Benefits of a hard break-in discussion

[LoneRanger]

Yay, another break-in thread !! It's an interesting topic, but pretty sure all manufacturers include a form of cold run-in at the motor assembly plant before transferring the engines to the vehicle assembly line. For what it's worth, like others here, I broke mine in using the high load limited rpm model. Once at operating temp, which comes up quickly in the Ford twin turbo 2.7 due to engine coolant circulated through the turbo housings in exhaust manifolds... once at temp I would give it some juice but let off before exceeding 75% of tach redline, and then let it decelerate a bit by engine braking to balance the break-in with vacuum pulls. The tow/haul driving mode was perfect for that, since it intentionally holds gears sequentially downshifting when you let off, for engine braking when towing. Didn't tow during break-in of course, just selected that driving mode on the shifter. Where I diverged from common practice is I left factory fill in until about 3900 miles. And then used one of my two free dealership oil changes, LoL !! I should be ashamed. None of that may have made any difference, but it made me feel satisfied that I "did it right." Ha.

 

[4WD]

As you point out … one is actually breaking in the entire drive line

 

[A_Harman]

Originally Posted by Ws6

My Z06 had very specific instructions. None of it involved WOT until 1000 miles. Also, the rings are pressed against the walls most when the engine is in vacuum. Engine-braking from a sensible rpm is the way. Not revving to the stratosphere. During break-in of my Z06, I noticed for the first few hundred miles, a lot of soot on the tail pipes, as well as oil consumption (about 1/2 a quart total, in 1K miles). After about 7-800 miles, the soot stopped. I tracked oil usage after the first change I did, at 1K, and it never used another drop that I could tell. The engine definitely needed breaking in. Beating on it wasn't the way it was to be done. When you do this, you spike surface and system temperatures beyond normal maxes, because the increased friction of rougher surfaces will do that. After the engine is broken in, these surfaces play nicer. The same happens with the transmission, and the diff gears. The real bug in the ointment is the brakes...which should be broken in HOT for some systems (carbon fiber rotors/ceramic pads are a perfect example). Gears like a gentle break in, brakes like a hard break in, and engine components vary, but I have found a sensible break in is best (driving in moderate city traffic, and engine braking, is a great method, actually).

https://www.youtube.com/watch?v=nvTzcNtaSLU That's a link to Jay Leno's Garage, where he test drives the new C8 convertible with Tadge Juechter along for the ride. Tadge makes the point many times that the C8 is power limited during the first 500 miles to protect the gears in the transmission and differential. Engine break-in is different than it used to be. Modern piston rings are thinner in section, are lapped during manufacture, and are running on bores finished with finer stones, so not much break-in is necessary. Most engines have roller cam followers these days, so special break-in procedures are not needed to protect slider cam followers. At Cummins, the automated break-in procedure for heavy-duty engines got the engine up to rated power within the first 20 minutes of a 30-minute test. The cylinder kit chief engineer said that if the engine was not broken in at rated power, the rings would not bed in to the liners, the cylinder walls would glaze, and the engine would have high oil consumption forever.

 

[ecotourist]

Something I don't understand is the old story of "if you don't break in the rings early, you can't break them in at all". How does that make any sense? If an engine is using oil at 2,000 or even 5,000 miles due to poorly broken in rings, why wouldn't an aggressive break in regime at that point stop the oil burning? If someone understands this, I'd like to hear the explanation. On the other hand, if a ring is broken, or the bore is scratched or uneven, or the rings weren't properly installed......

 

[A_Harman]

Originally Posted by ecotourist

Something I don't understand is the old story of "if you don't break in the rings early, you can't break them in at all". How does that make any sense? If an engine is using oil at 2,000 or even 5,000 miles due to poorly broken in rings, why wouldn't an aggressive break in regime at that point stop the oil burning? If someone understands this, I'd like to hear the explanation. On the other hand, if a ring is broken, or the bore is scratched or uneven, or the rings weren't properly installed......

Apparently you were typing in your note while I was editing the previous post ^

 

[JTK]

There's reality to this, but for the run of the mill passenger vehicle? Not so much. Fairly sure any of the ex-rentals I've bought didn't see their first OC until 8-12K miles. Never had an engine/trans issue with them for the ~80K miles and 3-4yrs I typically own them.

 

[buster]

I was reluctant to post another break-in post. I think all of the points above are valid. I don't think an elaborate break-in is necessary on most modern engines today. The thought behind giving a new engine a good amount of throttle is to create a scenario that will help build the cylinder pressure needed to push the rings out against the cylinder wall for proper ring seating. Is this true on all cars? I have no idea. I stand by just keeping it simple and varying the RPM with RPM increases up to 4k with moderate to heavy load. I'm not in favor of WOT to redline.

 

[willbur]

Originally Posted by buster

A GM engineer that at one time was a member on this site said high load was good for break-in. You can do that without high RPM. I think that is most ideal.

Yeah- I remember him "bobinsky"? Lots of good info but got banned from this site I believe

 

[JohnG]

Yeah. Told a lot of people the truth, but not what they wanted to hear.

 

[buster]

Originally Posted by willbur

Originally Posted by buster

A GM engineer that at one time was a member on this site said high load was good for break-in. You can do that without high RPM. I think that is most ideal.

Yeah- I remember him "bobinsky"? Lots of good info but got banned from this site I believe

That was his name, thanks! I couldn't remember.

 

[benjy]

hello! drain the oil HOT!! girlfriends conservatively driven from new 13 Malibiu 2.5L sucked oil from new + just got WORSE until trading at 66 thou, using recommended 5-20 was the WORSE. my new to me low rev 106 cu in 2013 Vic Hammer was purchased with 800 on the clock + after a dealer change @ 500 miles i bought it + it was using oil. i took it + ran to 6 thou RPM repeatedly with a slow cooling period between, after a few trips like that on the back roads consumption CEASED + still uses NO oil today. engines vary even today but a correctly built engine will prolly do well however its broke in. slow revving big V-twins are a different animal + need to rev + load the engine to seat the rings. my Vic uses modern coated aluminum cylinders that loose heat faster than outdated liners like hardly uses!!

 

[philipp10]

I don't understand why anyone would listen to a couple of clowns on the internet. With all the millions upon millions of engines having been built, wouldn't it make sense the manufacturers would of done a "scientifically conducted study" that takes out the ancedotal information and instead, use real data over many samples? I trust the manufacturers to have done this. The question I have it, where can we find these published papers?

 

[thescreensavers]

I broke my Camaro in doing high load low-mid RPM for the first 40-50 miles. FWIW I have zero oil consumption even after a track weekend.

 

[Ws6]

Originally Posted by krismoriah72

Do they break in cop cars? I bet they pin them to the floor every chance they get.. and still live on to become taxis.

Having owned multiple cop cars, they DRINK oil by 200K miles. I was adding almost a quart per gas tank to the last one I had, and then I forgot and it seized up.

 

[ARCOgraphite]

Originally Posted by ecotourist

Something I don't understand is the old story of "if you don't break in the rings early, you can't break them in at all". How does that make any sense? If an engine is using oil at 2,000 or even 5,000 miles due to poorly broken in rings, why wouldn't an aggressive break in regime at that point stop the oil burning? If someone understands this, I'd like to hear the explanation. On the other hand, if a ring is broken, or the bore is scratched or uneven, or the rings weren't properly installed......

The cylinder hone marks (asperities) are only fresh and sharp only for a short time. You have to use cylinder pressure to seat the rings. Just don't over do it. Just quick bursts of WOT to only 70% of redline and cool downs., Yes the bores are "cold" but cast iron has poor thermal conductivity and the piston is floating on oil which also doesn't have great thermal conductivity. so a few microns deep on the surface can be overheated. Moly iron rings are a bit more 'prolonged break' in tolerant than chrome rings, forged pistons with wide clearance. here you are breaking in and conditioning the bore morseso than the piston/rings set. The oil Oil Use metric isn't a proper indication of a great break in; rather Cylinder Balance and proper specific Torque Production IS.

 

[ARCOgraphite]

Originally Posted by Ws6

Originally Posted by krismoriah72

Do they break in cop cars? I bet they pin them to the floor every chance they get.. and still live on to become taxis.

Having owned multiple cop cars, they DRINK oil by 200K miles. I was adding almost a quart per gas tank to the last one I had, and then I forgot and it seized up.

Thats usually the valvetrain leaking I would guess.

 

[Ws6]

Originally Posted by ARCOgraphite

Originally Posted by Ws6

Originally Posted by krismoriah72

Do they break in cop cars? I bet they pin them to the floor every chance they get.. and still live on to become taxis.

Having owned multiple cop cars, they DRINK oil by 200K miles. I was adding almost a quart per gas tank to the last one I had, and then I forgot and it seized up.

Thats usually the valvetrain leaking I would guess.

I believe it was indeed the valvetrain. Like said though, MANY surfaces in an engine are affected by break-in. The rings are just one thing. Then you have the rest of the car...

 

[LoneRanger]

No, there is no time to perform any particular break-in procedures on most fleet police vehicles. And yes, they typically are placed in the patrol shift car pool with only a few miles on the odometer after all the radio, emergency traffic equipment, and decals are fitted, and get hammered to WOT from the word go, when on runs where lights and siren are authorized. That doesn't mean the Officer is driving without Due Regard, they are tasked with remaining within a speed reasonable for traffic, weather, and road conditions and generally prohibited from excessive speed in municipal and suburban surroundings. However, that doesn't preclude one from hammering it to WOT when breaking traffic at an intersection on a code 3 run as they depart the intersection. As far as I'm aware, none of the fleet line cars are having any excessive oil consumption issues, not the Ford's (Taurus-based AWD Interceptors and Explorers) and not the Pentastar V6 Chargers we have. The Detective cars, Ford Fusion 2.5L 4 cylinders (pretty much the base fleet model) see much lighter use but still get driven without any regard for a break-in process, from day one, and none of them are burning oil to my knowledge either. Once the factory fill is drained (4000 mile OCI's fleet-wide) they all get whatever bulk oil the maintenance contractor facility the city uses, puts in. Not sure but I think they are putting on Motorcraft and Mopar oem filters.

 

[dogememe]

Originally Posted by Ws6

Originally Posted by krismoriah72

Do they break in cop cars? I bet they pin them to the floor every chance they get.. and still live on to become taxis.

Having owned multiple cop cars, they DRINK oil by 200K miles. I was adding almost a quart per gas tank to the last one I had, and then I forgot and it seized up.

I don't know what cop cars you're buying but I've owned three Crown Vics, two ex-police and one ex-government-fleet and none of them burned any oil. And I certainly don't drive gently.

 

[Railrust]

When I bought my truck, break in was a concern...how long on that factory fill? RPM's too high? Too low? Not varied enough? I ended up changing the factory fill at 1,000 miles. I tried to take it easy that first 500 miles but I found myself driving up some huge hills those first few weeks. But I didn't beat on it, actually I thought I may have kept it too much in the 1,800 rpm range. Well, the thing uses 3/5's a quart to a quart over its 5,000 mile oil change intervals. Strange thing happened around the 45,000 mileage point...it stopped using oil between changes. Not sure if it's the oil I'm using (RGT) or the engine finally kind of "broke in", but I haven't used any oil in my last two oil changes. That's NEVER happened before. Don't really know why.