Complex sentence: Turbocompound was used on on a few airplane engines during and after WW2 such as Napier Nomad and the Wright R-3350 Turbo compound versions of the Napier Deltic and Allison V-1710, were constructed but neither exited the prototype stage.
Split into simpler sentences: Turbocompound was used on on a few airplane engines during and after WW2 such as Napier Nomad and the Wright R-3350. Turbo-compound versions of the Napier Deltic and Allison V-1710, were constructed but neither exited the prototype stage.