Many Crankshafts Are in a V12 Engine?

A V12 engine typically contains one crankshaft, regardless of its cylinder configuration. Here’s why this design dominates and the exceptions you might encounter:

1. The Standard Design: Single Crankshaft

V12 engines are built with 12 cylinders arranged in two banks of six, forming a V-shape. All pistons connect to a single shared crankshaft at the engine’s core. This setup ensures:

Simplicity: Coordinating 12 pistons through one crankshaft reduces mechanical complexity and weight.

Balance: The V12’s 60° or 120° bank angles naturally cancel vibrations without needing additional balancing shafts.

Power Delivery: A single crankshaft efficiently converts linear piston motion into rotational power for the transmission.

Real-world examples include classic V12s from Ferrari, Lamborghini, and modern luxury cars like the Rolls-Royce Phantom.

2. Exceptions: When Dual Crankshafts Exist

While rare, dual-crankshaft V12 engines have been explored in niche applications:

Experimental Prototypes: Some designs use two crankshafts to alter piston dynamics or combine engines. For example, early Lamborghini V12 prototypes explored a "split" design where two inline-6 banks shared separate crankshafts.

Custom Builds: Enthusiasts or racing teams might merge two inline-6 engines with synchronized crankshafts, but this requires complex gearboxes and sacrifices reliability.

However, these are not standard production configurations.

3. Why Not Two Crankshafts?

The single-crankshaft design persists due to critical advantages:

Cost and Weight: Adding a second crankshaft increases manufacturing costs and engine weight, reducing fuel efficiency.

Synchronization Challenges: Aligning two crankshafts to avoid destructive vibrations is extremely difficult.

Optimized Alternatives: Engineers prioritize enhancing single-crankshaft designs (e.g., forged steel materials, advanced balancing) over dual-shaft experiments.

Final Answer

99% of production V12 engines use one crankshaft. Dual-crankshaft designs are limited to experimental or custom projects, not mainstream vehicles. For automotive enthusiasts, the V12’s magic lies in its balance of power and simplicity—all driven by a single, masterfully engineered crankshaft.