(A) inner sleeve
(B) outer sleeve
(C) link controlling inner sleeve
(D) Link controlling outer sleeve
(F) Slots for exhaust
(G) exhaust port
(H) slots for intake
(I) intake port
(K) seperate cylinder head
(J) wide 'junk' rings sealing intake and exhaust slots
(W) half speed crankshaft controlling sleeves
(X) lugs for control links
(Y)Ignition distributor (note twin spark plugs)