Triumph (TWN) BD250W
Video of my 1941 Triumph (Triumph Werke Nürberg) model BD250W (W=Wehrmacht). It is a 250 cc 'eins cylinder doppelkolben' (one cylinder with 2 pistons) 2 stroke engine. One piston controls the exhaust port, the other one the intake. The carburettor has a rotating valve for access of the mixture to the crank case. Lube oil is administered by a small lubricating oil pump which supplies 1 microliter oil every rev. The function of the 2 pistons results in asymmetric timing: the exhaust port opens ...
Tags: Triumph TWN Triumph Werke Nürnberg BD250W BD250 Doppelkolben 1941 German Triumph
