I am in the process of rebuilding my ls keeping it stock, new rings, bearings, etc. There is alot of controversy over what this site suggests to do http://www.mototuneusa.com/break_in_secrets.htm. I have searched and searched, but all opinions are contradictive, and almost nobody has actually tried it to say if it actually works or not. Even though there isnt much/any hard evidence proving it, im leaning towards trying it. Has ANYONE had experience with this break-in procedure good or bad?? Please if you have leave your input. Also, the directions are a little vague, so if somebody can elaborate a little more on how exactly and what to do, that would help too.

 

I did a hard break in on my current build, 6 months later and it still has 210psi across the board, exactly the number it had after driving it around the block the first time. I drove it about 10 miles before I bolted the turbo on.

I followed the mototuneusa method you have mentioned and it worked great for me. It makes perfect sense to me too. Nothing needs "broken in" besides the rings, and the rings need pressure on them to seat well, so load them good.

The bearings should NEVER make metal to metal contact anyways, so why would they need broken in? Theoretically they never touch anything besides a thin layer of oil.

Put it in and drive it like you are going to drive it.

 

for break in, i usually take it out a good 50 miles or so with A LOT of engine braking which helps with seating the new rings. and if you're on a proper map, get on it all u want!

been good for quite a few motors so far. no problems since