Break-in for Re-built Motor?

Looks like you are not getting much of a response so I will throw out my 2 cents. At start up, follow typical camshaft break-in directions. That is, once it starts, get it up to over 1500rpms for 15 to 20 minutes. After that, shut it down and change the oil. Drive it normally after that following Ford's reccomendation of varying rpms if driving down the interstate. City driving obviously will vary the rpms for you. After about 1000 miles, change the oil again.....then drive her like you want to. I haven't had any problems this way. I run Mobil 1.
 
When I broke in my rebuilt motor in my 96 I changed the oil after the first 500 miles. Changed it again around 2k miles later, I will then be changing it again at the next 2.5k miles which is around 700 miles away. At this time I will be switching to a synthetic like royal purple. After every oil change I cut open my filter and inspected it. During the first 1k miles I varied rpms a lot, took it pretty easy on it but I was no way pu$$y footing it. I was told I did not have to break it in for so long but when you have gone through 3 motors in your car in matter of 7 months and just spent $6k on a brand new one you tend to be a little cautious.
 
these motors don't need a "break in" period like people think...put regular cheap 5w-30 in there and drive easy for 500 miles...change the oil, inspect the filter by cutting it in half and refill the engine with regular oil...drive it however you please at this point and after 2k miles change the oil again...you can switch to a synthetic after 2-3k miles
 
kah9911 said:
DO NOT use mobile 1 to brake in the engine. You will not get the rings to set properly! I started using mobile 1 after ~900 miles.

Good point.....I forgot about that. I also would like to add, that the camshaft breakin step I mentioned before may not apply to a rebuild by a shop or a factory rebuild. There may have been a "run-in" period by the people who put the engine together. :shrug: Probably a good idea to know what they do prior to delivery, or simply follow there reccomendation since they are giving you some warranty..
 
I say run it hard. Of the cars with fresh motors that I have driven hard, I have had the best performance...........not very scientific on my part but check this link out.

It's an article written by a cycle builder with 300+ engine rebuilds with out any problems. He even includes some "after" pics of pistons showing the difference between the factory type recommended method for break-in and his method.

Moto Tune USA dot com foward slash break-in-secrets

Hop
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I just got my 00 GT back with a new motor too. I took it out for a few good WOT runs, some engine braking, and 700 interstate miles with slowing down and accelerating alot with a few cool off periods in between. Seems to be running nice and strong... changed the oil at 770miles, dont have anything to cut the filter open with though.
 
when I got my GT I floored the hell out of it to break it in.. first 1000 miles I was pretty hard on it.. then I installed some 373 gears and ran a 13.8 at 100 MPH..