Break in

Nowadays, with better engines and better built cars, is it still necessary
to break in the engine? If yes, how?

I have heard of some who recommend running at full open throttle on some
load to "blueprint" the engine. How does this actually help "blueprint" the
engine?

 

Most, if not all, car instruction manuals provide information on how to
properly break in the car.

 

On a rebuilt, we run it hard to sit the ring fast. On a new car that have
little break-in from the factory, you should try to break it in a bit. Drive
around like normal, but try to change the rpm. Do not let the rpm stay
constant, like cruising on the highway. The same could happens if you idle a
long time. Constant rpm set the piston rings and cylinder to wear at that rpm,
making them not as good they should be.

 

Modern CNC methods allow making parts which need less break-in and produce
less junk in the engine/oil in its early life. It's still advisable to
follow some break-in regime - work the max revs you use up gradually over
the first 600miles is usually what Honda recommends and make sure the whole
drivetrain gets acceleration *and* deceleration forces over varying rpm. I
usually try to stay off the freeway during break-in to avoid running at
constant speed and in top gear all the time.

A blueprinted engine is one which is built from parts made according to
blueprint drawing specs and not from a factory tolerance parts bin. I've
never heard the expression used as you suggest, though that may be a valid
approach to break-in of a blueprinted engine.

Rgds, George Macdonald

"Just because they're paranoid doesn't mean you're not psychotic" - Who, me??

 

I remember only two things: don't apply brake suddenly or hit hard or the
gas pedal and only need 600 miles break-in. I asked the salesman about vary
the speed he said no longer require and did not see in the manual for CRV. I
also asked about 3K miles change he recommend 5K special the first one.

Hai

me??

 

Yeah right, ask the salesman - he'll know what to do.:^)

Rgds, George Macdonald

"Just because they're paranoid doesn't mean you're not psychotic" - Who, me??

 

Yes, but not as critical as it used to be due to better manufacturing.
The 2004 Accord manual states 600 miles as a break-in period. Avoid
hard acceleration, particularly in first gear. Don't tow anything.
Change the oil at 5,000 miles or so. Don't brake hard if you can
avoid it, for at least 200 miles. Vary your engine speed -- this and
not flooring it are the 2 most important items IMO. Ultimately if
you're only keeping the car for 50,000, you can abuse the hell out of
it; the next owner will suffer.