"breaking In" New Engine

[coltonb]

With the new engine in and running like new (thanks all for your help, especially steviej) i followed up with the dealer to see how i should break in the engine. (eg: oil change after 1,000 mi? no high speeds? no long distances?)

they had only one suggestion, "do no under any circumstances use cruise control for the next 5,000 miles" as they report that the engine must not be run at a consistent speed for even relatively short periods of time.

this won't be a problem for me to do, but the question is: why?

any thoughts?

[SKperformance]

never heard of that

except to give more variance to mesh all parts for milage

[jbarhorst2]

The fear is that if you run at the same speed for a period of time you can unevenly seat the piston rings against the cylinder walls. If you are constantly changing speeds (and therefore the load on the engine) then you will evenly "break in" the pistons, rings, and cylinders. The piston is pushing on different sides of the cylinder wall at different loads is the theory behind this.

I'm sure it goes back to the old days, rather than today's new tight tolerance engines. Was your mechanic of the older generation?

Tom

[coltonb]

The fear is that if you run at the same speed for a period of time you can unevenly seat the piston rings against the cylinder walls.  If you are constantly changing speeds (and therefore the load on the engine) then you will evenly "break in" the pistons, rings, and cylinders.  The piston is pushing on different sides of the cylinder wall at different loads is the theory behind this.

I'm sure it goes back to the old days, rather than today's new tight tolerance engines.  Was your mechanic of the older generation?

Tom

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don't know - phone conversation only. This was at the dealer though so I'd expect they'd be "up to date."

[Unlisted]

the no cruise control rule is for the Variable Valve Timing. It gives the computer false info about your driving habits .

[coltonb]

the no cruise control rule is for the Variable Valve Timing. It gives the computer false info about your driving habits  .

←

which raises the question: what info does the computer store about my driving habits? I've been deliberately dribiving at a less consistent speed than usual. I should just drive normally then?

[SKperformance]

it adjusts shift points for the tranny