Atkinson Cycle tagged posts

Yesterday we brought you the news that Toyota released some information for their new generation of high efficiency naturally aspirated engines.

After research we come out with some analysis and our viewpoint:

1. Most of the technologies are borrowed from previous higher level products (not necessarily within the Toyota Group only). For example the VVT-iE valve system, previously appear on the 1UR V8 engine, which is used on Lexus LS460 and IS-F.

2. The 1.3L is a 4-cylinder engine, while the 1.0L is 3-cylinder. Pay attention to the difference in their compression ratio. Why the 1.3L has 13.5:1 and the 1.0L only gets 11.5:1...

Today Toyota released some information regarding their new generation of naturally aspirated engines.

There are two engines are mentioned in the news. One is 1.3L and another 1.0L. Key points:

– Atkinson burning cycle (10% better fule economy)

– VVT-iE valve technology (previously only available on Lexus LS sedan)

– High compression ratio of 13.5:1 for 1.3L and 11.5:1 for 1.0L

– Stop-start technology

– Direct fuel injection is not required (but it can still come with DI)

– Speical design intake ports makes combustion more rapid

– Cooled EGR system to reduce emissions

– 1.3L engine thermal efficiency: 38%; 1.0L efficienty: 37%. Compared to old engines of 35%

– Modified pis...