You know...that's one o those "great mysteries"...really.I've not heard of any bike being "broken-in" by the book failing(the motor).But I have heard some stories about"you don't need to"...."ride it like you stole it"....and I sense SOME of those guys have experienced major engine damage..."within a few thousand kilometers"....(as the book says).HHHMMMMMmmmmmmm.That's the real thing....the only way to actually KNOW if the book break-in was faulty...is to do it like that...then have a blown engine or something a while later.Personally...I do believe those engineers are a shade smarter than I am when it comes to knowing their OWN product.

Some of it is just common sense, too. I mean really, when you got a bad-ass brand new bike sitting in front of you, you need someone to refresh your common sense a bit because all you want to do is dance!

You know...there may be some truth to breaking the motorcycle in "by the book"....frequent running and stopping heat cycling deals...you know...anyone do that?

Anyone who has put new rings in a motor will tell you this works. Basically, at first you don't want everything running smoothly so to speak. Those new rings are not making complete contact all the way around until they are properly worn in, only then will the engine make the most pressure and oil will stop blowing past the rings. This is why some builders will run a 'break-in' oil which can be as high tech as some cheap conventional to make sure the rings wear correctly. Otherwise, you will never be able to get them set with out rehoning.

For example. I put a big bore kit in my Suzy which involved new pistons/rings (obviously) and cylinder liners which were pressed into the block after it was hogged out some. Well being new to this sort of thing I had taken my carburetor bank apart to clean every little part and so when I put them together they were no longer adjusted and sync'ed. I figured I'd do that before riding the bike. I took me some time to adjust those carbs once I had the motor done all the while the motor is getting started and idled and shut off shortly there after. When I went to the machinist to tell him about the oil I was burning ( a quart every 100 miles!) he said I should have gotten on the bike and rode the piss out of it right away to break in those rings.

I'm pretty sure it's to late for a new bike owner to worry about this exact thing by the time they get the bike but it puts it all in perspective.
It's like a puppy. The first couple weeks of the dogs' life will dictate exactly what kind of dog it will mature to be by the way in which it is treated those important first weeks.

But that's all I got to say about that.

I have built enough motors to know you are right, Edge.

What have I built?

A Carerra engine with twin turbos, punched out to close to 6 liters for my 914-6. Got the engine from a front-ended Carerra and tore it all the way down, had the block checked, and purchased new cylinders and heads, a new crank, new cams, and closed-loop fuel injection unit. Did this on an Army base in the auto shop.

A 1962 Jaguar engine, 4.2 liters, and its transmission. Tore it down to the block, put in new pistons and ring of course, checked everything else, replaced crank and cam bearings. Did this on an Army base, in the auto shop.

A 383 Hemi (Plymouth) for my Cuda. Torn down to the block, new crank, new bearings everywhere, bored cylinders, new pistons and rings, had the head massaged. New intake manifold, new exhaust manifold, new cam. It dyno-ed at 640 horsepower on high test. Did this in the same Army auto shop.

Kawasaki Z1, down to the block, new crank, new bearings complete, new cylinders, pistons, cams, heads, carbs. (done for me for free, sponsored to drag race for a Kawasaki shop)

Kawasaki ZX11, down to the block, new crank, bearings, cylinders, pistons, cams, heads, close-loop fuel injection (I paid to have the work done)

I broke every one of those, and every new vehicle ever had, bike or car, running the range of rpms and gears for at least 2,000 miles (4k for bikes) so that the vehicle never spent more than a minute or so at the same rpm in the same gear.

Everyone one of those machines turned out to be extremely long lived, and performed at a high level. Even the machines I abused on the drag strip. I drag raced the Z1 wearing license plates but with rearsets and clip ons and a small gas tank and DOT legal slick in bracket racing, and other than eating the clutch on a regular basis, the engine was rock solid. I kept it on high octane pump, with no nitrous, all engine.

I'm sure others have done otherwise and had machines turn out just as good. I'm just old school.

* Last updated by: privateer on 5/4/2011 @ 9:14 AM *

I run a single stock fan, regular dex cool and 1 bottle of water wetter. Hasn't been above 2 bars yet this year.

Ran the same setup in the big motor. It would occasionally get to 4 bars on really hot days.

Slow, I doubt anyone else is running as cool as you, unless they are still having cool weather. Your results are abnormal.

Why do you think this is so ?

On 40-45c+ heat in the driest State on the driest Continent,South Aussie days my thermo comes on at lights and goes off as soon as I'm moving again with OEM Coolant, same as both of my Blackbirds did too.we avoid most Suburban roads & the City ,Plus the Country roads n Twisties are Heaps more fun anyway LOL

* Last updated by: bean07 on 5/24/2011 @ 1:03 AM *

"A Carerra engine with twin turbos, punched out to close to 6 liters for my 914-6. Got the engine from a front-ended Carerra and tore it all the way down, had the block checked, and purchased new cylinders and heads, a new crank, new cams, and closed-loop fuel injection unit. Did this on an Army base in the auto shop."

Not causing an argument, just trying to keep this thread accurate!
Ive been into Porsches for a very very long time and currently own 2 including a 911...I think you are a bit confused on the 6 liter part. There is no way to bore or stroke out a 911 engine even close to that...if its an air cooled motor no piston/jug combo is available much beyond 3.8 liter and with the newer water cooled ones nowhere near enough room to make it happen! Cylinders cant overlap each other lol! I could see maybe 4 liters but thats pushing it as well!
As for breaking in an engine, I agree with changing up rpm often but I disagree on babying it. Also if its a race engine (where the stock tune would not be correct) I would suggest breaking it in on a dyno while tuning to be sure its not too rich/lean and timing is right...then make some full power passes once the tune is good. I have a built 1.9 liter motor (cp pistons/pauter rods/sleeved/ etc) with a sc61 turbo on it pushing 520 whp at 25psi broke in this way that now has 40k miles on it and is still running great.

* Last updated by: markaria on 7/10/2011 @ 9:12 AM *