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.
Atomic number and mass number. The atomic number of an atom is the number of protons it contains. All the atoms of a particular element have the same atomic number (number of protons). The atoms of different elements have different numbers of protons. For example, all oxygen atoms have 8 protons and all sodium atoms have 11 protons. The mass number of an atom is the total number of protons and neutrons it contains. The mass number of an atom is never smaller than the atomic number. It can be the same, but is usually bigger.