Break in?

[DukeGaGa]

Love how anybody can make a YouTube video and be an expert

well I'm pretty sure that guy has a degree in engineering, so he is an expert.

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[Bullitt]

Love how anybody can make a YouTube video and be an expert

Did you watch the video? He's not claiming to be an expert (even though he does have a mechanical engineering degree), just showing you that several car companies spend tons of money doing low rpms break-ins on some very high performance cars. Common sense will tell you that car companies will avoid spending money whenever they can, so if they're spending money on low rpm break-ins, there must be a very good reason why. Hard to argue with that, but to each their own.

 

[BmacIL]

Did you watch the video? He's not claiming to be an expert (even though he does have a mechanical engineering degree), just showing you that several car companies spend tons of money doing low rpms break-ins on some very high performance cars. Common sense will tell you that car companies will avoid spending money whenever they can, so if they're spending money on low rpm break-ins, there must be a very good reason why. Hard to argue with that, but to each their own.

Same, and I work in this industry (almost 10 years in it, half in powertrain).

Abuse isn't good for new engines, no. I'd definitely shy away from a track day on a brand new car. Autocross? It's not as taxing on the powertrain as you'd think. Varying speed and brief excursions to the factory-set RPM limits and brief WOT events aren't bad for the engine and often help with ring seating and break in of other components that otherwise don't get taxed if you baby it for 1000 miles.

Things new engines go through before they even reach a dealer lot:
1) Hot or cold testing at the engine plant (meaning fueled, which is much less often, or just spun up at the crank), which does almost all of the initial cylinder liner wear-in
2) End-of-line dyno testing of new vehicles, on every car

As a side note, super high performance cars tend to have far tighter tolerances than our powertrains, which is tighter than the average economy engine. Low rpm break-in for something like that makes some sense, as there is more designed-in interference that needs to be overcome initially and slowly.

 

[tom_sprecher]

Love how anybody can make a YouTube video and be an expert

That guys has done a ton of car related engineering educational videos. Engineering Explained on YouTube. As an engineer I find them informational.

I don't know if he is an expert, whatever that definition may be, but he has several orders of magnitude more knowledge than apparently do most who post here.

 

[Bullitt]

Same, and I work in this industry (almost 10 years in it, half in powertrain).

Abuse isn't good for new engines, no. I'd definitely shy away from a track day on a brand new car. Autocross? It's not as taxing on the powertrain as you'd think. Varying speed and brief excursions to the factory-set RPM limits and brief WOT events aren't bad for the engine and often help with ring seating and break in of other components that otherwise don't get taxed if you baby it for 1000 miles.

Things new engines go through before they even reach a dealer lot:
1) Hot or cold testing at the engine plant (meaning fueled, which is much less often, or just spun up at the crank), which does almost all of the initial cylinder liner wear-in
2) End-of-line dyno testing of new vehicles, on every car

As a side note, super high performance cars tend to have far tighter tolerances than our powertrains, which is tighter than the average economy engine. Low rpm break-in for something like that makes some sense, as there is more designed-in interference that needs to be overcome initially and slowly.

Thank you for the insight. So I guess the conclusion is lower performing engines like the Mustang have higher tolerances and so even though a gentle break-in is ideal, cars like the Mustang can cope better with a hard break-in and therefore the gentle break-in isn’t absolutely necessary in this case most likely, even if Ford recommends it.

Personally, even if the Mustang’s tolerances are higher, I’d rather play it safe and treat it like a lower tolerance motor for the first 1,000 miles since Ford recommends it.

 

[Braski]

I would love to know if the stang I test drove before I ordered mines is; 1 still running, 2 making any odd noises and 3 how much oil is it burning? I know one thing my car definitely shifts better than that one did. That 1st to 2nd thud almost kept me from placing a order.

 

[LightningStorm]

I personally waited 1k miles then did an oil change before really stepping on it. Never passed 4k RPM before then. With advances in technology you dont really have to worry about break ins. I still personally like to do it for peace of mind but there are plenty of videos of dealers and such showcases new mustangs and redlining them and taking them to high speeds with less than 100 miles on them. Start letting her rip tater chip and change the oil at 1k

 

[bootlegger]

You seem to be glazing over the part that says "change up through the gears early". This implies not letting the rpms get too high, otherwise they wouldn't call it early. This means upshifting even before you usually would.

That doesn’t mean you can’t take it above 4K rpms. They are basically saying don’t constantly bounce it off the rev limiter. Like bmac, I also work in the industry. I spent 4 years in engine development and 5+ years in fuel system development. In the hundreds to thousands of validation engines and parts I have looked at, high load is always the biggest issue early and late in life.

 

[bootlegger]

yeah, a few times, not all the time. Also, force in one direction doesn't magically change to a force in a different direction, so rpm is still the doing most of the job of wearing cylinder walls, not the pressure asserted from gas blowing up and pressing on the cylinder wall, nor the pressure asserted to the piston.

Not sure what you are talking about here. High cylinder pressure can and does increase wear. It isnt about changing direction of the force, it’s about the magnitude. Cylinder pressure isn’t just has pressing the cylinder walls. This causes more force on the rings, which move along the wall. It puts force on the pistons, which is transferred to the bearings.

To clarify, I am not saying redlining the engine constantly is harmless. I am saying bogging the engine under 4K is more harmful than running up the full rev range. Basically, keeping under 4K is a silly myth. Overtaxing the engine because you don’t want to go over 4K is a bad idea.

 

[Bullitt]

That doesn’t mean you can’t take it above 4K rpms. They are basically saying don’t constantly bounce it off the rev limiter. Like bmac, I also work in the industry. I spent 4 years in engine development and 5+ years in fuel system development. In the hundreds to thousands of validation engines and parts I have looked at, high load is always the biggest issue early and late in life.

Again, there's nothing early about shifting at or near redline. I'm not sure how this can be misunderstood. If I told you to meet me somewhere earlier than we originally planned and you still showed up at the original time, that would not be early. If Ford thought it was fine to drive however you want, they would have said "drive/shift normally" or "be sure to shift before redline". I'm not discounting you and your knowledge/experience, but they say early for a reason. Like I said in my response to Bmac, a gentle break-in might not be necessary thanks to higher tolerances on less high-strung engines like the Mustang's, but if Ford says to take it easy and other companies are spending tons of money breaking in engines this way, I'm gonna do it. But to each their own :cheers:

 

[DukeGaGa]

Not sure what you are talking about here. High cylinder pressure can and does increase wear. It isnt about changing direction of the force, it’s about the magnitude. Cylinder pressure isn’t just has pressing the cylinder walls. This causes more force on the rings, which move along the wall. It puts force on the pistons, which is transferred to the bearings.

To clarify, I am not saying redlining the engine constantly is harmless. I am saying bogging the engine under 4K is more harmful than running up the full rev range. Basically, keeping under 4K is a silly myth. Overtaxing the engine because you don’t want to go over 4K is a bad idea.

Pressure on the cylinder rings doesn't transform to wear unless the cylinder is moving. And no, revving up the engine does more damage to the cylinder walls, compared to more load. More load, does more damage to the other components that is inline of the force, this is just pure physics, so if you want to argue about this, you'll have to talk to mother nature, since she decided what physics will do to things in this world.

Also, I think you're misunderstanding some fundamentals here, we're not saying keep the rev below 4k and flooring the gas pedal. What we're saying is basically drive gentle for the first however many miles the manufacturer recommends, things like flooring the gas, stumping on the breaks, revving to reline are all not considered gentle. Any mechanical parts will have imperfections, and these imperfections can be corrected if you treat them the way they should, and won't cause issues afterwards.

 

[bootlegger]

Pressure on the cylinder rings doesn't transform to wear unless the cylinder is moving. And no, revving up the engine does more damage to the cylinder walls, compared to more load. More load, does more damage to the other components that is inline of the force, this is just pure physics, so if you want to argue about this, you'll have to talk to mother nature, since she decided what physics will do to things in this world.

Also, I think you're misunderstanding some fundamentals here, we're not saying keep the rev below 4k and flooring the gas pedal. What we're saying is basically drive gentle for the first however many miles the manufacturer recommends, things like flooring the gas, stumping on the breaks, revving to reline are all not considered gentle. Any mechanical parts will have imperfections, and these imperfections can be corrected if you treat them the way they should, and won't cause issues afterwards.

This is what I am talking about:
https://en.m.wikipedia.org/wiki/Piston_ring#Wear_due_to_ring_load_on_the_bore

Aside from high cylinder pressure from lugging, this is also a know issue:
https://www.quora.com/Is-lugging-bad-for-a-modern-engine
http://www.enginelabs.com/news/video-how-lugging-will-destroy-your-engine/

I am not suggesting people floor the gas often. I am saying engine speed is less important than lugging at low speeds. Basically, if you have to put load on the engine, it is safer to do it above 4K rpm.

 

[Bullitt]

This is what I am talking about:
https://en.m.wikipedia.org/wiki/Piston_ring#Wear_due_to_ring_load_on_the_bore

Aside from high cylinder pressure from lugging, this is also a know issue:
https://www.quora.com/Is-lugging-bad-for-a-modern-engine
http://www.enginelabs.com/news/video-how-lugging-will-destroy-your-engine/

I am not suggesting people floor the gas often. I am saying engine speed is less important than lugging at low speeds. Basically, if you have to put load on the engine, it is safer to do it above 4K rpm.

No one is talking about lugging an engine. We're talking about normal (non-heavy) throttle applications, shifting at or before 4k rpms and being in whatever gear is appropriate for the speed we're traveling, so as to not lug the engine. Do you race around over 4k rpms all the time? The Mustang has plenty of power so that I can go anywhere I need to without passing 4k rpms. I only go into higher revs for the fun of it.

 

[DukeGaGa]

This is what I am talking about:
https://en.m.wikipedia.org/wiki/Piston_ring#Wear_due_to_ring_load_on_the_bore

Aside from high cylinder pressure from lugging, this is also a know issue:
https://www.quora.com/Is-lugging-bad-for-a-modern-engine
http://www.enginelabs.com/news/video-how-lugging-will-destroy-your-engine/

I am not suggesting people floor the gas often. I am saying engine speed is less important than lugging at low speeds. Basically, if you have to put load on the engine, it is safer to do it above 4K rpm.

I know what a piston ring is, but thanks for linking that. And you are still not understanding what I'm saying. I never said high engine load at low rpm, i.e. lugging the engine, is not doing damage. I'm just telling you that high engine load at lower rpm will not be playing a major role in wearing down the imperfections on cylinder walls. Just stop and think for a bit, if you have a piece of sand paper, and you're using all your strength pushing it against a block of wood, it will NOT scratch the surface and smooth it out, you will only be able to smooth out the surface while you are rubbing the sand paper against the wood surface, and the faster you rub the sand paper, the faster it smooth out the surface. But at the same, the faster you go, the hotter it gets, that's how the first humans got fire (by rubbing two pieces of wood again each other). It's the same principle here with the engine, the faster the pistons move, the more wear is done to the cylinder walls, and more heat is generated due to friction, and tiny imperfections on a mostly smooth surface will generate hot spots and this will cause the material to heat up unevenly, which is bad.

Engine load on the other hand is more like using a hammer banning on a nail, you don't want to bang as hard as you can at the start, you want to get the nail into the wall a bit first, then start banging real hard. And lugging the engine is not just only bad when the car is new, it's bad always, period.

So like I said, you are misunderstanding what we're talking about here, we are talking about in case there are some little bits that aren't so perfect with the engine, going red line right at the start might cause some unwanted wear to your engine, and you should try to avoid that if possible.

 

[2018OFPP1?2]

I follow the manufacturer's recommendation. FTW. :doh:

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