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| tom66:
--- Quote from: nctnico on May 31, 2023, 07:18:02 pm --- --- Quote from: RJHayward on May 31, 2023, 06:24:24 pm --- Now, if you care to unpack that opening statement; I'm trying to say, related to a newer, offset piston engine being covered by YouTube. --- End quote --- The engine in the Toyota Prius already uses an offset crankshaft (probably since the first model). And I doubt they are the only ones. Toyota recons it improves efficiency by 1 to 3 percent. --- End quote --- Is this related to the Atkinson cycle used in most/all Toyota hybrids? It is ideal for hybrids because the lower power output can be supplemented with an electric motor, giving more acceptable power outputs. |
| nctnico:
--- Quote from: tom66 on June 01, 2023, 04:02:53 pm --- --- Quote from: nctnico on May 31, 2023, 07:18:02 pm --- --- Quote from: RJHayward on May 31, 2023, 06:24:24 pm --- Now, if you care to unpack that opening statement; I'm trying to say, related to a newer, offset piston engine being covered by YouTube. --- End quote --- The engine in the Toyota Prius already uses an offset crankshaft (probably since the first model). And I doubt they are the only ones. Toyota recons it improves efficiency by 1 to 3 percent. --- End quote --- Is this related to the Atkinson cycle used in most/all Toyota hybrids? It is ideal for hybrids because the lower power output can be supplemented with an electric motor, giving more acceptable power outputs. --- End quote --- No. Afaik the offset camshaft is just an extra. Googling around shows this is very common practise for all kinds of engines. Maybe all engines have this as it is a simple trick to prevent wear that doesn't cost any extra. The Atkinson cycle has nothing to do with it. |
| Infraviolet:
Wankels, poor efficiency? I thought the whole point of the wankel rotary design was high efficiency, but that they were rarely used as they were a manufacturing tolerances and maintenance nightmare? |
| SiliconWizard:
--- Quote from: Infraviolet on June 01, 2023, 05:14:44 pm ---Wankels, poor efficiency? I thought the whole point of the wankel rotary design was high efficiency, but that they were rarely used as they were a manufacturing tolerances and maintenance nightmare? --- End quote --- No, the whole point was: a lot fewer moving parts, a lot smaller and lighter for a given horsepower, and much reduced vibrations. While it was possible to achieve a higher peak horsepower with a smaller chamber volume, it unfortunately never equated with a higher fuel efficiency - Wankel engines are quite hungry. Really the benefits are much reduced vibrations and lighter engines for a given horsepower. |
| coppice:
--- Quote from: Infraviolet on June 01, 2023, 05:14:44 pm ---Wankels, poor efficiency? I thought the whole point of the wankel rotary design was high efficiency, but that they were rarely used as they were a manufacturing tolerances and maintenance nightmare? --- End quote --- Wankels can achieve high efficiency under ideal conditions, but have been lousy when used in things like NSU and Mazda cars. Mazda seems to have brought back their Wankel engine as a range extender for an electric car with a modest sized battery, where it can run in perpetually ideal conditions (apart from warm up, of course). Used in this way it is a very compact and lightweight solution, that should last a long time, and is reasonably efficient. It should also be highly reliable, although that will come down to how well it has been implemented. |
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