*Breaking-in newly rebuilt engines*everyone!!(Controversial)

[parkcityboyx]

I have done ALOT of research all over the web on how to break-in new/rebuilt engines, and answers are ALL across the board.

here's one quote from a site:

"The first few hundred miles of a new engine's life have a major impact on how strongly that engine will perform, how much oil it will consume and how long it will last. The main purpose of break-in is to seat the compression rings to the cylinder walls. We are talking about the physical mating of the engine's piston rings to it's corresponding cylinder wall. That is, we want to physically wear the new piston rings into the cylinder wall until a compatible seal between the two is achieved." ......

"Proper engine break in will produce an engine that achieves maximum power output with the least amount of oil consumption due to the fact that the piston rings have seated properly to the cylinder wall. When the piston rings are broken in or seated, they do not allow combustion gases to escape the combustion chamber past the piston rings into the crankcase section of the engine. This lack of "blow-by" keeps your engine running cleaner and cooler by preventing hot combustion gases and by-products from entering the crankcase section of the engine. Excessive "blow-by" will cause the crankcase section of the engine to become pressurized and contaminated with combustion gases, which in turn will force normal oil vapors out of the engine's breather, causing the engine to consume excessive amounts of oil." ....

.... it continues at http://www.ntnoa.org/enginebreakin.htm

obviously this is important to do correctly. and i have read way to many things that are completely controversial and opposing eachother. some articles say you HAVE to use the owners manual. others say that the owners manual is crap and you need to immediately break-in your engine hard right away with high RPM's and hard driving. and of course theres in-between stuff, and more extremes both ways.

SO, i wanted to go to the place where i have people i can trust! here! i want to here from everyone! i think this is a big thing that really can help us subie owners, that are doing rebuild work, get the maximum power out of our engines.

so if ALL and ANYONE that has rebuilt there engines(or not) on this site could pitch in and help not only me but everyone on here, i think that would be great.
how to....?
all experiences, all ideas, all recommendations, all info.......

[lozanoa11]

Well my experience and teachings has always been:
On first start up hold it at 1500-2000 rpm for atleast 15mins strait. The shut of and adjust the valves. Start back up and drive it normaly but not having it stay at the same rpm for too long. So no highway driving. No beating on it also. But some light city driving is best to introduce the engine to all loads and speeds. Change the oil at 100 miles then at 1500. After that you could probaly beat on it safely.
I have also heard to drive it hard first thing but i do not like that idea. If i saw some facts showing that was better then i would belive it but i would be worried about damaging cylinder linings when it is fresh.

Sorry kinda ramble there but you get the idea.

[parkcityboyx]

ya thats good.. i hope that more people come on and give some insight from there experiences.

[anothernord]

After my new shortblock was installed, the techs at my local Subaru shop told me to stay under 3000 rpm no matter what for the first 500 miles, then go in for an oil change before driving normally.

[Huffer]

Normal rules are to first oil change at 1000miles, stay with conventional oil until you hit 4000+miles then you can switch to a synthetic.

[Bookem]

Well my experience and teachings has always been:
On first start up hold it at 1500-2000 rpm for atleast 15mins strait. The shut of and adjust the valves. Start back up and drive it normaly but not having it stay at the same rpm for too long. So no highway driving. No beating on it also. But some light city driving is best to introduce the engine to all loads and speeds. Change the oil at 100 miles then at 1500. After that you could probaly beat on it safely.
I have also heard to drive it hard first thing but i do not like that idea. If i saw some facts showing that was better then i would belive it but i would be worried about damaging cylinder linings when it is fresh.

Sorry kinda ramble there but you get the idea.

This but with what Huffer said about the oil. The fine metal particles help with the break in, 1000 miles is good. Beating on it is considered flooring it or above 4k rpms, don't do that.

[lozanoa11]

Also i have heard use diesel oil. But i think that is just for cam in block flat tappet lifters but it may also apply to ohc engines.

[parkcityboyx]

alright this is good, i think i got a good idea of what im going to do. anyone else?? i want to get everyones ideas

[ScaryFatKidGT]

yeah iv just heard don't rev over 3-4 grand for the first 1000 miles and change your oil often. Like twice berfor 3000 miles than after that you can do what ever you want

[aekOne]

i'm halfway through a run at the moment. The rev limiter is set to 4000rpm and boost to 7psi for the first 1000km.

[4n70n1n0]

Wht I always heard was no driving above 3000 rpms for 1000 miles
Change oil
Baby it for another 1000 miles, nothing above 3000 rpms
Change oil
all set for abuse after that

[Soul Shinobi]

Engine Break In - NASIOC Wiki (http://wiki.nasioc.com/wiki/Break-in_engine)

In short, putting the engine under load after it's gently fully warmed up (I'd say about twice the time it takes the temperature needle to reach the normal operating range, you want to be sure all parts are good and warm) seats the piston rings to the cylinder walls the best. After one or two WOT blasts baby the car for a few miles before shutting down to cool any hot spots. After shutting it off let it cool completely before your next drive. As another user said, introduce the engine to varied loads and speeds. The connecting rods stretch at high RPM, so to wear the complete length of the cylinder wall I took mine up to redline at WOT two or three times in the first 500 miles. Yes there is a very real, but very small, risk of doing damage, but this is how you get a thorough break in.

I have very powerful rare earth (neodymium) magnets on my oil filter (from an old computer hard drive) and the end of my drain plug (from here (http://www.dealextreme.com/products.dx/category.1105~search.magnet)) to capture metal bits too small to be filtered. I changed my oil after 500 miles, and will again soon (1,500 miles later).

I do have a question, however, when can I start using synthetic oil? (EDIT: Huff covered that, 4,000+ miles) You don't want to break in with synthetic because it keeps the piston rings from seating to the cylinder walls (it's just too damn slippery, you have to understand break-in is controlled wear).