[VicYouel]

Since 1979 I have acquired two 600 and one 500 model 9 engines plus a complete model 9 bike and a load of extra bits at autojumbles.  I have been doing yet more forensic analysis of my collection engine parts to try and figure out what is correct having got some bits muddled over the years!

(a) The early 1932 model 9's and the 600 model 9A used the same cylinder head (part no 6588B becoming 6588D for the 9) according to the June 1932 and March 1935 parts lists. The subsequent 9B and 9C heads became part number 8099 in 1933 according to the parts supplement and continued to 1935.  I have attached photos of two of my cylinder heads and you will note they have different bevels at the barrel interface. One on the right measures 80 mm and the other 88mm to the edge of the bevel so it is safe to assume one is for a 9  and the other for a 9B or 9C.  Now I am wondering what versions I have fitted to my two other assembled Beams?? Not a rhetorical question....I know I will have to disassemble them! Now the reason I am posting this missive:

(b) I have attached pictures of various  barrels from my stock:

(b1) Of my four 500 barrels (one on an assembled bike) one has a casting embossment of 500 and another with 500 plus the additional marking RCO casting logo. The other two have no markings. All have flanges at the crankcase end and three have three  fins cut away to clear the studs at the bottom whilst the RCO one has four fins cut away. Would appreciate confirmation as to what year they changed from 3 to 4 fins cut away.

(b2)  Of my five 600 barrels all are embossed 600 three have no flange at the crankcase end whilst two do have a flange. One of the latter is shorter and the same height as a 500 barrel (see later question). None of them have any fins cut away for the studs unlike the 500 ones. Was the flange included only on earlier 600's?

(c) In early 1932 the 9 and 9A used the same engine plates as earlier 1931 models but by 1933 the engine plates were changed and the effect was to lower the engine in the frame (needs a different chaincase etc).  The lowering of the engine made it easier to fit barrels and heads etc with slightly improved access to magneto stud nuts.

(d) For many years after having acquired that shorter 600 barrel which carries the label Model 9A part number 9258  I had jumped to the conclusion that 1933 engine plates were changed to accommodate the subsequent longer 600 barrels. However I think I may be wrong!!!! Referring to available parts lists, part numbers in the 9000 series did not commence until list no 16 dated March 1935.

Can anybody shed any light on whether early model 1932 9A's used the same length barrel as the 500 model 9?

Vic