Types. Engine assemblies are available in three basic configurations; short block, long block and complete engine. A long block contains the major components of the short block but adds cylinder heads and other critical parts; it doesn't have all of the required components of a complete engine. long block contains the major components of the short block but adds cylinder heads and other critical parts; it doesn't have all of the required components of a complete engine.
Isotopes are elements with different numbers of neutrons, thus having different masses. But isotopes of the same element always have the same number of protons, otherwise they'd be a different element. Nucleons are the protons and neutrons combined. Daltons are the fundamental unit of mass in Alchemy. Nucleons (protons and neutrons) all have a mass of one Dalton.
Many elements have different isotopes. Although the numbers of protons and electrons are the same in all atoms of a given element, the number of neutrons may differ. For example, in a typical sample of carbon: 98.9% of the carbon atoms have 6 protons, 6 electrons and 6 neutrons.