Some 90° V6 engines are built. They are usually based on V8 engines. It takes little work to change a V8 into a V6 engine. The problem is these engines are wider and have more vibration than a 60° V6. More modern 90° V6 engine designs avoid vibration problems by changing the crankshaft's design and firing timing. Balancing shafts are often used to remove the remaining vibration. 