I was reading an article.It looked it interesting and i thought to share it with you people.Here it is
This is a very controversial topic !!
I wrote "Break-In(Running) Secrets" after successfully applying this method
to approximately 300 new engines, all without any problems whatsoever.
Links to this article now appear on hundreds of motorsports discussion forums from all over the world. The reason is that over time, large numbers of people have done a direct comparison between my method and the owner's manual method, and the news of their success is spreading rapidly.
The results are always the same... a dramatic increase in power at all RPMs. In addition, many professional mechanics have disassembled engines that have used this method, to find that the condition of the engine is much better than when the owner's manual break-in method has been used.
The thing that makes this page so controversial is that there have been many other break-in articles
written in the past which will contradict what has been written here.
Several factors make the older information on break-in obsolete.
The biggest factor is that engine manufacturers now use a much finer honing pattern in the cylinders than they once did. This in turn changes the break-in requirements, because as you're about to learn, the window of opportunity for achieving an exceptional ring seal is much smaller with
newer engines than it was with the older "rough honed" engines.
In addition, there is a lot less heat build up in the cylinders from ring friction
due to the finer honing pattern used in modern engines.
The other factors that have changed are the vastly improved metal casting and machining
technologies which are now used. This means that the "wearing in" of the new parts
involves significantly less friction and actual wear than it did in the distant past.
With that in mind ...
Welcome to one of the most controversial motorsports pages on the internet !!
How To Break In Your Engine For
More Power & Less Wear !
One of the most critical parts of the engine building process is the break in !!
No matter how well an engine is assembled, it's final power output is all up to you !!
Although the examples shown here are motorcycle engines,
these principles apply to all 4 stroke engines:
Street or Race Motorcycles, Cars, Snowmobiles, Airplanes & yes ...
even Lawn Mowers !!
( regardless of brand, cooling type, or number of cylinders. )
These same break in techniques apply to both steel cylinders and Nikasil, as well as the ceramic
composite cylinders that Yamaha uses in it's motorcycles and snowmobiles.
What's The Best Way To Break-In A New Engine ??
The Short Answer: Run it Hard !
Nowadays, the piston ring seal is really what the break in process is all about. Contrary to popular belief, piston rings don't seal the combustion pressure by spring tension. Ring tension is necessary only to "scrape" the oil to prevent it from entering the combustion chamber.
If you think about it, the ring exerts maybe 5-10 lbs of spring tension against the cylinder wall ...
How can such a small amount of spring tension seal against thousands of
PSI (Pounds Per Square Inch) of combustion pressure ??
Of course it can't.
How Do Rings Seal Against Tremendous Combustion Pressure ??
From the actual gas pressure itself !! It passes over the top of the ring, and gets behind it to force it outward against the cylinder wall. The problem is that new rings are far from perfect and they must be worn in quite a bit in order to completely seal all the way around the bore. If the gas pressure is strong enough during the engine's first miles of operation (open that throttle !!!), then the entire ring will wear into
the cylinder surface, to seal the combustion pressure as well as possible.
The Problem With "Easy Break In" ...
The honed crosshatch pattern in the cylinder bore acts like a file to allow the rings to wear. The rings quickly wear down the "peaks" of this roughness, regardless of how hard the engine is run.
There's a very small window of opportunity to get the rings to seal really well ... the first 20 miles !!
If the rings aren't forced against the walls soon enough, they'll use up the roughness before they fully seat. Once that happens there is no solution but to re hone the cylinders, install new rings and start over again.
Fortunately, most new sportbike owners can't resist the urge to "open it up" once or twice,
which is why more engines don't have this problem !!
Here's How To Do It:
There are 3 ways you can break in an engine:
1) on a dyno
2) on the street, or off road
3) on the racetrack
(There are details given on three of these,I will be pasting the details of second one)
On the Street:
Warm the engine up completely:
Because of the wind resistance, you don't need to use higher gears like you would on a dyno machine. The main thing is to load the engine by opening the throttle hard in 2nd, 3rd and 4th gear.
The best method is to alternate between short bursts of hard acceleration and deceleration. You don't have to go over 65 mph / 104 kph to properly load the rings.Also, make sure that you're not being followed by another bike or car when you decelerate, most drivers won't expect that you'll suddenly slow down, and we don't want
anyone to get hit from behind !!
The biggest problem with breaking your engine in on the street is if you ride the bike on the freeway (too little throttle = not enough pressure on the rings) or if you get stuck in slow city traffic. For the first 200 miles or so, get out into the country place where you can vary the speed more
and run it through the gears !
Be Safe On The Street !
Watch your speed ! When you're not used to the handling of a new vehicle, you should accelerate only on the straightaways, then slow down extra early for the turns. Remember that both hard acceleration and hard engine braking (deceleration) are equally important during the break in process.
Article Source:Break In Secrets--How To Break In New Motorcycle and Car Engines For More Power