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interesting break-in article. thoughts?


cOoTeR
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I think it's stupid. Beyond belief stupid. Run it hard so there is extra pressure against the rings before the roughness on the rings wears off is his claim. WTF, there is no extra pressure in the cylinder at higher rpm. It's X psi every stroke regardless of how many strokes per minute. Do rings need to seat, yes but it is a natural event that requires no extra effort. Just do what the manufacturer suggests which is next to nothing in most cases.

This dude it's just another dumbass that thinks he it's smarter than the engineers that designed the engine.

Edited by Tonik
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Did you hear about the conspiracy of motorcycle manufacturers to prematurely wear out engines & sell more bikes by advising easy break ins. A co-worker decided he was going to do a hard break in on his V-storm. Next thing I hear is that his engine mysteriously seized up. Luckily the dealer replaced it under warranty. I suppose that under very controlled conditions (ie dynomometer) a hard break in will work. I never had any problems with breaking in bikes per owners manual.

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This dude it's just another dumbass that things he it's smarter than the engineers that designed the engine.

And there you have it. You have the Asian kid telling you "this motor was built like this to do this and should be broken in like this" and then you have some random dude telling you "all engines need to be rode hard jus do 'er ike is 'ere. Aww hell hold my beer I'll do 'er for ya".

I'll go with the Asian kid. Or in my case the German kid.

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I've read that load, not rpm is bad for an engine break-in. That you should explore the entire rpm range, but under soft load, ie low gears and no hard acceleration. I don't have break in instructions for my Honda 850 project, but I will have over a grand in the motor. I will be breaking her in easy.

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I think it's stupid. Beyond belief stupid. Run it hard so there is extra pressure against the rings before the roughness on the rings wears off is his claim. WTF, there is no extra pressure in the cylinder at higher rpm. It's X psi every stroke regardless of how many strokes per minute.

There is a static and dynamic compression that can cause cylinders to have a higher compression ratio at higher RPM's. At low RPM (static) the most valve overlap happens causing pressures inside the cylinder to escape out of the open valves. As RPM's increase the amount of overlap decreases causing cylinder pressures to go up (dynamic). The more radical the cam the larger effect this will have on the dynamic compression ratio.

Spark knock typically doesn't occur at low idle, but when it revs high you can pull the data and see it is knocking due to higher RPM from higher compression and the computer retards timing to compensate.

So he does have some basic physics of an engine down, but he contradicts himself.

He makes a point about how a ring can't seal against high engine pressure then immediately gives us an explanation on how it will seal the high engine pressure if you rip it hard. The same few pounds of spring tension remain either way and the ring will form around the cylinder either way. And if his way magically doubles spring tension to seal pressure my rings will be scrapping the hell out of my bore causing premature wear of both ring and bore.

This is a fail. Factory break in and swap to synthetic after the first change has worked for me. I've used oil analysis to confirm it so I can sleep at night.

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I bought a new crate engine for my truck and it said to let it run till it reaches operating temp then let it cool down completely. then drive it up to about 50 mph and let it engine brake to about 20 mph 12 times. then the engine is fully broken in.

most engines will spin rod or main bearings. you want to break in the valvetrain, cam bearings, rod and main bearings. the piston rings are not the major concern.

Edited by serpentracer
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When I worked at a Honda motorcycle shop, we had to rebuild about every demo bike's engine. Sending it out to suddenly let rip on the local freeway, wasn't the right way to break in the engine. They would blow smoke. Rings failed to seat during break-in (or lack of).

Some race engines that you only need for a few hours, that can be an entirely different break-in. But even then, results will vary...

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I tend to agree with the "break-it-in-hard" mentality, with some limitations.

It's not the RPM that makes the gas pressure go up- it's the open throttle and more complete cylinder filling that does it.

I don't go full RPM on a new motor. I think that's just stupidity. Loads go WAY up with RPM.

I vary the RPM as much as possible, giving it full-throttle midrange pulls into the upper midrange, not lugging it and not revving the snot out of it. Then I let it coast down against the motor. I do this in different gears, never lugging it or revving it out. At 50-60 miles I change the oil. I ride it normally at that point, but stay out of the high RPM until 500-600 miles. I change the oil again. I increase the RPM some more. At 1000 miles I change the oil and ride it like I stole it.

This has worked for multiple bikes. None burn oil and all have motors that make good power and sound good.

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from what I can tell (seen on a lot of shows) your bike was put on a dyno before it left the factory. car companies and all do it now to "road test" them.

some car engines that I seen were basically ran before it was put into the car anyway.

I'm sure most engines are already broken in before you get it.

I heard the mechanics with my bike all the way in the showroom. I almost didn't take the bike as they were basically redlining it. the sales guy said yamaha tells them to do that. I've heard from a bunch of other people the place they bought their bike from did the same thing.

Edited by serpentracer
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