The dealership will tell you do not be concerned with breaking in a reman. I still eased it in at changed the oil at 1000 miles.

 

my break in procedure--i do install my own engines

1- regular 10/40 dino oil first --prime the oil system before starting----start get the engine up to normal operating temps for about 20 minutes. turn it off and change the oil and filter. PUT A MAGNET SOMEWHERE IN THE OIL SYSTEM--on the filter--the oil pan drainage plug--it doesnt matter
2- after first oil change--drive the car normally varying loads and rpm ( no redlining but do go past 6 k)for 100 miles--change oil and filter again. still us dino oil. watch the engine and oil temps. Do not let the engine coolant get past 220F.Do not let the engine get to 210-215F on a regular basis. Do not let oil get pass 230F during this time.
3- drive for 1K miles 75% load, 75% rpm ( from redline)
4- Change the oil again--now use synthetic--you need a 40w oil or one that has the hths number of a 40 wgt such as redlines 5w/30.
5- dont let engine set and idle for "warm up" in the mornings--crank it-idle for just a few seconds--then drive in a normal manner.

This style of break in has given me the best results.
after 5K miles or so--you can redline it --full load it etc.
use this info if you think it can help.

 

Your saying all your rebuilds fail, ? They shouldn't fail for many many miles and yearsssss if is done right. Yearssss

 

He had mazda remans Chino.

 

O ok

 

Yep, that sounds pretty much like what I recommended as well.