This document discusses the assumptions and equations used in air-standard cycle analysis of internal combustion engines. It covers: - The assumptions of the ideal air-standard cycle, including constant specific heats, reversible processes, and no combustion. - The relevant thermodynamic equations for analyzing the Otto cycle of intake, compression, combustion, expansion, exhaust. - How real engine cycles differ from the ideal cycle assumptions due to varying composition and properties during combustion, finite combustion duration, valve overlap effects. - How to account for pump work from intake/exhaust pressures and residual exhaust gases in the clearance volume.