W & P made high speed petrol engines for many motor manufacturers but most of their large engines were for Dennis Brothers Limited who became their largest customer.
dˈʌbəljˌuː ænd pˈiː mˌeɪd hˈaɪ spˈiːd pˈɛtɹəl ˈɛndʒɪnz fɔːɹ mˈɛni mˈoʊɾɚ mˌænjuːfˈæktʃɚɹɚz bˌʌt mˈoʊst əv ðɛɹ lˈɑːɹdʒ ˈɛndʒɪnz wɜː fɔːɹ dˈɛnɪs bɹˈʌðɚz lˈɪmɪɾᵻd hˌuː bɪkˌeɪm ðɛɹ lˈɑːɹdʒɪst kˈʌstəmɚ.