Sad to say but: It was a very good decision to change my "D" mechanic !
After all things which went obviously wrong or wrong material was used (fuel lines, helicoil, ignition cables, dropping fuel on carburators, wrong jets) in the first phase have been corrected by the official ferrari dealer (including the detection of a slight crack on the fuel tank surface) the way was open to go to the guy (my new mechanic) who receives about all vintage Ferrari parts from the official dealers to adjust the ignition and carburators.
He worked on the car for 4 days and informed me every day about the findouts. We started by test driving it and he said that it feels like the carbs are too fat, the ignition not straight and the car has therefore not enough power IF there is nothing serious mechanically underway.
He went on to check the spark plugs and told me that on the right bench (6) only one spark plug presented itself correctly, on the left bench 3 were correct. He then fixed all distributor internals, changing many worn out parts, readjusting all timing and measurments after finding out that some parts have been loose or wrongly. After that, the engined runned quite well but not perfect. Now the carburators, which have been just adjusted by "the officials" were taken apart again, finding in 2 cases "short" type inside jets (instead of long one's) making the fuel falling into the carb and preventing low rpm torque. (I hope I explain this correctly, do not nail me on that please)
After fixing that, all 12 spark plugs had the correct picture.
I was in heaven when he called me today to say that he drove the Daytona and that the car is running perfectly now. He added that next to another one he services (of the about 20 Daytonas in total) he does not know of another one with that power. "Its a freight train from low rpm and please do not hesistate to run it up to 7-8'000 rpms ! These are racing engines from the time and build with purpose, you will be surprised about the difference when you pick it up". The car seems to be mechanically perfect otherwise as he checked the compression ratios before with high and consistent values.
After all, I'm very happy to hear that the engine runs on top of it's capacity only after some peripheral adjustments. I was almost starting to expect a engine rebuild if the adjustments would not show the needed results.
I'm very happy and wanted to share (no braging intended!). As Brian and Terry are so far away from here, I had to find another solution/mechanic
. Will report further when picking up and driving the car back personally !