Engine break-in, Which is the best way? Options

[HectortheRican]

I'm trying to break in my motor as quickly as I can before Saturday or else I won't be able to take my car back to Albuquerque with me for a while.

The shop that rebuilt my motor and my mechanic all told me to do a slow break-in. You've all heard this one: Take it slow for 500 miles, change the oil/filter, take it slow for another 500, change the oil again and you're good to go. No highway, no higher than 55mph, and constant speeds are bad, mmmkay.

But I've been reading online and found a contradictory method that seems to have a lot of evidence against the manufacturer and mechanic recommended slow break in. It's called it's called the MotoMan method (here's the link: http://www.mototuneusa.com/break_in_secrets.htm). This one says that you should start off quick and hard in order to get the rings to seat properly and drive it normally for a little while and you're good to go. The biggest evidence against slow break-in that MotoMan has is that with the slow break-in, the cylinder walls are likely to glaze and the rings will never seat properly, thus causing oil burning and other problems down the road.

What are all of your opinions on this?

I've already started breaking in my motor and I'm 200 miles in. I didn't do it slowly, but I've been driving normally, except no hard acceleration and no constant speeds. I haven't gone on the highway and haven't gone faster than 45-50 mph.

[Syaoran]

I know somebody who's a professional race track driver who follows this method. His tuner does it on the dyno. Whenever they rebuild an engine for a new setup, they put the car on a flatbed and carry it over to the dyno a couple cities away (like an hour and a half drive or so; that car is an MR2 with a 3s-gte tuned by Predator Performance, Inc. in Puerto Rico. You can google that.)

They give it its first start and let it warm up to op. temp. at home to check for leaks and everything, but is never run on the street. Its first runs are done on a dyno using this method (3rd gear pulls with rests in between) and then the oil is changed. He uses AMSOIL break-in oil, because it has no detergents or additives, just pure 10w-40 if I'm not mistaken.

His build consists of 10:1 CR pistons with a fully build engine, 272 cams, titanium springs, retainers, HYDRA Nemesis II, I believe he's using a GT28-sized turbo running around 20~psi... and the engine is broken in boosted, of course.


I'd rather believe success stories than big companies who'd like you to bring the car in for work in the long run. I'm breaking in my engine this way when I build it down the road.


EDIT: The oil is SAE-30. Here's the link: http://www.amsoil.com/storefront/brk.aspx

I guess its motomans hypothesis versus the entire car industrys method. The point is that the cylinder walls are still rough. Why would you believe that running the rings harder, hotter and faster against a rough surface would be a better idea. Im not trying to be a dick Im just skeptical about anything posted as fact on the internet. Millions of engines have been built the normal way so why second guess that?

The idea behind this is that most of the time (in our case it is true) the rings are a softer metal than the cylinder walls, so seating them in softly will wear the rings and not the walls, causing excessive blow-by in the long run. Heat-cycling the engine as suggested by the MotoMan method heats up the cylinder walls, softening them up making it possible for the rings to wear INTO the walls, making a better seal.

This post has been edited by Syaoran: Aug 14, 2012 - 11:00 AM