Hi everyone, I will be receiving my newly built Z51 and was wondering what you all have been doing to break the new car in properly? I have been reading different opinions like driving it like you stole it to keeping it under 4k rpm for the 1st 500 miles etc.. please advise the best procedure?
Last edited by smajicek; 03-06-2014 at 11:26 AM.
Thanks Steve Hidden Content
Ordered from MacMulkin on 1-27-2014, Shipped/En Route 3-6-2014, arrived in Mira Loma 3-20-2014, on its way to my local dealer. Arrived 3-27-2014 Hidden Content
2014 C7 Velocity Yellow, 3LT, Z51, Auto, CF dash kit, Carbon flash painted mirrors, tail and hood stinger,Black rims, Red Calipers, MRC, NPP, VIN # 1G1YM2D7XE5117615
I replaced the rings in an engine myself about a year ago and looked into this quite a bit. What I found was a lot of varied opinions. The advice I settled on was running it hard in short bursts. Essentially, you want to "physically wear the new piston rings into the cylinder wall until a compatible seal between the two is achieved." This take high pressure in the cylinders, which you will not achieve keeping under xxxx rmps, as GM (and every other manufacturer) suggests. What you want to avoid, however, is the cylinder wall glazing over with overheated oil and thereby preventing that interfacing. So you don't want to run it hard for long periods.
So if it were my new car, I would nail it on the on ramps, but I wouldn't do laps at the track in the first ~500 miles. A manufacturer will never tell you to run it hard, of course, for liability reasons.
More detailed information:
New Engine Break-in Procedure
More fun reading:
Last edited by FormulaRedline; 03-06-2014 at 11:51 AM.
Personally, I break all my street engines in by driving how I'd normally drive, with the exception of holding a steady rpm, this needs to vary. I use break-in oil ( like Roush break-in oil) it has a unique way of encapsulating the foreign material that comes from the cylinder wall initial wear, suspends it, and it will flow out at the first oil change, ensuring there will be the minimal contaminants left over to cause wear.
Now then, My racing engines get assembled, and brutally beaten into submission, as they get tore down between rounds for inspection and bearing replacement.
sure wish I were driving and not working.
What happens now days is these engines come prefilled with M1 full synthetic, a superior oil that provides excellent protection from friction, etc. This is great for an engine that is already broken in and rings have seated properly, but it also makes the ring seating to begin with a crap shoot (GM still has excess oil consumption as the #1 warranty related service visit) as this initial period from new the rings and cylinder walls need to "wear in" to each other for a good seal. After 400-500 miles a very hard glaze sets in and then there can no longer be any further seating (we seat rings and break-in our race motors 2 runs down the track, street engines the first 100-200 miles, and rarely ever have anything but the best ring seating one could hope for).
Here is what happens when an engine is not run hard enough to create enough load on the rings to overcome the lubrication provided by the oil used:
In the old days, and still today with aviation engines that the pilots life depends on it, break in oil (a conventional mineral based) came pre-filled and it provided enough protection for the bearings and journals IF driven easy the first 500-1000 mile, yet allowed enough friction for the cross hatch hone to seat the rings properly. It was then critical to drain and fill with a good oil and then could be driven hard. If you went from the showroom to the race track with break-in oil back then you stood a good chance of spinning a bearing or worse.
Today, marketing has conditioned the buyer to get in the new car and aside from put gas in, never open the hood or consider doing any maintenance until 10k or so miles when a DIC message prompts them to do so, so this has resulted in all the re-ring jobs since 1997 when the LS1 was first introduced (that and the piston slap that was addressed with coated skirts) and GM to this day takes the stance that "consumption of 1 qt of oil per 1500 miles is considered normal" when there is no way this should occur.
So, aside from immediately draining the syn oil before driving your new car and filling with conventional to aid ring seat, driving it hard (not unsafe, not abusing it) for several full throttle accelerations, and deceleration (rings need to be loaded with both for proper BMPE to seat properly) one can then drain and change oil/filter to remove break-in debris and be confidant that the rings have seated properly and oil consumption at a minimum, and power at a maximum. The heat cycling process is also critical, during this first 50 miles stop a few times and let the engine cool and then continue.
Now we recommend driving easy the first 50 miles so the ring and pinon mesh properly and the brake pads bed as well, but other than that, there is no real critical drivetrain parts needing any break-in.
Here are some links to back this up for the skeptics (remember, the engineers don't write the owners manual):
This one probably the most informative and detailed:
Proper Engine Break-In - AVweb Features Article
Break In Secrets--How To Break In New Motorcycle and Car Engines For More Power
New Engine Break-in Procedure
People will have their opinions about how to get the job done right as expressed above. I can find something to agree with in almost everything posted above with some exception. To me the most important part of proper engine break-in is to me the most difficult to do. That is the avoidance of running the same engine RPM for extended periods of time. I would think that job is even more difficult to do with the auto-tranny, but certainly possible. We should not forget that the engine is not the only thing that requires a "break-in" period. There are many parts of the drive line that need to mate together and brakes require a fair amount of attention as well to avoid glazing or other irregularities. Just read the manual and heed what makes sense to you.
Picked my Z51 up at museum last weeks and drove home (750miles). One thing that I couldn't believe, the car knows you don't have 500 miles and the redline on the tach is 4500. Once you cross 500 mile the redline automatically jumps to 6500. I also did not hold one speed for any length of time. Also, when you start the engine cold the redline goes down and slowly rises until operating temp is reached. The technology on this car is amazing.
Rodney and C.A.R.O.L.I.N.E. (Candy Apple Red, Outrageously Lovely, Incredibly Nimble Entertainment)
C.A.R.O.L.I.N.E. is a 2016 Long Beach Red, 3LZ, Stage 1, Z06 Coupe with an Automatic 8-speed transmission, the Spice Red Design Package, Competition Seats, a Carbon Flash Hood Stinger, and a Body-Colored Dual Roof Package. She has SunTek paint protective film installed on every painted surface other than on some of the vents' and grille's slats, G3 Carbon's "G3-O7" side skirts, GM StingRay Red Tail Lights, GM Rear Splash Guards from Trunk Monkey, ACS Composite Enhanced Front Wheel Mudflaps from West Coast Corvette, and her mufflers painted with POR15 Aluminum high temperature paint.
"...for several full throttle accelerations, and deceleration (rings need to be loaded with both for proper BMPE to seat properly)"
Which ever break in method you choose is up to you, but I know for certain from back in my drag race engine building days that the above is necessary. It is logical that you must load both sides of the piston rings and accelerationa deceleration is the only way to do so. I have done this with every new vehicle I have owned since the mid 1970s and am doing the so on my new Stingray. You can easily do this and follow the break in instructions in the owner's manual.
Good point, Scott. So it sounds like whether you want to run it hard in bursts or keep it reigned in, all the sources seem to be agreeing to vary RPMs and mix engine acceleration and deceleration.
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Last edited by Emmdmd; 03-07-2014 at 09:33 AM.
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