Break in?




#1
OK guys...here's the deal. I've raced sleds for 20 years. I've always broke them in the way I'm gonna ride 'em. I've got 200 rounds on the '02 Busa and I'm about ready to say to hell with it and let it rip. Suggestions or recommendations?
 

Narcissus

Hayabusa Immortal
Moderator
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#5
From personal experience, observation and actual testing, breaking-in an engine the way the factory wants you to do it is the wrong way to break it in. The engine always ends up with too much ring blow-by and less power than one that was put on a dyno and run from the start.

The bottom line is that the manufacturer wants the average end-user to baby the engine and be afraid of doing anything 'rash', like ever going over 5K rpm. That's fine if you don't race or build and tune engines and you probably will never notice the missing 5-10 HP. If you have any doubts on the break-in procedures for the real-world , find some reputable performance shops and tuners and ask them. Or better yet, just open up an engine that was done 'by the book' and one done in the first 50 miles.

Don't take my word for it, though. With so many people that swear 'by-the-book', you really have see the effects of different procedures on engines with your own eyes to separate the myths from reality.
 

MET

The Watcher
Registered
#6
If you are talking miles you can get real high up and still be in the break in. If you can try to break in at least the first 600 miles. Like you siad you break in to how you ride, just dont' crack and hold.
 
#7
hey ninja...no....its 200 miles not 1/4 mile drags...that comes later! As a side note, my best buddy just bought a ZX-12. ( no accounting for taste huh???? ) He had it on the dyno with only 25 miles on it
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!! I cringed listening to it hit the rev limiter with so few a miles on it....but he's an aircraft mechanic bytrade and wasn't too concerned about it. Since then he's had numerous dyno runs .....like around 15 so far and he has about 250 miles on the bike. He's laughing at me for being so cautious with my new toy after watching me beat the hell out of my sleds. BTW...the ZX was a 2000 bought new and he's putting out 158 - 160 BHP. Any of you guys from MN???
 

MET

The Watcher
Registered
#8
Your close, you do not want to baby it. Narcissus

Had some real sound reasoning, I think that you just do not want to hit the limiter until you get some miles to make sure everything is running well.
 
#9
yeah...I agree...no rev limiter but I've had it with the "keep below 8000 RPM thing. I know that when I'm breaking in a race sled, it ALWAYS pulls higher horsepower when its ridden hard...seems to set the rings better.
 
#10
I recall reading a web site not very long ago (and I thought I got the link from this very board) about engine break-in.

The author's philosophy is that the cylinder walls have a certain amount of cross-hatching in them to rub the rings and seat them.  Once that cross-hatching is worn away, the seating process ceases, and if you've babied the motor, then you've basically wasted that cylinder wall cross-hatching.

This sounds logical, but goes against common practice.  There seems to be this mysterious black art as to what is the best practice.  

I would add that I have a new Honda Accord, and the dealer and the owner's manual are very specific about *not* using the cruise control for the first several hundred miles.  The way it was explained to me is sort of hokey, but they said "Using your foot on the accelerator instead of the cruise creates a certain amount of 'pulsating' that helps the engine break in."  To me, that means on and off the gas is a good thing.  We know this produces "positive" and "negative" pressure inside the cylinders, and would also seem to agree with what I read on the above-mentioned web site.

That being said, I don't personally know what is best.  It would be great if there were an experienced mechanic on the board who would chime in.  
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Narcissus

Hayabusa Immortal
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#11
I need to find the link to the procedures, but basically, if you can run it on the dyno, you start out one run to ~5K, let it cool, another at a higher rpm, let it cool and keep doing it, four or five levels altogether if I remember correctly. Change the oil and filter, run it and you're done. After ~5K miles two engines apart, one done like above and another done by the manual, the first had clean pistons, rings and valves while the other had a lot of blow-by on the cylinders.

You can do the same on the street, warm the engine completely, ride it for a couple miles, bring it home and cool it down, repeat at higher RPMs. The heating/cooling process is the most important part. For some people, the 500-1000 miles that the manual suggests can span a month or even a season. That just isn't enough to temper the seals.
 
#15
I did baby mine at the start partially because the last bike i rode was a baby and this felt like a beast. When i took it to be dynoed the numbers were fine and the mechanic said "there no way to screw up a busa motor run in or not, they are rock solid."
 
#16
I think another important thing to avoid is high cylinder pressure... it's not the RPM's that get you, it's high pressure before things have had an opportunity to seat properly.  As long as the load is light (i.e. 1st gear, 2nd gear) I don't think that any harm will come by zinging the engine up (WOT can wait for a while though).  WOT in 6th gear at 40mph probably isn't a good idea at all.....

The heating and cooling cycles are important too.... pistons have a tendency to get all funky shaped when they are heated for the first few times.  The heat cycles condition the aluminum to its (hopefully) permanent shape (that should resemble the cylinder walls.  I saw pictures of some pistons that a guy put in his oven (to speed up the break in process on a SBC drag engine).  The pistons were distorted so bad they would never even fit in the cyclinder bores.....  oops!
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Here's another theory I have heard about.... I just don't know how much to believe... I have heard that babying the motor also creates a small lip where the rings don't travel as far up/down and when you finally let the big dog eat, the piston,rings actually travel further (we're talking a very small distance here) and sudden ring wear can occur.  I have even heard failure mentioned, but I really don't belive that.  It would have to be one hell of a lip.  Just some bench theory......
 
#17
Ok when I first got my Busa I started doing things by the book...taking it easy. After about 200 miles I stoped by the dealer and he asked me if I cranked on it yet. My other bike was a built V Max so they knew I could handle a bike with a set of balls. I told them no not yet, and he said to me what the hell is wrong? I told him I was doing the bike by the book. Ya want to hear the response I got from him? It when something like this... ( Go out and crank it! I want to hear about some serious SPEED!) He told me the going for 500 miles then uping the rpms was not for the BIKE!!! It was to get the rider accustom to the bike so people did not just go out get in over their heads and get killed! So if you have skill and some serious time on sport bikes go at your own pace BUT CRANK IT!!!!!!!!!! IT can take it I am at 10,000 miles now and my 2000 is an animal it was built to go! Just use your head about where ya let the fur fly!!! :whip:
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rgd808

Registered
#18
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I have 130 miles on an '02 I broke it in for 34 miles the last 96 miles have all been put on at the drag strip. I shift at 10800 RPM and have hit the rev limiter a few times.

I believe all new bikes come with warranties so break it in however you like.
 

Big O

Physicist Genii
Donating Member
Registered
#19
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 I babied my 93 GSXR for the first 600 miles and then ripped it for the next 73k until I sold it for my '02 Busa.  Never had a problem.  I've had the same mechanic and he said if you want the same mileage out of your Busa, break it in the same way. As far as the lip in the cylinder theory, I can't believe that there's that much play in the engine that the piston will go higher up the cylinder when you finally do crack the throttle wide open. I'll have to call my mechanic and get some answers.
 
#20
I'm also into aviation, and if there's ANY type of engine that would be considered high-performance in a critical-use position, it's aircraft engines.  The following is text that I've pasted from the Lycoming Aircraft Engine web page.  Read on...

>>>A new, rebuilt, or overhauled engine should receive the same start, warm-up, and preflight checks as any other engine. There are some aircraft owners and pilots who would prefer to use low power settings for cruise during the break-in period. This is not recommended. A good break-in requires that the piston rings expand sufficiently to seat with the cylinder walls during the engine break-in period. This seating of the ring with the cylinder wall will only occur when pressures inside the cylinder are great enough to cause expansion of the piston rings. Pressures in the cylinder only become great enough for a good break-in when power settings above 65% are used.

Full power for takeoff and climb during the break-in period is not harmful; it is beneficial, although engine temperatures should be monitored closely to insure that overheating does not occur. Cruise power settings above 65%, and preferably in the 70% to 75% of rated power range should be used to achieve a good engine break-in.<<<

You can read the whole text here if you like:  http://www.lycoming.textron.com/support/publications/engine_breakin.html

Not sure if that muddies the waters or clears them up, but I'm inclined to believe the aviation guys know what they're doing when it comes to engines.
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