I too am of the don't sweat it too much camp. Break-in used to be very important for piston devices (including pumps of all sorts). Today, with advances in oils and metals, I believe break-in is merely desirable and that only about 1 in 100 cars (a total guess) that are improperly broken in will suffer from either rings not seating or bearings/bushings seizing or galling.

Poorly seated rings is an immediate problem with immediate symptoms. So is a seized bearing/bushing (which is terribly more unlikely in a modern engine.) If the car is not showing smoke or using oil, it doesn't have a seating problem.

Used S2000s are the only "bargains" to be found. I couldn't be happier with mine.

 

The piston rings are supposed to create a tight seal in the cylinder ... with tolerance measured in thousandths of an inch. In order to make it fit properly, they machine the ring to be just a tiny bit larger than what they expect it to be. During break-in, the ring gets filed down by friction against the cylinder to have a precise fit and the rings will become highly polished. Improper break-in can prevent this from occuring properly and the rings may actually score the cylinder walls. This is a problem because the ring isn't sealing very well. The resulting blow-by is power loss and you could end up with long term problems.

Car engines are precision machines these days. With the demands the engine undergoes, I would recommend proper break-in for any car. While the car may have already been redlined already from the factory, that doesn't preclude proper break-in procedures. It's cheap insurance regardless of whose engine it is. Properly broken-in engines have been known to actually improve performance over time.

 

Many parts go through some type of break in period, but the interface between the piston rings and the cylinder wall is the biggest reason for a long break-in period. The purpose is to wear down both the piston rings and the cylinder walls. But they are not supposed to actually touch during operation. The cylinder walls are designed to retain oil which creates a thin layer between the two surfaces. When they are built, the cylinder walls are machined with a rough surface of ridges and valleys. During break-in, the tops of the ridges are supposed to be worn flat, while leaving valleys in between. This serves to hold oil and protect the engine. The rough surface on the cylinder walls also works to flatten the surface on the piston rings which is what gives you a good seal.

If a car isn't broken in properly you can have several problems. If there is too much heat from high loads or high-rpm driving, the oil can break down and permantly fill in the valleys in the cyclinder walls creating a perfectly smooth surface which does not retain oil well. This can lead to excess friction and shorter engine life. It also prevents the rings from wearing down to a completely flat surface. This can lead to a poor seal and can let oil into the combustion chamber causing smoking and using oil, and let combustion gasses past the piston ever time the cylinder fires, wasting energy after the sparks plug fires and losing compression before.

Something to keep in mind is that break in occurs very rapidly on a new engine and any engine in a new car will get some type of short break in at the factory. Even a few minutes on an engine dyno is enough for a large amount of break in will occur. Break in is not a magic yes or no type of thing. It's just a question of how well broken in an engine is. And honestly even if you were to go hard on it right from the dealer most of the time you would probably never know the difference. The only time where it is *really* crucial is when you rebuild an engine yourself. Then you go through a set of steps to break it in properly if it has never been started before. Screwing this up would very probably result in a problematic engine which would give you problems right away.

Personally, I would have an issue with a car being sold as new with 1100 miles. You pay a premium to buy a car new and have the peace of mind of not having to wonder what the guy before you did with the car. And even though chances are that you will never have any problems due to how it was driven, I would really take issue with the fact that Honda prescribes a certain break-in procedure which you were not even given the choice to follow due to the mileage. But if they don't take it back, really, I wouldn't worry too much. Probably the worst thing that would happen is that you might be down a couple HP because the tolerances are a little tighter than they would have been had it been broken in for longer.

 

I would like to thank everyone who provided their thoughts and knowledge into the decision regarding the 2001 S2k with 1,100 dealer miles for $28,000. This is a strong community of enthusiasts who all share a similar passion which shows in every discussion.

I have decided to cancel this S2k deal. In life it is important not to settle for anything less then exactly what you desire and wish for. Ultimately I am a person who wants to buy a new S2k and watch it be delivered off the truck and into my hands because this is such a huge investment for me and I will have this car until it turns to dust.

I still think this is an excellent time to buy an S2k. And so I am actively searching for a new 2002 Silver/Blk or Red/Blk that I can purchase before it arrives at the dealer. I am willing to buy it and wait months to receive it as long as I can watch it roll off the truck. I can only realistically afford $31,000 for these exact S2k's. If anyone can help in this search I would be eternally grateful, as I already am for the support and information I received regarding the deal I canceled.

 

Jman:

If you aren't comfortable with it, you did the right thing.

(However) I need to add a very important thing: COLD START!

You can run in an engine for 3000 miles for all I care, but if you don't ALWAYS take it extra easy the first couple of minutes and easy until the water temperature AND OIL TEMPERATURE are at normal, you will still destroy your engine in the long run.

Please everybody, keep that in mind!!

Happy Holidays,


Siepel

 

I couldn't agree more with Siepel. Reedz and I, since we installed the oil temperature gauges, have both noticed that the oil tempeature is about 127 degrees F at the moment three bars light up on the stock temperature gauge. Normal oil operating temperature, we have also recorded, is above 190 degrees, and goes consistently over 200 when the engine is being pushed. So the engine and oil are far from fully warmed up even when there are three bars on the stock temp gauge. I watch the oi temperature gauge now and don't push the engine or V-TEC until oil temp reaches 170 degrees, which takes a few more minutes after three bars register on the stock temp gauge.

 

Break-in is bunk IMO, I'll get flamed but so what. Engines today are machined with such precision that while there is some amount of seating it is so small as to be irrelevent. You engine will break-in regardless of how you drive it. Engines today and the manufacturing technology used to build them is so far advanced compared to even 10 years ago it's rediculous. I've not heard of anyone that's had any issue related to break-in. There are plenty of people that have babied the car for the first 600 miles and then blown the engine the first time they hit VTEC. It is also true that many people burn excess oil after proper break-in. I'm not saying that if you break it in according to convention it will have problems, I'm saying that if you don't follow convention doesn't mean you will have problems. In short, I don't think it matters.

My main issues would be about how the car was driven and if there are any hidden problem related to that which aren't obvious. It doesn't take much to burn the clutch or stress the differential or downshift and overrev the engine. I'd also be concerned about repaired damage, inspect it VERY carefully, inside and out and have a mechanic of your own choosing examine the car in detail. I don't think this is any different than buying any used car IMO. There are no guarantees unless you actually see the thing come off the truck without a cratch but even then...

 

Break in is important, irrespective of the car. But as cthree pointed out, any engine will break in anyway over time. The key is to do it right. Some manufacturers intentionally use softer piston rings to have better sealing over time once they are broken in. Also, some metals will change over a few heat cycles.

Many people forget that break in also applies to brake rotors and pads...

 

I have been a firm believer in proper gradual break-in procedure followed by many trips to red line and beyond. The reason you want to gradually break-in an engine of today is to get as much HP out of it as possible. An improperly broken-in engine will not get damaged, IMO it will have less power than one that is broken-in properly. I have followed gradual break-in procedure with my last three cars, all three have been noticeably more powerful than others of the same year and make.

1993 Eagle Talon Turbo AWD: Ran a 14.44 @ 93 MPH Completely stock: Still the best 1/4 mile time that I know off for a stock car.

1998 Prelude SH: Ran 14.754 @ 93.731 Completely stock: Still the best 1/4 mile time that I know off for a stock car.

2000 Honda S2000: 13.855 @ 100.356 MPH Completely stock: This was on a day that I had no traction period... Best s2k time known is 13.70... Could have bettered that time with a good launch if not for fragile rear-end and weak clutch that made me quit dragging car.

What does this have to do with break-in, obviously other factors such as driver skill and track conditions are at play, however with cars like the 5th generation prelude and Eagle Talon, many many attempts have been made by many people to beat these times throughout North America under all sorts of conditions and with different drivers for years. How come they have not been successfull? How come with all three cars, I always pull away a little from others with the same car in the same gear???? Is it the way I press on the throttle?

Another point:

My S2000 dynoed at an SAE corrected 210.4 HP @ 8300 RPMs and 140.8 lbs of torque @6300 RPMs. With a loss of 20%, that is about 252 HP and 169 lbs of torque..... In fact from 5300 RPM to 8500 RPM, the cars torque level never drops below 150 lbs at the crank... Some of this power is due to luck, however one cannot say that all is due to random luck. Some S2000s have dynoed as low as 190 WHP, the difference is 10%. This percentage is too big to be purely random occurrence especially from an engine company like Honda.

To summarize all this info: It cannot hurt to break your cars in properly, even the manual gives some basic guidelines, what more do you need. Everyone is entitled to do what they want with their cars, however seeing how much $$$ some people are paying to get a few HP on this car, you could go a long way by sacrificing some early pleasure for some future power and savings.

This ladies and gentlemen is my opinion and in no way do I sell this as fact.