Acquired some more Scott/Jowett PAB bits (as advertised in SEM) over the weekend, so I heaved out my collection of parts from various sources including 'Matt The Sawyer' and Kim, to see how I was getting on towards a complete engine.
I have commented before that this engine uses a very un Scott like symmetrically domed piston with some sort of Schnurle derived scavenge system. Looking again at the porting, I noted that as well as the usual paired transfers aimed tangentially away from the exhaust, there was a third, steeply angled port immediately opposite the exhaust. This arrangement is usually attributed to MZ (the inheritors of DKW's legendary expertise in the field) who introduced it in 1957, yet here it was on a British engine designed in the late 1930's! Another example of a British lead thrown away?