engine break in questions

[fr3ed0m]

so i finaly got my truck running ive put about 10 miles on the motor in the last 3 days so far it seems good but here is my question, what rpms should i bring the motor up to the highest this motor has ever revved not counting the cam break in is 2k rpms problem is i have no exhaust i just have long tube headers so its pretty loud right now, im getting my exhaust done today when i wake up so once its on and quieter should i be pushing it harder or to higher rpms? im scared to push it on open headers because i cant hear if the motor where to start knocking or anything with the sound echoing off every curb and wall in town, this is my first time breaking in a new motor so any advice would be awesome its a 383 stroker with a very mild cam if that means anything but i would assume its the same for most motors

[truckdude239]

after the 2k 20 min break in it should be fine just be easy on it for about 300 miles or so

[Monty]

i've always done it like this: warm it up and do the 'round the block dirve' a few times. change the oil. then warm it up again and then work it pretty hard. the theory is if you baby a new engine the cyllinders will glaze.

when we break in locomotive engines, we idle them just long enough to get the 10 and 30 min. bearing temps and top end inspection, then as soon as temps reach operating range, we go to full throttle/full load for 8 hours...

my two cents

[70cst]

I'm signed on...

I have heard many theories on this.

[pumpkin]

Once the cam is broke in,,,,,,,,,your done, go have fun. The misconception of breaking in an engine comes from new car advise of not going over a given speed and so on. This is because you are breaking in (so they say) everything that is new. My theory on this is the longer you drive it easy, the closer to get to the end of the warranty. I have built many engines, after the cam is broke in I go see how much power we have. The only time that anything goes wrong is when something wasn't done right in the first place. A nascar engine builder once wrote, break in the cam, put a brick on the gas pedal,, leave for 5 hours, if its still running when you cme back you did a proper job. With roller cam engines there is no break in. The big problem you will have now is finding oil with the proper amounts of zinc and such to make the cam survive. All regular gasoline and diesel oils that are currently available will wipe out your cam in vary few miles. All that metal that comes off the cam will go through the rest of the engine destroying all bearings and bearing surfaces.

[fastwillie 696969]

Originally Posted by pumpkin

Once the cam is broke in,,,,,,,,,your done, go have fun. The misconception of breaking in an engine comes from new car advise of not going over a given speed and so on. This is because you are breaking in (so they say) everything that is new. My theory on this is the longer you drive it easy, the closer to get to the end of the warranty. I have built many engines, after the cam is broke in I go see how much power we have. The only time that anything goes wrong is when something wasn't done right in the first place. A nascar engine builder once wrote, break in the cam, put a brick on the gas pedal,, leave for 5 hours, if its still running when you cme back you did a proper job. With roller cam engines there is no break in. The big problem you will have now is finding oil with the proper amounts of zinc and such to make the cam survive. All regular gasoline and diesel oils that are currently available will wipe out your cam in vary few miles. All that metal that comes off the cam will go through the rest of the engine destroying all bearings and bearing surfaces.

i say more in the main bearings than cam bearings