Soooo many engines!
Sorting out info on the various Elliott (Adelaide) and Waratah (Sydney) bikes from the mid 1920s - mostly the 147/148cc models in the mid-late 1920s - has left me with many questions!
Both Elliott and Waratah used the little Villiers in Sun "miniature" cucyel parts (the extremely light set, with no rail under the tank) from the beginning of 1923 for Elliott and mid-1924 for Waratah. When they stopped is another matter - maybe 1928-29.
The weird thing is that the engines could be Mk VI-C (H prefix), Mk VII-C (L) or Mk VIII-C (W). We know about when they started (1922 for VI-C, 1923 for VII-C, 1924 for VIII-C), and we know that the VIII-C ran on through the 1930s, but what of the VI-C and VII-C?
I've seen an Elliott that looks pretty original with an engine number H24xxx (very large number for a VI-C) with "1924" stamped after it. It looks like this engine was maybe built in 1924, or if not built into a bike in 1924, by which time the VII-C had come and gone and the VIII-C was available.
I wonder did Elliott buy "old style" VI-C engines in 1924, or were they just left-overs of a 1922 batch?
Ditto for VIII-C engines with high numbers like L10xxx, built into bikes that seem to be 1925 or later.
I guess we'll never know for sure, but I'm pretty sure that dating a bike to 1922-3 because it has a VI-C, or 1923-4 because it has a VII-C is a bad idea! Looks like Australian manufacturers (at least) were using these engines in their bikes well after the VIII-C was available.
Cheers
Leon