Typically, if I build a new motor requiring "break in" (new cam) we will do the normal 2,000 rpm once fired up until the motor gets to 190-200 degrees. We will typically try and do a test n tune at the track and make a few passes and if everything goes well, change the oil before the next outing. I have had one engine dyno'd. Mainly because it was my wife's Ford 351W and I had a very knowledgeable engine guy build it since I'm not up with all the tricks and what not to keep a ford engine together. We broke the cam in on the dyno and made 6 dyno pulls. Did a test n tune and than changed the oil after that outing as well. Our engines are fairly basic pump gas with flat tappet cams making 5-550hp, so nothing over the top and very mild compared to most other racers setups.