Quote:
Originally Posted by M235xi_EB
To properly break-in (or as some spell: brake-in) an engine, you must bring up the RPMs to the point at which you intend to drive it at. If you baby it and keep it under 4000 or 4500, the rings will seat in to that point and could have issues creating cylinder ridges at the point of TDC (top dead center).
Higher RPMs stretch out the metal parts. The pistons go farther up the cylinders and the rings then go farther too; seating the rings to the full and expected range of movement. Racing engines must be broken in to the RPM at which they will run or they will not perform properly.
The best way to break in an engine is to slowly bring up the RPM and do not (I repeat DO NOT) stay at one RPM for extended periods of time within the first 500 miles. Do not lug it or ride at 55 or 65 mph constantly in the highest gears at 1.5K RPMs on your commute. That is the worst thing to do. Best to vary your speeds, but more correctly your RPMs. It you must commute the car in the first 500 miles, use a variation of lower gears to get the RPMs up.
I use this procedure during the first 300 miles or so. Use the manual shift in the automatic transmissions to vary the RPM from 3K to 3.5K for a few minutes each and slowly bring it up to 4K (hold for a minute or two), then 4.5K, then to 5K for the same delay and then back down to 4.5K, then 4K, etc. Use a variation of RPMs between those listed. Repeat this several times. Do this on the Freeway when there is no traffic. There is no need to speed and load does not matter. Go to higher RPMs if you plan on running your vehicle at 6K, etc. For most, 5k to 5.5k is sufficient for quick accelerations. Racers will want to progress higher. The worst thing is to jump on the engine and rev it high and back down again quickly. Ease it up there during the first 500 miles.
All of this is at your risk and is my opinion from experience with racing engines. It is your investment.
P.S. I think the initial autobahn runs mentioned are very beneficial to new engine break-in.
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Correctamundo! This is exactly the way all of my cars have been broken in. No hard launches on the transaxle but lots of varying revs to seat the rings. Every Porsche and other perf car has always dynoed on the high end, most on the very high end of normal. Never ever had any issues.