Flat Plane Vs Cross Plane Crankshaft

By Ryan Loveland

(Ford Mustang GT350 Flat-Plane crank)

V8 engines (8 cylinder engines aligned in a V-formation) are some of the biggest engines on the road today. Producing deep exhaust notes and tons of horsepower they are great ingredient for a sports car. But what is the difference between a flat plane vs a cross plane crankshaft? “Early V8 engines were all flat-plane cranks, because that's a simpler, more straightforward design. A flat-plane crank V8 is really like a pair of mated I-4s, and there's some issues with them, the biggest issue being balance and vibration issues, specifically secondary balance and vibration issues.” (Torchinsky). To correct the problems with the flat plane, a cross plane crankshaft was made. A cross plane crankshaft keeps the cylinders firing in both banks which keeps things balanced and gives off that v8 sound everyone loves. Although these cross plane cranks are much larger and heavier than a standard flat plane, which doesn’t allow the engine to rev as high as a flat plane crank engine. Flat plane works better for racing allowing some engines to rev up to 8000 RPM, which is why some new sports cars like the Ford Mustang GT350 uses one of these flat plane crankshaft engines. If you want to learn more about it and watch a video, click here.

Torchinsky, Jason. "What Is A Flat-Plane Crank And Why Is It So Loud? An Explainer." Jalopnik.
CarTech, 17 Nov. 2014. Web. 11 Oct. 2015.