Having the short block replaced, how to break it in?

[nicad2000]

I've just been notified that I'm eligible for a short block replacement under my 2003's factory warranty. Tried to talk my way into the long block but no go - they seem pretty inflexible about that sort of thing. Anyway, once I have the repair done, I'm wondering how to go about breaking the engine in. I've heard numerous different points of view on this and really want to take all possible steps to reduce my chances for oil consumption issues this time around. Has anyone had experience in this particular situation?

[szh]

Search for my posts on the topic.

Basically, don't baby the engine, and do lots of early oil and filter changes.

Z

[annab]

Sorry to say had mine replaced a couple years ago and it still smokes and now has an oil leak. It also has developed the "Gas tank isn't empty issue". I am going to sell mine, too many issues! Sad because I love the look, comfort and style!

[ken in az]

There are alot of theories out there on engine break in. I agree with what szhosain says but adding a little to it.

Keep the revs down, below 4K rpm but drive it hard right up to 4K rpm meaning don't be afraid to full throttle it right up to 4K rpm.

This keep rotational/inertial forces low but also allows for complete cylinder fill and will maximize the cylinder pressures to help seat the rings early.

most say to used DINO (non synthetic) oil for the first 3K mi. first oil/filter change at 500mi and again at 1500mi then switch to synthetic at 3K mi and start driving the piss out of it. another change at 6K mi and then you should be set to use synthetic at whatever extended oil change interval you desire - obviously within reason.

Ultimately it is up to you and I have no liability for any engine damaged incurred as a result of following my instructions

Search the web, there are probably hundreds of different techniques for engine break in.

[GJEMD]

I would suggest a 3 hr trip at sustained 3000 rpm

[szh]

I would suggest a 3 hr trip at sustained 3000 rpm

That sets the piston travel to a lower setting ... when deburring the machining of the walls during the initial break-in.

Much better to get the piston traveling just a bit (admittedly tiny amounts, but it makes the difference) past the normal maximum range.

So, the occasional high rpm (acceleration, not sustained) is useful and advisable.

Z

[ken in az]

I would suggest a 3 hr trip at sustained 3000 rpm

I actually think that almost everyone agrees that is and example of what NOT to do, but what do I know??

[GJEMD]

The conventional notions about break in are relative to cast iron and steel.The critical items on this engine are Aluminum, Titanium, and most important the Molybdenum cylinder lining. This changes everything. Sustained intermediate rpms at optimal operating temp. are what set this engine up for minimal oil consumption. The fact is break in, other than early abusive driving, has had little to nothing to do with oil consumption in the VK. This engine will ALWAYS consume some oil above 5500 rpm. Z you can't possibly imply that some how the piston travels in a different manner at differing rpms. An internal combustion engine is a very static in terms of motion and inertia, just a little physics.
Modified by GJEMD at 6:07 AM 3/13/2009

[ken in az]

Actually yes, the engine will behave differently at different rpms. The system is not static as everyone thinks. If you have the idea that the piston moves exactlt the same at 600rpm then it does at 7000rpm then you are completely mistaken.

The same rules apply to all metallurgical structures. Take a look at an aircraft wing durring flight - it is not fixed, more like it is flopping in the wind flexing attributing to the forces at hand. Also look at skyskrapers, they sway in the wind. Why do they flex? If they didn't, they'd break. Same thing is happening to the moving parts in an engine. even though the tolerances are much tighter and the movement isn't percievable to the eye, is is still flexing and behaving differently.

Just a little pysics for you - http://www.steel.org/AM/Templa...23463

[GJEMD]

Actually yes, the engine will behave differently at different rpms. The system is not static as everyone thinks. If you have the idea that the piston moves exactlt the same at 600rpm then it does at 7000rpm then you are completely mistaken.

The same rules apply to all metallurgical structures. Take a look at an aircraft wing durring flight - it is not fixed, more like it is flopping in the wind flexing attributing to the forces at hand. Also look at skyskrapers, they sway in the wind. Why do they flex? If they didn't, they'd break. Same thing is happening to the moving parts in an engine. even though the tolerances are much tighter and the movement isn't percievable to the eye, is is still flexing and behaving differently.

Just a little pysics for you - http://www.steel.org/AM/Templa...23463

Your wing comparison may apply at 7000 rpm, where the connecting rod is beyond factory specs and may stretch a bit or bend. But by the way we are talking about engine breakin and 7000 rpm is not relevent to the discussion and in fact would surely set you up a new engine for oil consumption. Break in is mostly moot with computer machined engines with molybdenum coated cylinders. The top end with titanium valveswith harden seats is like wise mostly moot. The rings are very well the weak link in these engines and if the case no system is stronger than its weakest link. The VK within operating ranges specified by the factory is static with little to no inertia. That would include the heads with 4 valves/cylinder, very little movement and virtually no valve train inertia.