breaking in rebuilt ka24e motor. Whats the proper way to do so?

[ssmikeyss]

When i finally get my motor together, what is the best way to break it in, as far as letting it idle, rpms, how many miles before i put a load on it, etc? I'm getting a few suggestions, but they seem a little contradicting. Most of my input is coming from guys who are used to rebuilding big blocks. I need a pro who is experienced with these little monsters! I searched the archives and can't find much either. Any suggestions from you guys would really help!

[JNM240]

Basically, what i did was start it for the first time, let it get up to operating temperature while looking for leaks and trying to make sure the small ammounts of smoke coming off the motor was from fingerprints and grease burning off, and not exhaust leaks. Once up to temp, turned her off, checked all the fluids once again. Started her back up, waited, set timing and idle, drove around the block. Then i just took it easy for a day or two. I changed my oil after the first 50 miles (i was using the cheapest oil and filter i could find), then again after 500 miles. After that 500 miles, i let her rip. Hope this helps.

[240ka24]

If I had a new cam and new bearings, I would first break in the cam then the piston rings and then the main/con bearings. If its just new rings and bearings, I would drive the car in 2nd and full throttle(no overrevvin!)and release..repeat maybe about 20 times and the rings should be done., the bearings I really dont care about but YOU prob should drive it(no overrevving!) for at least 500miles.

IF new cam, follow the manufac directions then do the rings and bearings.Thats just my way of breakin in motors. hope this helps.

[ssmikeyss]

Right on guys! Thanks for the info! It is much appreciated!

[240sxmech]

You have to be kidding me..come on guys really? That has got to be the most nonsense i have ever heard..

First thing is to pull plugs and turn over engine till oil pressure is made then reinstall plugs, make sure you have oil in the engine. Start the engine up and hold it at around 2 grand this seats your rings, about every 2 minutes rev it up to about 4 grand really quick two times and let it come back to 2 grand this breaks your cam in, if using old cam then dont have to do this step. Need to hold it at 2 grand for about 25 minutes but if it starts to heat up cut it off and let it cool down then continue with break-in. Have a buddy check for leaks while you are holding the rpms. After your break in set your timing and top off your fluids.This is the proper and only way to break a motor in. After your break in period you may drive it but dont put a load on it or rev it out for your first 500 miles and no constant speed driving for your first 500. After your 500 miles get the oil and filter changed.Whatever you do dont do what the others said in this post.

[ssmikeyss]

thanks for the input!