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TOASTY
07-24-2002, 08:05 PM
did anyone have a problem staying below the 5500rpm limit? on occasion i like to rev very quickly to the 5500rpm limit without going full throttle. during the first 300 miles or so i went very easy on the breaks and clutch (slows shifts in s3). so far ive only accidently reved to 6000rpm about 3 times or so (this isnt a big deal is it?). i know a lot of people have very different philosophies when it comes to break in.. some say its important to rev quick and hard every so often, others say it is better to go easier on the engine... what are some of your philosophies?

dkh
07-24-2002, 08:17 PM
i didn't have much trouble keeping the rpms below 5500, keep sport off, don't use cruise control.

drive it at various speeds and at various rpms.

break-in is important, that's is why they have the silly sticker on top of your winshield. you will have plenty of time to gun the car after break in.

dvap
07-24-2002, 08:22 PM
i don't know, but you guys have more control than me. I used full acceleration a number of times during break in. maybe I'll pay the price in the future, but realize I used the pull and pray method in high school with no problems :)

David

Rick
07-24-2002, 08:38 PM
I'm not an engineer, however, my understanding is that the manner and style of breakin will vary based on the type of cylinder linings used and the material the pistons are made of. For the most part, the break-in period is really just to seat the rings and allow them to mate properly with the cylinder wall. The result is, over time, a tighter seal, higher compression, and more efficiency/power output.

I've been around motorcycle race engines for a while, broken them in on the dyno (heat cycles...) and given 'em a handful of tender laps then let it rip. I've had very good luck with them. Most of the free radicals will come out in the first oil change, and from there you are good to go. I've watched guys rebuild engines on Saturday night only to run them a few times (anxiously!), then race them on Sundays. There was an old saying around the paddock that went something like "break it in like a baby, end up with a baby's bike".

I've never built a car engine - I'm not sure what the differences are...but I would guess that avoiding high RPM, constant RPM, full load and steady load are all good advice. I can't for the life of me, come up with a reason why they (BMW) want you to do this for 1200 (!!) miles - unless there is something specific in the makeup of the pistons and/or cylinder linings.

Of course you also have to break in the brake pads, a technique which can vary from manufacturer to manufacturer, and also the clutch. A full-on race start on a fresh clutch can glaze it and essentially ruin it.

So for me... I'm driving the car..... not beating on it, avoiding full throttle/heavy load scenarios (which increase the ring to wall pressure and can cause scoring...) and waiting it out. I'm not driving it like a baby though...

As always, the usual disclaimers apply.... and YMMV... whatever happens, just enjoy your car and have fun!! :-)

cjg54
07-24-2002, 08:42 PM
<a href="http://forums.roadfly.org/bmw/forums/e46m3/archives/forum.php?postid=129013&page=11">Break-in advice from a pro.</a>

Craig<br><IMG SRC="http://members.roadfly.com/cjg954/IRTVFacing3.gif">
Craig

very good. Bimmerboy
07-24-2002, 09:15 PM
Did u bookmark everything posted on this board?

oddlycalm
07-24-2002, 09:17 PM
Remember two things; the S54 engine is assembled to tighter than normal running clearances, and it is a relatively long stroke engine, all the more so since it revs to 8000Rpm's. What might work with other engines is not likely to work with this one.

If you screw the pooch on the break-in, you will have nasty stuff like heat ripple in you cylinder walls, and premature wear on other parts. Bottom line is that you end up with a less powerful engine, and one with shorter service life.

I never got above 4500Rpm until over 1000mi because I could feel that the engine really wasn't ready to rev an higher prior to that. I finally got to redline at 3100mi, but this was not an engine that it felt good to rev as I was increasing the revs over those miles. Now that I'm starting to rev it higher and more often, it's coming into it's own. It's more powerful and it's revving more freeling.

I am using zero oil, even when driving hard at relatively high Rpm's.

oc


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