Ok, my $02 -
1) You have to build up pressure in the cylinders so the rings are forced to the walls. The spring pressure of the rings themselves definitely won't do this. You need some full-throttle pulls where combustion is at it's highest pressure - this doesn't mean you have to go flat-out, you can do this in the first few gears as Sean suggested. You also don't have to go to red line. Normally peak torque output is somewhere near 2/3 of the rev range. You want to reach that peak torque with the throttle under full load several times over the first 50 miles. Peak torque is not a coincidence - it is where the engine reaches it's maximum volumetric effeciency - thus generating the maximum force on the crank and generates the most pressure to push/force those rings out against the cylinder walls.
2) I completely disagree with running it hard full-time. You need to generate "heat cycles" - building heat, then allowing a relaxed pace, build heat, then relax several times so the parts "wear in". Maximum heat full-time will cause maximum expansion of parts and if the tolerances are too tight, then you could expand before break-in to the point of siezure or at minimum - scoring. It depends on the tolerances you left in the ring gap - too tight and too hot - she is going to score or seize, too loose and it won't matter.
On a street engine, I like to build them to minimum tolerances so I can have long wear and durability. I also enjoy the break-in period because I'm making it mine. As long as you pull to max torque and load several time during break-in, you're going to seat those rings and not risk scoring or seizure.
Here is an example of a 900 Kawasaki I recently bought with 17,500 or so miles. It was not broke-in correctly. It's owner never opened the throttle in the first couple of thousand miles. He never let the engine get to full load and torque rpm - so, the rings never got pushed out to the walls while they were "sharp" and they became smooth/rounded (glazed)and never seated in the cylinders. You can still see the cross-hatch pattern. This engine had absolutely "0" zero wear, did not use oil, but the compression was only 125 - all because the rings and cylinder never consumated their marriage 32 years ago.
I also use only synthetic oils in every engine I own. Even my Snapper lawnmower has it. I won't go into that debate, but it all has to do with the flash-point temperatures conventional and synthetic oils turn to vapor and burn. Cylinder walls and piston bottoms constantly exceed the temps where oil turns to vapor/varnish.
Regards,
Gordon
