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Engine Break In - A Discussion

New 01/27/2005

It all started innocently enough with my joy of having the car finally come out of the garage under it's own power. Man did it go South. However there, as always, were interesting points that came out. Background: After installing the junkyard donor after the debacle in the desert, the #5 Rod Bearing decided to go to Jesus.
Eric made the decision that we need to go down to bare block, and do a zero mile rebuild. I could bore you to tears with the horror stories about Fords lack of support for the parts on this car, but that's a story for a different day.
Here's how it started

***dial up warnings** the .mov file will crush you - don't open it. For everybody else, again it's quick time format

**No I don't know the car wash kid, and no he wasn't sitting on a phone book.

At this point I was just overjoyed that SW9 was once again running.


What am I missing here Larry?

You drove the car out of the garage?

New motor?


That is wonderful to see the TR moving under its own power

You and Eric are to be praised for your skill and patience!

You may have addressed this, but did you do any performance
stuff (head work, balance etc) when you did the rebuild?

Don Mallinson
We toyed with the idea of a stroker, but after conferring with Doug, reality set in. But she is truly a 0 mile motor, well before she left the garage. Breaking her in nice and carefully. This ones going to have to last 250K more miles!!


***Here's where it heads South****

Going to be another slow one eh? :o)


What he said!!  Beat the crapola out of it, and it will run as well as my '99 and Ryan's '98. Slow-n-easy will give you another motor like the original......slow and a good race for Clare's car!!

Ron Porter

Too bad it is cold as hell, or I may recommend break-in using dino oil. 5F
is miserable break-in weather.

I drained the factory oil at 500 miles and changed (forever and always) to
Mobil 1 which is why I always thought my SHO was a half step off the pace,
(can't be my lard ass)

I don't want to talk foot ball no more.



Was probably related more to not treating the gas pedal as an on/off switch.

FWIW, one of the Subaru clubs had one of the Subaru engineers speak at one
of their meetings. Although Subies don't come with synthetic from the
factory, he said that anyone who wants to use synthetic should go to it at
the earliest opportunity, and the "break-in with dino" was BS.

Ron Porter

Reiterating what was said in previous posts:

Nice & Careful Break-In = Slow SHO.

Too many examples proving this to be true, as well as excellent results from
lead foots who bought the cars new.

Don't have 50 click yet. just want to make sure everybody shakes hands and is friendly. gonna have a couple spirited romps tonight on my way to pick up the NGS.

Larry Eck
Ron -
That car ran like a scalded Dog! . . . . for about 5000 miles. . .(indistinct mumbling. . . )
Larry is breaking in the motor the way I asked him to and suffering angst from exercising Massive Restraint. Baby steps please. This thing was never spun up under a factory startup sequence and frankly, I'd rather see a slower motor live for a 150/250 k than run like a bitch
for another 5000 miles. These parts are just now getting to know each other - this is a
rebuilt mingling parts from 2 engines - NOT a brand new block etc.
For the .2 sec a rough break in may offer - the other end of the life cycle does not interest me at this moment - If Larry wants to drive a FAST car, I'll throw him the Tbird keys for a day until He gets it out of his system.

Cautiously yours
Eric Lehmann
Lead Engineer on Larry's Rebuilds and still suffering the consequences
*last part added by editor*
Regardless of what the odometer may have read, I've got good reason to
believe that my car was up near the 150k mark and likely is still running
strong wherever the hack artist that got ahold of it has the motor now.
Having been inside that motor a few times, I didn't see anything to make me
believe that there is any correlation between granny footing and engine
longevity in these cars (tranny may be a whole different story for a
different day).
Never spun up under factory sequence may be true, but I saw a video of it
coming out of a car wash and putzing down the street. It had to get to the
carwash and I seriously doubt that it made it there on a car hauler. I've
got to believe that its been run longer than it takes them to get it from
the end of the assembly line to its resting spot on the lot before being
shipped off to a dealer. As for the parts getting to know each other, isn't
that what started this whole problem in the first place?
Its strange, I remember watching the video and hoping for Larry's sake that
it ended with a nice display of tire smoke. Oh well, I don't make the
payments or buy the parts for the repair (and it didn't stop me when I did).
Larry can have fun racing Clare if that's what floats y'alls boat.
Hey how did I get picked on in this. I have a factory replacement engine.. {motors are an electrical device} albeit 165000kms ago.. {car has 187000kms} and I do not granny drive it neither does Lori.
Tranny cooling in the winter. I would do about 250 miles on it. then let er rip..
Where's the fun in that ?

If you break her in nice and careful, she's always going to run nice and
careful. Drive her like your going to drive her....
But then again, if you break her in slow, maybe mine won't be the slowest
next time.....as you were.

Rick Glass
That's so true. My Mom has a 2001 SLO with the 3.0L flex fuel engine. I've
driven it on a couple of 120 mile round trips and didn't like the way it
responded or acted. I disconnected the battery, drained the brain, then
drove it like I stole it for a few hundred miles (without her).
Now my Mother tells me that there's a demon (j/k) in the car when she heads
to auctions. It pulls harder on hills, the throttle and transmission are
more responsive. She doesn't necessarily like it, but it puts the car into
a better position for offensive driving. And that is not a bad thing!

Synth in new rebuild. After the toasting that Amsoil took on the first one, I'm convinced.

Larry Eck
There has been some discussion elsewhere on the net about easy break-in's vs
aggressive break-in's. Pretty much all of them have shown that the
aggressive style is actually better for the engine - specifically, it get
the rings seated better. Less blow-by, more compression, more power. The
reduced blow-by helps longevity, the increased compression is obviously good
for power.

I've been building engines for 25 years and always subscribed to the
'run-it-like-you-stole-it' mindset with my engines. All of them ran awesome
and lasted as long as any engine out there. With the close tolerances of
today's modern engines, there isn't really any need to break it in easy to
allow for parts to 'marry'.

I disagree with Porter about the synthetic vs dino topic. If nothing else,
dino is cheaper and with the quick/early oil changes on break-in why spend
the extra on synthetic? But my main disagreement follows the reason an
aggressive break-in tends to make an engine run better. The thought is that
there are only so many miles/hours where the rings get a chance to seat
against the cylinder wall. Being aggressive at the start allows for a better
seat (which is why they tend to run better vs an easy break-in). Synthetic
IS a better lubricant than dino, so it WILL resist friction better. No, it's
not 'slipperier', it just resists friction better. That is a fact. Friction
is what you want for a good seat at the rings. So, why use synthetic for
this if it works against this? Even if only minutely?

Obviously, ring type and cylinder type will play a big part in all of this
and can render some of it irrelevant. But again, what are you losing by
going with Dino on a break-in? Absolutely nothing. And some folks have shown
that there is something to gain.

As Ryan said though, it is your baby. Definitely break it in the way you
feel most comfortable. Just thought I'd share a different viewpoint to give
you something to chew on!

Dave Garber
I agree about the ring seating. We did studies in college on ring failures on new engines and found the ones in babied motors burnt oil or had high blow by into the crank. They never seated properly.

List veterans, does anyone have the link to the old motorcycle article that described the difference in power output after an easy break-in vs hard? I don't archive anything but if I recall, it was at least 3 years ago that someone (Ron?) posted the link.

Well this certainly generated more conversation than I expected.
I haven't babied the car. I have kept it out of O/D and been running at various speeds/rpms for the first 50miles. It will be beaten like a mule this evening, as long as I don't find any splooge piles underneath when I get home this evening.
It went to the car wash first, cuz that's where it needed to go. 8 weeks of grit, oil dry dust, bla bla.
It feels very strong. I used Motorcrap Synth which was only 1.70 a qt for break in and it will see Amsoil once It goes to regular oil intervals.
Will probably swap oil at 250. I expect to see high RPM's tonight and get there quickly.
I'll be firewall playing tonight.



That looks familiar.

Ryan Dudek
Yep !!! It`s a Hot-Rod allright .

B.King 13
Run the dog sh** out of it . The whole engine break in thing was devised for the Chevy small block (Junk) and just an excuse for poor mechanics. If it`s going to break it will do so regardless of a break in period . Chevy engines just like to give up quick. SW-9 is a bonfire Hot-Rod after having more than one engine swap . Maybe it's time to get that SF your wife wants and max SW-9 to the hilt ?

B.King 13

I remember an article in one of the hotrod magazines many years ago about a
builder who used a coarse hone on cylinder walls and installed pistons with
no oil on the rings, with the idea that this would cause the rings to seat
faster. I never read anything about this again so I don't know if it didn't
work or if nobody else believed in it. I don't know what to think about it

Well, I don't agree with the idea that synth necessarily resists friction
better. Now, I'm not someone who spends hours on bobistheoilguy, but from my
occasional readings on the subject, synth is mainly better because it
doesn't break down as quickly.

What I have followed for every new car I've had since the 70s is to go at
75-80& of my normal driving for around 1K miles, change the oil/filter, then
go my usual 100% driving style. I did 1,700 on the Subie oil, then hit the
synth and am moving on.

If I did a brand-new engine that I built, I would most likely do dino for
the first change for the cost. I will only use synth for turbo or
supercharged engines due to the heat. After owning the first SHO for 10
years of hard use on pure dino (mostly whatever was on sale or had a
coupon), I am still a believer in the frequent dino change. My only
difference now is that I will do 6-7K changes on synth with the turbo, since
the engine is into serious turbo use over 3K....which the car sees a LOT.

Beyond the ring seating of a real break-in, the hard se is also thought to
produce a more efficient bearing wear pattern, and obviously prevents
bearing wear due to lugging (also a part of my "2K Rule").

For all of my new cars over the last "lotsa" years, mine have been on the
"better running" end f the scale, and I'm not that lucky as to always get
good examples off the assembly line. I am a firm believer in the proper
hard-running break-in.

Ron Porter
That's essentially what I was getting at. The fact that it doesn't break
down as quickly or, doesn't break down as much completely within the
parameters of the environment the oil see's inside of an engine, is why dino
is better. Saying that it resists friction better may not have been the most
accurate description! Heck, one of the easiest ways to demonstrate this
difference between synth and dino is on my 'ancient' tech-based Harley! It's
a simple air/oil cooled engine that really reacts noticeably to what
brand/type of oil I run in it. When I run standard dino oil, my average oil
temp is generally right around 210-215 degrees. With synth, it usually stays
right around 190-200.

Now, with a turbo car, I'd want to get synth in a bit sooner (plus, the
effects that a hard break-in has on the rings is accelerated by a turbo
anyway so I'd think you wouldn't need to take as long with this initial
step). I'm not completely familiar with the Subie setup yet (with regards to
the turbo), but when we were running the Grand National about 15 years ago,
synth was good, and recommended by the National Club at the time, to help
the turbo live longer. There were numerous reasons for this but one of the
main ones was for shutdown. At shutdown, the GN didn't have a system (from
the factory anyway) to keep oil circulating at the turbo. With dino, this
would result in the oil 'coking' at the turbo's spindle bearing. Using
synthetic would eliminate this.

And I agree about your 'luck' vs 'by-design' comment! It's no coincidence
that your cars have run on the stronger end of the perf scale. It's all
about the break-in!
Dave Garber

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