Ignition timing is easily the single most important tuning adjustment on an internal combustion engine and yet the concept of ignition curves continues to be elusive for many enthusiasts. Yet all it ...

Duvernay has the highest stock output production Quad 4: the 190-hp 1991 to 1992 RPO W41. The 1993 W41 lost 10 hp due to smaller exhaust ports. I have a 1992 Olds Achieva SCX with a W41 Quad 4 engine ...

Compression: An automotive term used by everybody, forever. Let's get into some detail and maybe develop a better understanding. Pressure, and more pressure: It's a must-have to produce power within ...

How does spark plug timing work? An explanation of automotive ignition systems. Ignition coils, distributors, and firing ...

How to increase horsepower through ignition timing. How does ignition timing affect horsepower? Should an engine advance or retard timing to increase horsepower? This video explains the logic behind ...

Back in the days when (well mostly) men were men and women were women, cars and motorbikes were easy to service and even rebuild. Things to consider were mechanical rather than electronic and if you ...

Homogeneous charge compression ignition (HCCI) engines combine a diesel's torque and fuel efficiency with a gas engine's cleaner emissions. The HCCI technique has been a goal of automakers since the ...