I am surprised that the carb v12 has vac retard and no vac advance.
Apparently this is (any of/ all?) for some emissions reason, to give a faster warm up or to smoothen the idle.
There are lots of variations in the actual system depending on the market. Here in oz, no emissions control was mandated until 76, yet the earlier cars still had the retard system
This must mean that part throttle timing is not ideal (advance only centrifugal).
I’m interested in the idea of modifying one carb to give a ported vac (perhaps copying a range rover carb).
I note that there is a JLM520 vac canister that might give the best of both worlds - cruise advance and idle retard
any experience/ advice?