Tch, where's a :suckteeth: icon when you need one ...?
nothing is Triumph unless it was made at Meriden.
Did you mean to say Coventry? Those Meriden bikes were Turner/Page Ariels with Triumph on the tank
Uh-uh, while the singles
made at Triumph's Coventry works were designed by Val Page for the original 'Bettmann Triumph' company, and the 6/1 650 twin was a joint Page/Turner design for the same company, Turner dropped the 6/1 as soon as he was put in overall charge of 'Sangster Triumph' (Triumph Engineering Co.) and none of the singles was produced after that works was destroyed in the 14th/15th November 1940 Coventry blitz.
The only Triumph design to survive - because Triumph employees were able to collect the copies of drawings at outside suppliers - was Turner's Speed Twin/Tiger 100. And, while that was influenced by the Ariel Square Four, that too was a Turner-only design. The other well-known Speed Twin influence is the top end of the Riley Nine car engine; again, nothing to do with Val Page.
Meriden was built to replace Triumph's Coventry works, and demolished after the Co-op finally collapsed. So no motorcycle engine except Turner's Speed Twin/Tiger 100 and its direct descendants was ever built there?
Norton twins were the same, just Ariel man Val Page moved them on from those old singles
Val Page never worked for Norton. Leaving 'Bettmann Triumph' when that company ceased motorcycle production, he moved to BSA, taking charge of Ariel when the Sangster family sold it to BSA in 1944. Ironically, he ended up working for
Turner when the latter moved to BSA when the Sangster family sold Triumph to the BSA Group in 1951. BSA put Turner in charge of the whole Automotive Division, which then included the BSA motorcycles and cars, Triumph, Ariel, Sunbeam, Daimler cars, Carbodies (a coachbuilder most famous for making the London 'black taxi' from after WW2 'til only a few years ago) and several other vehicle-related companies.
Otoh, the first successful Norton twin engine was designed by Bert Hopwood, who would later take over from Turner in charge of BSA's (now smaller) Automotive Division when Turner retired in 1964.