J.A.W. wrote:The Germans ran different ign' timings between plug sets ( & even comp' ratios per bank) on their V12s..
Not sure on the ignition timing for German IV-12s, but the compression ratio differentiation (on DBs - not sure on Jumos) was due to oil consumption. Jumos and DBs used fork and blade rods.
FWIW I thought that timing difference was used on such (DB) engines that had different banks at different meps due to an asymmetric effects in the induction system (from a cramped supercharger positioning ?)
regarding overboosting .....
the Munich/Manchester United crash in 1958 was somewhat bound up with boost control issues
a few years ago a TV drama/reconstruction showed the pilot pushing the power levers forward and the auto system opposing this by pushing the levers back against the pilot's efforts
authentic reconstruction or dramatic fiction ?
and a technical bit ....
if with a conventional 2 stroke we eg increase the B:S ratio with 10% more bore and a corresponding 21% reduced stroke
ie to enable about 10% mpre rpm and power
for a given port timing we have ports tending to 10% wider (ie diameter) but 21% squatter .... so smaller when we needed bigger
this was a limiting factor eg with GP 2 strokes