with the Wankel is poor thermodynamics: the volumetric efficiency is not that high and so fuel consumption is poor and also, they had to inject tiny amounts of oil into the combustion chamber to lubricate the apex seals and that oil was burned along with the air-fuel mixture, and consequently, exhaust emissions were also quite high. This meant that they needed big catalytic converters (i.e. lots of platinum so $$$$) and it brought down Mazda's CAFE (corporate average fuel economy) ratings.
Too bad, because the Wankels run very smoothly and produce lots of power on small displacements.
Last edited:
Going through some stuff and came across this
https://www.visordown.com/features/top-10s/top-10-wankel-engined-bikes#ixzz3Zjw05JkX
https://www.visordown.com/features/top-10s/top-10-wankel-engined-bikes#ixzz3Zjw05JkX
Max Midnight
XS650 Addict
Ahhh yes - quite right Max. I am not very familiar with those - did they ever sell any on the retail market?
Pete
Here’s a video of the track bike. First two minutes they’re just talking about the bike, sound begins at 2:15 minutes in. It sounds very much like a two stroke.
Yes, but very few. Sort of an answer in search of a question.
Very much like the Suzuki RE5. Aside from being heavier, more complicated and thirstier than any other bike, it was also more expensive.
Aside from those issues, it was a superb machine.
Max Midnight
XS650 Addict
A bit more info here Pete and if you really want to find out more about them how about this?
A friend of mine worked at Norton and took me for a ride on one of the test mules.
It was incredibly smooth and performed well.
We had to cut our ride short as it dropped onto on cylinder or should that be rotor?
What was impressive is that it continued to ride well but with less power than before and was able to take two quite large lads back to base without any fuss.
On the odd occasion that my Bonneville tried the same trick it was a right pig, much slipping of clutch and complaining of motor.
A friend of mine worked at Norton and took me for a ride on one of the test mules.
It was incredibly smooth and performed well.
We had to cut our ride short as it dropped onto on cylinder or should that be rotor?
What was impressive is that it continued to ride well but with less power than before and was able to take two quite large lads back to base without any fuss.
On the odd occasion that my Bonneville tried the same trick it was a right pig, much slipping of clutch and complaining of motor.
Thanks for the link, Max. Interesting ad and a few more rotaries at the foot of the page.
Further to Pete's question apparently they built 142 of the F1 but of course there were also the Commander rotaries.
Further to Pete's question apparently they built 142 of the F1 but of course there were also the Commander rotaries.
