Ah, the quest for a smooth-running, efficient boxer engine.
Ever since I rebuilt the top end of my engine in 2005, I have been trying to understand how the magic of electrical sparks, fuel/air mixtures, valve adjustments and timing all come together to create this mythical purity in a four stroke engine.
Dealing with these engines are so much fun for me. There is an engineering component that I have absolutely no training on save for internet board conversations & factory manuals - although I love physics and wish I had studied it more. But there is a design component that I love because of the artful consistency between this motor and the car that it propells - all very purely related to the science of movement and beauty of well-crafted metals and glass.
The VW engine shares heritage with my 616 4-cylinder Porsche engine - namely the same engineer developed both. It was fun to run across a whole series of these factory training films - they are both a good overview of the issues and a reminder of what an elementary science class was like in the late 1970s.
...so there I'll be, in that dark, spider-filled garage working by headlamp: adjusting idle jets, accelerator pumps and distributor timing - checking it all twice - then going around Lakeview on test runs. On Saturday afternoon it was nearly there - and coming over the 35th street bridge it all started to harmonize around 65 mph...