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Australian Team Working On Engines Without Piston Rings
JabrTheHut writes "An Australian team is seeking funding for bringing an interesting idea to market: cylinder engines without piston rings. The idea is to use small grooves that create a pressure wave that acts as a seal for the piston, eliminating the piston ring and the associated friction. Engines would then run cooler, could be more energy efficient, and might even burn fuel more efficiently, at least according to the article. Mind you, they haven't even built a working prototype yet. If it works I'd love to fit this into an older car."
But we already have an engine that doesn't use piston rings. And it's not like this idea hasn't been tried before either on reciprocating piston engines, usually with a whole series of problems. Mostly compression issues.
Om, nomnomnom...
That has been solved for a while. Oil jet to to bottom of the piston. They have been doing that for a long time in racing and motorcycle engines.
See my blog http://ilovecookes.blogspot.com/ for light hearted technical information.
'Knock' is detonation. The words you are looking for are 'piston slap'.
John McAfee 'It was like that time I hired that Bangkok prostitute; to do my taxes, while I fucked my accountant'
Looking for funding without a physical proof of concept?
How much would it cost to create a prototype? Get a used lawnmower engine, find a piston from a slightly larger used lawnmower engine (up to here you spent about $50), then turn some grooves in there and see how it purrs.
What are we talking about? a couple hundred bucks?
It would cost way less to try this in real life than all the computer simulations. Something smells fishy.
I believe this is not true. When I lived in New Zealand I noticed that the octane ratings were higher than in the USA, but after researching this, discovered that the difference is mostly accounted for in a difference in the way that octane is measured. In New Zealand (and probably Australia, and probably Europe), the rating uses just the "research octane", i.e. that measured in a lab somewhere; but in the USA, the rating is an average of the "research octane" and the "measured octane", the measured octane producing a lower number, that when averaged with the research octane, means that the same fuel is rated at a lower octane rating than it would be in New Zealand.
'Knock' is detonation. The words you are looking for are 'piston slap'.
No, 'piston slap' is something different. It's what we do to people who quibble about terminology. ;)
I don't care if it's 90,000 hectares. That lake was not my doing.
The parent poster is correct. See examples of conversion between various fuel ratings and look at the "regular" gasoline entry. Basically, take the US rating and add 4 to get the Australian/New Zealand equivalent.
What are the advantages of ceramic engines?
Heat resistance would allow the engine to run hotter, allowing more efficiency per the Carnot cycle. Difficulties include preventing your fuel from combusting early, how to lubricate at temperatures that will cause normal oils to smoke, etc...
There's some weirdness in that ceramics done right can be lighter than steel, and due to their hardness and not expanding/contracting as much tolerances can be tighter, perhaps even reducing the need for lubricants.
I don't read AC A human right