autox
[Top] [All Lists]

Re: Engine break-in.

To: "James A. Crider" <autojim@worldnet.att.net>, autox@autox.team.net,
Subject: Re: Engine break-in.
From: Stan Whitney <dp25sdw@yahoo.com>
Date: Thu, 17 May 2001 07:06:13 -0700 (PDT)
I'd only add some runs to redline at low loads (1st or
2nd gear) after fully warm (like 20-30min. running) to
let the 'whirly bits' run against each other at those
speeds briefly.  

I did that with my '96 miata - drove it home from
tulsa on the turnpike, but slipped in a few 0-60 runs
along the way.   That motor always ran strong and
free. 

he back of my mind likes the idea of the engine seeing
all the speeds and loads that you will use it in
during the break in, really don't have a choice with
my current race engine - break in was doing pulls on
the chassis dyno.

As always, YMMV
Stan



--- "James A. Crider" <autojim@worldnet.att.net>
wrote:
> 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
Yahoo! Auctions - buy the things you want at great prices
http://auctions.yahoo.com/

<Prev in Thread] Current Thread [Next in Thread>