The term 'spherical starter' refers to two different types of starters used in engines. The first is an ATMO starter, which stands for Atmospheric Motor. This type of starter uses a combination of air and fuel to start the engine. The second type is a HEMI starter, which stands for Hemispherical Motor. This type of starter uses a combination of air and fuel to start the engine, but it also has a hemispherical combustion chamber that helps to increase the efficiency of the engine. Both types of starters are used in various types of engines, and they both help to ensure that the engine starts quickly and efficiently.