Department of Engine

Power and Efficiency

Variable-valve timing (VVT)

Basic Principles

VVT's benefit to fuel consumption and emission

Different systems:

1. Cam-changing VVT - e.g. Honda 3-stage VTEC, Nissan VVL

2. Cam-phasing VVT - e.g. BMW Vanos / Double Vanos, Toyota VVT-i

3. Cam-changing + Cam-phasing VVT -  e.g. Toyota VVTL-i, Porsche Variocam Plus, Honda i-VTEC, Audi Valvelift, Mercedes Camtronic, GM iVLC

4. Rover's unique VVC

5. Continuous variable valve lift (CVVL) - e.g. BMW Valvetronic, Nissan VVEL, Toyota Valvematic

6. Electrohydraulic valve control - e.g. Fiat Multiair

Intake and exhaust

Tuned intake manifold

Variable intake manifold

Variable length intake manifold

3-stage variable length intake manifold

Continuous variable length intake manifold - e.g. BMW DIVA

Variable trumpets - e.g. Ferrari F12tdf

Resonance intake manifold - e.g. Porsche VarioRam

Tuned exhaust & variable back-pressure exhaust

Multi-valve engines


Advantages and Disadvantages

Solutions - e.g. Toyota T-VIS

Number of Valves - 3, 4, 5 or more

Forced induction

Ram Air Intake


Roots type supercharger

Eaton TVS supercharger

Lysholm (screw type) supercharger

Centrifugal supercharger



Light pressure turbo

Variable turbine geometry (VTG)

Variable-volume turbine by Koenigsegg


Parallel Twin-turbo

Sequential Twin-turbo

2-Stage Variable Twin-turbo

Twin-scroll turbo

Cross-bank turbocharging - BMW twin-turbo V8 as example

Turbo + Supercharger - e.g. Volkswagen Twincharger


Throttleless engine - BMW Valvetronic


Twin-spark plug


Variable Compression - Saab SVCNissan VC-T

Atkinson cycle engine

Miller cycle engine

High compression engine - Mazda Skyactiv-G

Low compression diesel engine - Mazda Skyactiv-D

Fuel injection


Gasoline Direct Injection

Stratified charge direct injection - e.g. Mitsubishi GDI

Direct injection by EGR - e.g. Renault IDE

Stoichiometric Direct Injection - e.g. Alfa Romeo JTS

Spray-guided direct injection - e.g. Mercedes CGI

Dual-mode injection (direct + port) - e.g. Toyota D-4S

Diesel: common-rail direct injection

Emission control

Pollutants and Emission Standards

Catalytic converter

Diesel Particulate Filter (DPF)

Selective Catalytic Reduction (SCR)

Exhaust Gas Recirculation

Alternative Fuel

Electric cars



Efficiency and GHG emission

Hybrid cars

Mechanical Hybrid - Volvo Flywheel KERS (2011)

Mild Hybrid - Toyota Crown (2002)Honda Insight (1999)Auto stop-start with brake energy regeneration

Full Hybrid - Toyota Prius (1997)

Plug-in Hybrid (PHEV) - Chevrolet Volt (2010)

Hybrid Transmission - Planetary CVT

Hydrogen cars

Hydrogen Engine - BMW Hydrogen 7 (2006)

Hydrogen Fuel Cell - Mercedes NECAR 4 (1999)Toyota Mirai (2015)

How green is hydrogen?

Engine Packaging

Volkswagen VR6 and W-engines

First generation VR6

Second generation, 24-valve VR6

W12 engine

W16 engine

W8 engine

W18 engine

Advanced materials

Aluminum head and block

Plastic or magnesium intake manifolds

Aluminum pistons and cylinder liners (including Nikasil and FRM)

Titanium connecting rods

Forged components

Engine Smoothness

Introduction and basic theory

Inline 2-cylinder engines

Inline 3-cylinder engines

Inline 4-cylinder engines (versus boxer-4)

Inline 5-cylinder engines

Inline 6-cylinder engines

V6 engines

V8 engines - flat-plane and cross-plane crank

V10 engines

V12 engines

All horizontally opposed (boxer) engines

Volkswagen VR6, W12 and W16

Volkswagen W8

Copyright© 1997-2017 by Mark Wan @ AutoZine