Complex sentence: Egli influenced other frame builders who went on to build their own'straight-tube' frames, including the Healey brothers whose Healey 1000/4 motorcycle comprised an uprated Ariel Square Four engine within an Egli-type frame.
Split into simpler sentences: Egli influenced other frame builders who went on to build their own "straight-tube" frames. These included the Healey brothers whose Healey 1000/4 motorcycle comprised an uprated Ariel Square Four engine within an Egli-type frame.