Engines

DIESEL | How it Works - YouTube
diesel is long chain carbon; eating oil can be used in diesel engine if the injector can make them vaporize
diesel engine uses direct injection

PORT vs DIRECT vs DUAL INJECTION - a DETAILED comparison -EVERYTHING you need to know in 1 video - YouTube
What's The Best Fuel Injection? Carburetors vs Port vs Direct - YouTube Engineering Explained

New Mind
How Engines Are Becoming More Fuel Efficient - YouTube
The Story Of Fuel Injection - YouTube

Donut Media
FUEL INJECTORS - How They Work | SCIENCE GARAGE - YouTube
The Story Of Fuel Injection - YouTube
CARBURETORS | How They Work - YouTube
How Does A Carburetor Work? | Transparent Carburetor at 28,546 fps Slow Mo - Smarter Every Day 259 - YouTube
How Carburetors are Made (Basically Magic) - Holley Factory Tour | Smarter Every Day 261 - YouTube
Carburetors works because of Bernoulli's Principle; it is all mechanical and the simplest but cannot control the mixture ratio
Port injection is controlled electrically and mixes fuels before it reaches the cylinder (40-90 PSI); can clean the intake valve
Direct injection is also controlled electrically but resides within the cylinder and have much higher pressure (1.5-5K PSI)
IS THERE SUCH A THING AS BETTER GAS - How it Works | SCIENCE GARAGE - YouTube

These factors can be tuned:

Valve Timing (VVT)
Valve Lift (VVL)
Valve Duration (VVD)

Variable valve timing - Wikiwand electrical system
Car Tech 101: Variable valve timing explained - YouTube CNET
VTEC: How It Works | Science Garage - YouTube Donut Media
Engineering Explained
How VTEC Works - A Simple Explanation - YouTube
Variable Valve Lift vs Variable Valve Timing - VVL vs VVT - YouTube
The World's First CVVD Engine - Genius! - YouTube Honda's mechanical system
What Is Koenigsegg FreeValve? Camless Engine! - YouTube electronically controlled pneumatic actuators; tune each variable independently with faster responds

Otto cycle: standard four stroke
Atkinson cycle: shorter intake, longer expansion, delayed compression
smaller cylinder, more energy with less fuel
can be implemented with variable valve timing

Ignition

Diesel engines are more efficient as it is compressed until it ignites, no spark needed.

【龍 Sir 學堂 Ep01】Turbo 渦輪增壓是耗油還是省油的裝置？｜#REVchannel - YouTube
Compression ratio of engine = Clearance Volume + Swept Volume : Clearance Volume
Higher compression ratio means a more efficient engine

Ignition Systems - How they Work | SCIENCE GARAGE - YouTube
Is 'Entry Ignition' The Future Of Combustion Engines? - YouTube
The Spark Plug Story - YouTube New Mind

Spark Ignition: limited compression to reduce knock (ignition due to secondary compression after spark ignition)
Compression Ignition: higher compression ratio as only air is compressed
High Compression Combustion Ignition (HCCI)

PARALLEL TWIN: 360° vs 180° vs 270° - Ultra in-depth but EASY TO UNDERSTAND - ENGINE BALANCE - YouTube

Mazda Creates The Holy Grail Of Gasoline Engines - HCCI SkyActiv-X - YouTube
How Mazda Is Saving The Gasoline Engine - SkyActiv-X - YouTube
Mazda invented the HCCI (High Compression Combustion Ignition) engine that can does the same thing with gasoline.
SPCCI (Spark Controlled Combustion Ignition) compresses the gasoline-air mixture the the critical point and then induce explosion with pressure from the spark
Mazda's Secret New Engine Technology - SkyactivX | The New Car Show - YouTube
马自达 skyactiv-x 汽油压燃发动机工作原理讲解 How mazda skyactiv-x engine works? - YouTube

Rotary Engines

Rotary Engine | How It Works - YouTube
"Inside-out Wankel" rotary engine delivers 5X the power of a diesel

See through Rotary Engine in Slow Motion - (Wankel Engine) 4K - YouTube
The Differences Between Piston and Rotary Engines - YouTube
How Rotary Engines Dominated Motorsports - YouTube
The Challenge Of Designing A Wankel Rotary Engine - YouTube
Fixing the BIGGEST Problems of the Rotary Engine - YouTube

This 3D Printed Rotary Engine Is Genius - Mazda RX-7 - YouTube
Mazda Built A Hydrogen And Gasoline Powered Rotary Engine - YouTube
Mazda Brought Back The Rotary Engine! - YouTube

Mazda May Apply Skyactiv-X Technology to a Rotary Engine
The Holy Grail Of Rotary Engines - SkyActiv-X - YouTube

转子发动机什么原理？有多厉害？如何用勒洛三角形制作自行车？ - YouTube
转子发动机是什么原理？揭秘马自达 787B 禁赛背后的真实原因 - YouTube

Opposed Piston Engines

Opposed Piston Diesel Engines Are Crazy Efficient - YouTube

Opposed-Piston - Achates
Achates Power - Wikiwand

Hybrid Engine

mild hybrid
ISG: only use motor for starter and charge battery upon brake
full series hybrid
engine only generates power and not connected to drive train
full/mild parallel hybrid
both engine and motor are connected to drive train
Toyota, Lexus

【龍 Sir 學堂 Ep06】拆解豐田/凌志 Hybrid 省油耐用之謎｜#REVchannel - YouTube
【龍 Sir 教室 Ep27】混能系統工作原理新一代 Honda Jazz Hybrid 有何特別？（內附字幕）｜ TopGear HK 極速誌 topgearhk - YouTube

Electric and Hybrid Cars - YouTube

Superchargers/Turbochargers

Supercharger - Wikiwand
Turbocharger - Wikiwand
Turbocharged petrol engines - Wikiwand

Superchargers: What They Are, How They Work, and Why You Need One - YouTube
Turbochargers Explained | How Single, Twin-Scroll, VGT & Electric Turbocharger Works? - YouTube

The Science Of Boost - YouTube
Why Small Turbo Engines Are Not Efficient - YouTube

11 磅小老虎
涡轮的工作工作原理和特点，可能是最全最干的讲解教程 how turbo works? - YouTube
机械增压全解 / How do superchargers work - YouTube

Turbochargers and Superchargers - Forced Induction - YouTube Engineering Explained
TURBO HISTORY - Boost School #1 - YouTube
How does a turbocharger work? - YouTube
E-turbo. Is this an alternative to turbocharging? - YouTube

A supercharger is an air compressor that increases the pressure (or density) of air supplied to an internal combustion engine.
Turbochargers are also superchargers but run by a turbine (powered by the exhaust) instead of a belt linked to the engine.

Supercharger is mechanically driven by the engine to compress air, so it exerts load on the engine.
Turbo is also a form of supercharger driven by the engine's exhaust gases. This introduces lag for the power boost. Variable geometry turbo has differently-shaped turbine to reduce lag.

Turbo is a must for airplanes to maintain power at high altitude.
Jet engines has been turbo normalizing for ages to bring the air density back to sea level.

SUPERCHARGERS | How They Work - YouTube
Turbos: How They Work | Science Garage - YouTube

【龍 Sir 教室 Ep14】Turbo 點嚟㗎？Twin-scroll 又係乜？（內附字幕）｜ TopGear HK 極速誌 - YouTube
【龍 Sir 教室 Ep15】Turbo 引擎保養小貼士（內附字幕）｜ TopGear HK 極速誌 - YouTube

Turbochargers VS Superchargers - YouTube
Turbochargers vs Superchargers - Which Is Better? - YouTube

What's The Best Supercharger? Roots vs Centrifugal vs Twin-Screw vs Electric - YouTube