This insert has a smaller volume and a higher compression ratio than our standard VHM insert, which translates into higher torque at low and medium engine speeds. This improves acceleration and gives a greater sense of torque when exiting bends. However, bear in mind that this compromises top speed. The combustion chamber fits perfectly into the VHM cylinder head and is easy to replace. The last digits of the reference number are engraved on the insert for easy identification.