Eric Der Knuckledragger typed thusly:
>Could you find out for me how the factory breaks-in brand new engines,
>especially small ones like is in my Neon. I know you're supposed to take it
>easy on them for the first 500 or so miles while the rings seat and
>everything "mates" to the next part but I'm assuming that the factory has
>already run the engines for a while after assembly to break them in.
Just about every mass-produced engine goes through "cold test" and "hot
test" at the engine plant before being delivered to the assembly plant
(which is often in another state or another country!). A "cold test" is
just that -- the long block (short block + head), filled and prelubed
(injected into the galleries) with oil (typically a straight 30W, some
high-end stuff like Corvette, Porsche, AMG Mercedes get Mobil 1 5W30), is
motored without fuel or spark to circulate oil and make sure all the whirly
bits are in the correct orientation relative to one another. A few more
dress items (intake manifold, exhaust manifolds, etc.) are installed, and
the engine goes to hot test. It's hooked up to a stand (NOT a dyno!) with
water, fuel, exhaust, and electrical connections, and started. The water
is at the correct operating temperature (195-200F), and the engine is run
for a short time with no load. Then it's shut off, unhooked from its
umbilicals, and racked for shipment to the assembly plant.
At the assembly plant, the car or truck is run on a set of rolls at the end
of line, not really against any load to speak of, while systems checks and
final alignment are set. And then it's run out to the storage lot, run
when it's loaded onto a truck or a train car, and run every time it's moved
after that.
>Since my new, again, engine is almost ready for me out in Salina, some 195
>miles away from my home, I'd like to make sure it's properly broken in
>somewhat before I drive it home so I don't get stranded at about the 100
>mile mark. :^\
If your fresh engine strands you during 195 miles of Kansas highway cruise
(which is VERY low-load between Salina and KC), your engine builder should
be buying you a shiny new one... at their expense.
What I used to tell my customers at the family's garage after I did an
engine for them was this:
1) vary the speed and load on the engine. No long, droning, cruise-control
highway runs. If you must drive on the highway, vary your speed
periodically 5-10 mph, and change between the top two gears (4th and 5th in
your case) to vary the RPM and load condition on the engine.
2) (This one is subject to some debate) No really high RPM operation. Wide
Open Throttle periodically is okay (that variable speed/load thing at work)
-- but short-shift.
Keep that up for 500-1000 miles, change the oil and filter, and change the
oil and filter every 3K-5K (depending on usage) thereafter (and other
fluids/filters, etc. as required), and you'll get a long, happy life from
your engine. I got 170K out of my '94 Probe GT that way before major
problems (notably a water pump, which in turn took the head gaskets with it
-- the innards and lubricated bits were in fine fettle and it didn't burn
any oil at all).
There are those who think if you take it easy on your engine during
break-in, it won't know how to run hard. Bunk, I say. "But what about the
modern adaptive electronics?" they whine. Bunk, I say. If you give the
mechanicals a gentle break-in to settle all the rotating and rubbing bits
in with their mates in a controlled environment, they'll get along a lot
better for a lot longer. Adaptive electronics will adapt to a
post-break-in change to a, shall we say, "more aggressive" driving style
just as readily as they adapted to the gentle break-in driving style.
That's why they're called "adaptive electronics" and not "learn once then
set in cement" electronics.
So go ahead and drive it home from Salina, Eric. You could even have some
fun and get off the I-70 superslab and take some back-roads, making it
easier to a) vary the speed and load on the engine, b) see some of that
faboo Kansas scenery (the wheat should be nice and green this time of
year...), c) break up the tedius monotony (wheat, wheat, wheat, wheat,
grain elevator, wheat, wheat, wheat, KSU coeds in Manhattan, grain
elevator, wheat, wheat, wheat...) that is I-70 across Kansas, and d) get a
whanging good case of hayfever (I prefer Benadryl, your weapon of choice
may vary).
Hope this is useful.
Jim Crider
autojim@att.net
|