engine break in

[sext7366]

My guy told me to break in the cam above 1200rpm but try to keep it at 1500-2000,  but then after I tune it he told me to keep it running, and drive 75-100 miles on pure highway, anyone else heard of this...I have heard to baby it, and I have also heard not to be too nice on it, but does it really matter?  I know drag guys tend to break in a new engine at the track, so for a street engine seeing highway use, my shop guys technique does make sense, but what do you guys think.

[Chryco Psycho]

I break the cam in at 1800-2000 & do not flash the rpm up & start tuning while it is running by setting timing & adjusting mixture etc
I also take it easy on the engine for 400 miles or so , you can floor it just don`t let it pull past 4000-4500 until you have 400 on it

[tecmopar]

I do the same as Chryco on the cam break-in for about 15-20 minutes but depending on what rings you have that should be a little different. If they are standard cast iron rings then just don't drive it to hard for a few hundred but if they are any kind of moly ring you want to go out on a stretch of highway where you can put it in 2nd gear and run it from 2000 up to 4000 rpm, get completely off the throttle so the carb plates close and then shift to 3rd and do the same, bring it down, down shift to 2nd again and repeat this, up and down for about 20 miles or so.  This seats both the top side and the back side of the rings which is the most important thing you can do. This may seem like a pain but Again, be sure the throttle plates close when you get off of it to put back pressure on the rings with a load on it to get the rings seated completely, good luck.

[steves66]

I do the same as these guys during break-in and also after I get the car tuned to my liking I chop the throttle at about 500 rpm burst, so it won't be at one steady rpm for the duration of the break-in. After break-in I shut her down and changed the fluids before I started driving.