Flat-plane crank

The flat-plane crankshaft was used in the World War II Sherman Tank in the Ford GAA engine, an all-aluminium 32-valve DOHC 60-degree liquid-cooled V8.

However, the flat-plane design is no longer widely used in most mass production V engines as it is more prone to vibration and is inherently much louder than a crossplane crankshaft.

However, due to its simpler construction requiring less counterweight, it is inherently lighter with a higher rev limit.

[1] Flat-plane crankshafts are generally associated with European sports cars such as Ferrari and Lotus V8 engines, and cross-plane cranks with American manufacturers.

[4] The 2023 model year Chevrolet Corvette Z06 has the largest flat-plane V8 ever seen in production cars at 5.5 litres.

Computer generated image showing the major internal moving parts of a DOHC inline-four engine, including the flat-plane crankshaft
Front view of a V8 flat plane crankshaft with corresponding connecting rod positions