Its been a long time since iv been on here but i think this subject is intriguing.
As daft as it sounds an awful lot can be learn about cam overlaps and exhaust port scavenging in "Tuning the A Series Engine" by David Vizzard. That guy did great work on minis and becasue of their somewhat difficult inlet and exhaust port configurations, cam profiles (including scatter pattern cams) and exhaust pressure waves are covered in good detail.
As far as the backfires are concerned on F1 cars in particular during gear changes i was always led to believe this was due to the engine power being cut simply by missing the spark at the time of gear shift. In this case the throttle would be wide open on upshifts and blipped on downshifts, this unburnt mixture would then ignite on contact with the exhaust.
When i attended the British GP in 2005 i did notice that the Minardi and Jordans suffered from these gear change backfires far worse than most other teams as it was almost every shift, maybe this is something to do with packaging or reduced complexity in the electronics.
