engine longevity

Still waiting to pick up my engine after having it rebuilt. It is being bored .20 over but that is the only internal upgrade. I do not know what brand name of kit was purchased (I'm embarassed about that one) but I was told ...factory specs...blah blah...(fill in the sales pitch here).

Question: How long should a rebuild last if it is run hard, not stupid, but more than driven on Sundays? I always change the oil after 3k sometimes less. I was told 50k and I find that a little disturbing. Is a rebuild going to last as long as say a new factory engine would?

Thanks

Not sure how many miles the rebuild will last; it depends on how tight the tolerances of the machining were and how well a job the machine shop did. Was it rebuilt by a small garage with a good rep or a service dealer?

As far as break-in procedures makes ure you follow specs to the T, not doing that of course will shorten engine life. Some others might help me out here but I am pretty sure break-in should be done on natural or blend oil (not full synthetic) for xxx number of miles so the rings will seat properly. Again I do not know the figures but that is what I heard.

But if you have a freshly built engine I would swap over to full synthetic (worth the 4-5 bucks a quart) post-break-in time. I have used Vavoline Syntec on my previous car and it was great. I have heard others on here swear by Mobile-1's synthetic as well, but I ahve never tried it.

For further reading on Motor Oil as well as other fluids:
http://www.vfaq.com/mods/fluids.html

A stroker may only last about 35k miles at high HP. For a regular rebuild, there is no reason it shouldnt last well over 100k mile if it was done properly.

As for hte break in, dont be afraid to build some boost right from the start. It will put presure on the rings and help them seat. I couldnt do this with my Ross/Eagle motor because of boost control issues, and the rings didnt seat for over 5k miles ;) You dont want to take it too easy on the motor, that wont help anywthing. The most important thing, is oil changes. Change it after you first start it up and let it run for 15-20 mins looking for leaks etc. Then change it at 100 miles. Then at 500, and 1000 miles. Then you can start the usual 3k mile intervals. The break in is a bit of a machining process. Lots of metal shavings are developed as the parts wear to each other. Use only Mitsu or Pure 1 filters too. Just trust me on that one. Good luck.

Does anyone make or use a "break in" oil. I know in aviation they use mineral oil for the initial break in.

I jsut use some cheap walmart brand oil, since its getting tossed after a couple hundred miles. I dont think there is such a thing for cars.