File under "Zen and the art of motorcycle maintenence."
Cheers
Looks like we have a winner in the organ donor derby. Highway speed on a bad road with those wheels? Yikes.
Somewhat unrelated, but cool. A Swiss company RinSpeed is making some interesting vehicles:
[External Link]
Don't be silly, Dara. That thing could never reach highway speeds.
Posted at 2008-01-31 11:30:13 [PermaLink]Dara: Too bad, Top Gear has beaten RinSpeed to the punch: [External Link]
Posted at 2008-01-31 12:35:54 [PermaLink]Damian,
I'm a sucker for specs and design info so I went a couple of links deeper into the story and found this:
[External Link]
The top speed is listed as 110 km/h. Probably goes 150 when Kim Jong Il is riding it.
According to the specs it has a 5-stroke engine. They exist, but I don't think I've ever seen one.
Reportedly North Koreans are being forced to buy them rather than the less expensive and more reliable Chinese motorcycles they're used to.
Bruce,
You've never seen a Prius?
Thanks to the energy capture of exhaust gases with the extra stroke its petrol engine gets a high efficiency for a combustion engine, about 35%.
It's called the Atkinson cycle. Mazda has also used it in the past as the Miller cycle, which is a revived variation of original. They seem to have a thing for exploratory engines but seem to have dropped it along with their Wankels. It gets high efficiency but loses high RPM power for it.
Geely makes at least one motor scooter with a single cylinder 5 stroke and there are quite a few of them in the Korean brochure I linked. It would seem the idea is catching on.
They're making a low powered engine that doesn't require complex rotation balancing or a lot of valves due to its one cylinder design. It can be cheap and lightweight. The main barrier to implementing the cycle is the complex piston motion required, with only one the problem is probably a lot easier to solve.
Isn't that really just 4 strokes with the backflow and compression occurring in the same stroke?
I thought that in a 5-stroke engine the 5th stroke is refrigeration.
Bruce,
Yeah, it's a cheat with the miller cycle as there are still four distinct strokes, but the compression stroke is broken up into two parts. But it is called a five stroke cycle, whereas it's actually a five phase cycle.
I guess it is possible that the Asian manufacturers are introducing a refrigeration stroke into their design, making it a "true" five stroke. With a single cylinder, it is considerably easier to pull off, but I'd guess that they're really just using a Miller cycle.