New Motor Break In Procedure.

Brutusturbov6

Banned
Joined
Oct 19, 2007
Warning.
This is a very controversial topic but here goes..

I wrote "Break-In 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 lets get started...

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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.

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What's The Best Way To Break-In A New Engine ??
The Short Answer: Run it Hard !

Why ??
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 !!

An additional factor that you may not have realized, is that the person at the dealership who set up your bike probably blasted your brand new bike pretty hard on the "test run". So, without realizing it, that adrenaline crazed set - up mechanic actually did you a huge favor !!

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Here's How To Do It:

on the street, or off road (Motocross or Snowmobile.)

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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.

Realistically, you won't be able to do full throttle runs even in 2nd gear on most bikes without exceeding 65 mph / 104 kph. 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 (besides police) 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 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.

On the Racetrack:
Warm the engine up completely:
Do one easy lap to warm up your tires. Pit, turn off the bike & check for leaks or
any safety problems. Take a normal 15 minute practice session
and check the water temperature occasionally. The racetrack is the perfect environment to break in an engine !! The combination of acceleration and deceleration is just the ticket for sealing the rings.
Go For It !!


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Yeah - But ...
the owner's manual says to break it in easy ...

Notice that this technique isn't "beating" on the engine, but rather taking a purposeful, methodical approach to sealing the rings. The logic to this method is sound. However, some will have a hard time with this approach, since it seems to "go against the grain".

The argument for an easy break-in is usually: "that's what the manual says" ....

Or more specifically: "there are tight parts in the engine and you might do damage or even seize it if you run it hard."

Consider this:
Due to the vastly improved metal casting and machining technologies which are now used, tight parts in new engines are not normal. A manufacturing mistake causing a tight clearance is an extremely rare occurrence these days. But, if there is something wrong with the engine clearances from the factory, no amount of gentle running will fix the problem.

The real reason ???
So why do all the owner's manuals say to take it easy for the first
thousand miles ???

This is a good question ...


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Q: What is the most common cause of engine problems ???
A: Failure to:
Warm the engine up completely before running it hard !!!

Q: What is the second most common cause of engine problems ???
A: An easy break in !!!

Because, when the rings don't seal well, the blow-by gasses contaminate the oil with acids and other harmful combustion by-products !!

Ironically, an "easy break in" is not at all what it seems. By trying to "protect" the engine, the exact opposite happens, as leaky rings continue to contaminate your engine oil for the rest of the life of your engine !!


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What about running it in the garage ???

Maybe you have a new snowmobile and it's not quite winter yet, or a new bike and it's snowing...

The temptation to fire up a new vehicle in the garage just to "hear"
the new engine run can be very strong.

This is the worst thing for a new engine, in fact, my advice is:
don't even start it up until you're ready to warm it up for the first ride.

The reason is that brand-new rings don't seat all the way around the 360 degrees of their circumference. The gas pressure from hard acceleration forces the rings to contact the cylinder around their entire circumference, which is the only way the rings can properly wear into the exact shape of the cylinder to seal the combustion pressure.

Now, imagine if the engine is run in the garage. There is no load on the engine, so the rings are just going up and down "along for the ride". Only a small portion of their surface is actually contacting the cylinder wall. The ring area that does contact the cylinder wears down the roughness of the honing pattern on the cylinder walls. Once the roughness of the cylinder is gone, the rings stop wearing into the cylinder. If this happens before the entire ring has worn into the cylinder and sealed, you will have a slow engine no matter how hard it gets ridden after that point.

The difference between what happens in an engine running in the garage, versus one being ridden is a hard concept to put into written words, so if I may use the sounds that we all can relate to: it's the difference between "zing-zing-zing" and "bwaaaaaaaaaAAAAAA"

During "zing-zing-zing" the rings don't get loaded for more than a split second, whereas during "bwaaaaaAAAAAA", the engine is in 100% ring sealing mode and you are on your way to a nice running long lasting trouble free, smoking free performing engine :).
 
Thats generally what I have always been told. On the monster trucks we rarely test the engines before putting them into a truck... and the only time we get to get on it is SHOW TIME! I have never been able to keep my foot out of it in any new car...

I have a buddy that talks about the "good ol' tuneup days" and how his secret other than basic maintenance was taking people's cars out and running the piss out of them... everyone always was so pleased with how their cars ran when they got them back...
 
break in time

The new motor i just put in. cranked it up, let it run with no water for about 10 to 15 min then shut it off. checked everything good. pulled it out of garage put water in it, and drove it to the track wich is only 10 to 15 min away. Raised the hood and checked things again an then made a full 1/8 mile pass, it ran 7.20 at 18# of boost. seem to work for me so far. new times in sig now.
 
I remember back when I was in highschool working at a cycle shop and saw em break in the sleds I about shart. They lift the tails up start it get em warm and hold that biotch at wot slam the brakes and do it over and over.

Tech told me that was the best way to break em in. So I believe it. Shoot thats how my dad used to break in his harleys, wot on the street.
 
My last 2 motors were built and went straight to the track. No issues what so ever.
 
I just put this method it use on my new Talon's motor and after 15k miles it had less than 3% ring leakdown and all the cylinders are within 2psi!!!
 
Are you saying after a cam breakin that the cyl walls are already too smooth for the rings to fully seat? I always do some sprited driving on a fresh. motor,but not for extended intervals.
 
Did you ever wonder why you always hear about one car being a "good runner"? If you take 2 identical cars & race them, many times they will be really close but other times you'll get one that kicks the others ars! ( I worked at a Chevy Dealership as a tech for 18 years & PDI'd many new cars.) Same with the auto mags, they will come up with a time that sounds way out of the ballpark when compared to other mags. I always felt that break in was part of the reason. I know that sometimes an engine is put together & all the rods, pistons etc are uncommonly close in weight just by luck, making the car run better than most. I'm sure the the opposite is also true but I also feel driving the car as described during "break in" helps seal the rings as best as possible & the car become the "good runner" . Figure there has to be a reason why 2 exact cars will finish 1st & 2nd.
 
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