Comment by DebtDeflation

Honestly, just learn it like anything else. Understand the basic components of an internal combustion engine (block, crankshaft, rods, pistons, camshafts, cylinder heads, valves, intake and exhaust manifolds), the 4 cycles the engine goes through (intake, compression, power, and exhaust), how fuel delivery and ignition systems work. And then there are tons of resources on tuning and you can get the software for a laptop.