The combustion space is in the middle of the cylinder between the pistons.

燃烧的空间位于气缸中部，在两个活塞之间。

youdao

The internal combustion engine is a heat engine in which the burning of a fuel occurs in a confined space called a combustion chamber.

内燃机是一种热机，燃料在其被称为燃烧室的密封空间内燃烧。

youdao

Coal fire is a dynamic process caused by spontaneous combustion of the coal layer in various directions, accompanied by the sensible thermal field variation both in time and in space.

煤层自燃是一个动态变化的过程，随着自燃向不同方向扩大或缩小，其热场随着燃烧过程而发生空间变化。

youdao

Instead, two pistons face each other and the space between them serves as the combustion chamber.

FORBES: Engine Startup EcoMotors Signs Deal with Chinese Manufacturer

Without an internal combustion engine or transmission tunnel, the interior of Model S has more cargo space than any other sedan in its class and includes a second trunk under the hood.

ENGADGET: Tesla boosts Model S base price by $2,500 for new 2013 orders

The company also is developing four-wheel-drive technology that powers two wheels with an internal combustion engine and two with an electric motor, eliminating the need for a drive train that takes up floor space, Ho said.

NPR: China's Struggling Automakers Jump On SUV Boom