Originally Posted by PencilGeek
We all agree that street and racing motors are different. I guess I was making two other points, and probably worded it poorly.
1. On the dyno, we broke in street and racing motors the same. Same methodology.
2. Whether street or racing, we considered the motor broken in when the rings were seated properly -- as witnessed when you stick an endoscope down the cylinder and take a look.
Of course other drive train components need to be broken in as well. That's why I chose my words very carefully by only discussing the break in of the motor.
I have broken in lots of motors on the dyno with very good results.I have found that most engines will seat the rings in the 1st half hour of running with some variation in load and I have never had an issue with oil usage or blowbye using a rapid breakin and that included 3 previous M-cars.My last Ducati came with very specific break in instructions just like my M3 did and because the dyno was broken,it had to be broken in on the road.
The dealer who is a racer,said to ignore the manual and just seat the rings as I always done and no prolonged full throttle(top speed runs) running for a while.The result has been no oil consumption and very little blowbye and thats with 20000 kms of street riding and over 60 track days.My friends who followed the long breakin as per the manual have had blowbye problems including piston & cylinder replacements.
I followed my method on the M3 and so far everything is working good so far!I am very anal about making sure that everything is totaly warmed up(oil temp) before going over 3000 rpm whether it is being "run in" or normal use.That is allways followed on all my vehicles and so far so good.