Douglas 1930 “ T 6 ” 596 cc side valve flat twin frame # XF 2229 engine # EQ 2107
It is at the 1929 Olympia Show that the new S5 ( 500 cc ) and S6 ( 600 cc)models make their appearance.
Designed by Freddy Dixon, these are undoubtedly the most silent and flexible motorcycles available at this time.
The whole design concept is bristling with new ideas, even to the extent of following car design in certain aspects.
Who else can virtually guarantee a minimum of two years’ service without need for replacements?
These are the “Dixon Douglas” models, with which his name will forever be linked.
For the first time a dry sump lubrication system is employed, without recourse to any external pipes.
Very long valve guides are fitted to the cylinder barrels and the cylinder heads are detachable, above the valve seatings.
Very long tappet guides are also used and all the valve gear is completely enclosed behind finned tappet covers.
The induction system is cast-in with the timing cover to ensure the necessary warmth after a cold start. A B.T.H “pancake” dynamo, mounted immediately above the induction system, operates the lighting circuit.
The dynamo is driven by gearing from the crankshaft and is specially made for the Douglas range.
The 600 cc model has bore and stroke dimensions of 68×82 mm.
The T6 was the touring version of the S6 and differed only in minor aspects such as the footboards.
(source: Jeff Clew, “The best Twin”) .
At first impression this fine Douglas may not seem to be mother’s finest, but she is authentic and runs like clockwork.