Sources and method

Engine Diagrams publishes firing orders and cylinder locations only when they are confirmed by at least two independent sources, one of them factory information wherever it exists. The 3D engines and diagrams are generated from the same data, so they cannot disagree with the tables.

What is checked

• Firing order: two or more sources give the same sequence.
• Cylinder numbering: two or more sources give the same bank and position for every cylinder.
• Placement in the vehicle: for each way the engine is fitted (front to back, or sideways), two or more sources agree on which side or end each bank is.

The site build refuses to publish an engine that fails any of these checks.

Sources used

• Factory service manuals and technical service bulletins from GM, Ford, Chrysler, Honda and Toyota. Most are read through Operation CHARM (charm.li), which reproduces factory service information for 1982-2013 models.
• Manufacturer performance-parts instruction sheets (Chevrolet Performance, Ford Performance, Mopar) and Ford owner's manuals.
• Independent references such as Engine-build.com and BackYardMechanic, used as the second source and as a cross-check.

Conventions

• Driver side and passenger side are for left-hand-drive vehicles.
• Left and right bank are seen from the flywheel end of the engine looking toward the front, as the service manuals use them.
• The 3D engines are schematic: they show where each cylinder is, not the exact shape of the engine.

Corrections

Each engine page lists its sources with the relevant quotation. If your engine differs from the page, check the sticker under the hood and the service information for your exact engine code.