There are a lot of different opinions regarding the correct break-in procedure for a new car. They range from http://www.mototuneusa.com/break_in_secrets.htm to http://www.enginesonly.com/break-in.html to http://www.faqfarm.com/Q/How_should_you_'break-in'_a_new_car to the old "Drive calmly for the first X,000 miles. Avoid hard starts and stops." They all stress varying the rpms and load for the first while (and changing the oil). They differ in amount of throttle and highest rpm during this process. What have you done to break in your 4.6L/3V?

 

Here are some of our opinions:
http://forums.bradbarnett.net/showthread.php?t=39052
I lean towards the make sure you are careful and the car is warmed up...then drive it normally (which for me is a little on the hard side with lots of easy drives too).

 

Thanks Karman. I did a search, but couldn't find anything useful. Your link is spot on!

 

After reading some of the other treads correct me if I'm wrong, but the cross hatched marks on the cylinder walls are from machining and are not intended to wear down the rings to fit better. If anyone has ever built an engine they will know that rings fit pretty tight and need to be compressed to fit in the cylinder. they will expand a bit as they wear. my take on the breaking in process is drive it like you would normally drive it from the get go. If you drive like a granny then be easy on it. If you drive like a mad man, drive her hard. I also recommend varying your rpm and also changing your oil after 500-1000 miles.

 

The hatch marks on the cylinder walls sole purpose is to seat the rings. The rings can only be seated by running the motor. The hatch marks will wear off, generally within about 500 miles or so.

Hatch marks have high spots on them and thus not from machining, or to be more specific are put there purposely by machining to perform a job as I described above. You want the rings to fit nice and tight against the cylinder wall and if there weren’t a reason to seat the rings you could machine the cylinder walls to a mirror finish and provide an excellent polished fit for the rings so there would be maximum compression.

Since it’s not possible to machine two surfaces perfectly so they fit with very little to no gaps, nor seat the rings without running the motor for a while, like 500 miles or so, hatch marks are machined into the cylinders in order to get the best possible seal between the rings and cylinder and that happens when you seat the rings. To seat the rings they have to rub against something so they fit, or conform, to the surface they are in contact with that will have imperfections.

It’s like when doing brakes. When you put new pads on and you want to get the maximum life you should have the rotors turned so the pads can properly seat against the rotor. However, you can still get the pads to seat even if you have a continuous grove in the rotor. The brake pad will simply wear to where it fits perfectly into the grove of the rotor, same principle with rings wearing against the hatch marks. As the rings wear off the hatch marks they conform to the shape of the cylinder wall.

What’s important with proper seating of the rings is taking advantage of the hatch marks before they wear off, or wear down. Once they wear down there is very little to no further seating that will happen to the rings. If they don’t get seated properly you can have blow-by which will cause a reduction of compression and thus loss of horsepower and possibly more then normal oil consumption.

 

I've found that this can be an absolutely endless debate, and after much reading, researching, and discussion I'm still not sure myself. Here are some of my personal observations though -

I had an '04 Cobra a couple of years back that I purchased new. I drove it hard from the first day that I took delivery. It by no means had a "soft, slow, and easy" break-in, and even made a few trips to the strip during this period. I also had the first oil change at 1,000 miles. I put it on a DynoJet at about 1,700 miles and it put 379 HP to the ground.

My current 'Stang, an '06 GT with a manual, was also purchased new (6 miles on the ODO in fact) and I broke it in by driving "normal". I let it warm until the idle dropped down before I drove it (a minute or two), did 90% stop-and-go city driving, and never revved it past 3,000 RPM for about the first 500 miles. Between 500 and 1,000 miles I still drove it easy but occasionally downshifted to pass, still not hitting the throttle hard and this was probably only 3 or 4 times anyway. After 1,000 miles I just drove it normally without really paying attention to any particular driving procedure, getting on it every now and then but mostly just shifting at or under 3,000 RPM. I had the first oil change at 3,000 miles and had it dynoed the next day at 276 HP to the ground.

Both of these cars made pretty respectable numbers compared to others of the same make and model. And I am just as confused about this subject as I was before I witnessed all of this...

 

Mine had 2 miles on the OD....I let it warm up and did a burn-out leaving the dealership. I have alway's driven her hard and have never looked back. She is doin just fine.

 

Thanks for all of the comments! I too am confused because of the anomalies that I have witnessed. Also some "identical" cars coming off the assembly line are just plain better than others. Perhaps their internal moving parts (while all being within certain ranges), are just randomly balanced better. To break-in any of them, it probably doesn't matter too much what one does, as long as one doesn't go on a long trip right after picking the car up from the dealer (and leaving it on cruise the entire way). Several months ago I read an editorial in Car and Driver where there was a comment made that BMW takes their cars on a track and puts them through the gears, prior to shipping to the dealer. The comment was not positive - something like, "hell it's not my car". Sonic Boom NH's comment about seating the piston rings properly, seems to be the only thing that virtually everybody agrees is important. So it's a matter of religion . . . we do what feels right for us . . . and may the horsepower gods have mercy on us

 

Yeah that's about it.

 

Personally, I used the http://www.mototuneusa.com/break_in_secrets.htm method.

I changed the oil using Dino oil at 800kms (~500miles) and there were visible pieces of metal in the oil drain pan.

The car runs strong, going for a dyno tomorrow.

So far, so good.

 

Who told you this?

The crosshatch in the cylinders is to facilitate hydrodynamic lubrication of the piston rings. It holds oil. Once it's on it's way to being gone, this lubrication fails, and the engines life is near its end. Hopefully this isn't in 500 miles, right?

Back in the day, the crosshatch was made without plateau honing. This means that the crosshatch peaks were sharp. During the first few minutes of operation, much of these peaks were worn off, making a flat surface on which oil could adhere and the rings could ride.

Now, Ford and **** near everyone else uses plateau honing. After the first hone, where the crosshatch is made, a plateau hone is used which knocks the peaks off. Now from the get go, the rings ride on a layer of oil on top of these peaks.

The rings are mostly "seated" when ford fires the car up on the line and an over zealous dude or gal drives the car to the staging area outside the plant.

To finish the job, when driving the car make sure you load the engine. Give it some gas, don't ***** foot around, and you'll knock any wayward points off the bores, gears, rod sides, whatnot, and get the clutch and brakes worked in. For my peace of mind I change oil after a few hundred miles on new engines, to make sure any machining residue is cleaned out. Then it's time for synthetic oil, but I usually go another 1000 miles or so, with dino, not because you shouldn't, but because of economics. Hate to dump 10 dollar a quart oil so soon. I think I'm probably being over protective doing even this, but new engines cost a lot of money.

 

I agree with eighty6gt the crosshatch is designed to aid in lubrication. Prior to plateau honing the rings would actually wear down the sharp peaks from the crosshatching. Once they are worn down into more flat plateaus a thin layer of oil coats the cylinder walls to aid in lubircation.

http://www.pfonline.com/articles/080602.html

http://www.aa1car.com/library/2000/ar90058.htm

 

Just drive your car normally. These cars don't need a formal break in.

Stop worrying about it and just drive it.

I personally drove it like I stole it as soon as I left the dealership.

 

The dealer I first went to had a black version of the exact car I wanted, but it was "used" with 900 miles on it, and I was afraid to buy it thinking that every joe who test drove it probably ragged it out and it would not be broken in properly. I could have saved $6k by purchasing that used '06 over the '07 I wound up buying new with 21 miles on the odo. After reading all this break in stuff I am a bit regretfull I did not just buy the used car and save all that money. Oh well. At least my '07 will depreciate less, but probably not enough to make up for $6k.

 

Quote:

Q: My bike comes with synthetic oil from the factory, what should I do ??

A:

LOL that's the biggest load of bulldinky that I've heard thus far.

 

I haven't got my GT yet, but I can give you my experience with my truck. I bought an F150 brand new in April 03. I had read an article that I can't recall where from, but it quoted a factory tech. Anyway his gist was that with todays tolerances and technologies, there isn't much of a "break-in" period any more. He did recomend the age old varying your speeds for the first 1K, but said you don't have to be afraid of RPM's. When I got my new truck with the 5.4, I changed oil with Motorcraft at 500, went to Mobile 1 at 1K, and 4K, and every 5K since then. I even towed my 24 ft travel trailer to the coast at 3K miles. Today my truck has 85K miles, and still doesn't burn a drop between oil changes. In fact, Not so much as a lightbulb has burned out. When I was ordering my Gt the salesman asked me if I was trading it in and I just . It's the best vehicle I've owned. (That's because I haven't got my stang yet)

 

One thing I noticed is that the Romeo made 4.6 2V V8 and the 4.6 3V V8 are very noisy compared to the Windsor made 5.4 2V V8.