Fresh engine
 

So I've been a mechanic for 11 years and I was always told when you rebuild an engine you should never WOT or rev it very high for 500-1000 miles, this was always when I was rebuilding 350's etc. What say ye on the little 4 cylinder engines? personally I would never rev it until it had some miles on it. Recently I ran into a few people saying it doesn't matter. I had a discussion with an engineer tonight and he says the main bearings need to wear(break in) so do not rev it for a good amount of time. What do you guys think?

some people say to drive it hard from the beginning..Not too sure. I knot he owner before me drove it hard from the beginning and my car runs strong it dynoed a good amount higher than other ap1s that dynoed the same day as me. But id say u dont have to baby it but dont abuse it either.

With a brand new fresh motor your going to want to let it run for a little bit, at idle. Change the oil, Refill the oil and dont be revving the motor out, stay under vtec. Its like breaking in a new clutch, if you beat on it the disc might glaze over. So with a new motor you want your rings to seat properly, Id suggest driving like a grandma for 1000 miles, and really not begin to beat on it untill 1500 miles are on it and you get it checked out to make sure everything is dialed in correctly. Some motors you can build and boost the shit out of them, and its allright. I have seen it a few times and the cars still run great todat even with 28lbs of boost running threw them, and them making 500whp+.... But i know if i just put some doe into a new motor i would take it easy and break it in!

If this is a factory fresh motor the manual is very specific about the break-in of the motor.
Honda started using a type of break-in oil from the factory a number of years ago. Most of the analysis of this oil demonstrated it had a high moly content.
If your engine didn't come with the Honda factory fill, using Valvoline Extended Life 10W30 will work. The Valvoline Extended Life oil has a high moly content and is chemically similar to the Honda factory fill (made by Mobil). U.S. dealers can't get the factory fill for some unknown reason.
The theory behind the use of a high moly oil is that it allows the engine to break-in more gradually.
It's very important to stay out of VTEC (above ~6000-6200 RPM) until you have about 1500 miles on the car. I don't have my manual handy, but I think the number is good. It's also important not to push the engine hard during the first 800 mile (full throttle, dumping the throttle, clutch dumps etc.) Just baby it a little and drive smoothly.
Honda recommends you break-in the motor using varying revs - that means if you go on a long road trip, don't drive the same speed the entire way.
After I bought my car new, I took a couple days off and put the miles on the car in one trip. I varied speeds and occasionally drove in 5th gear for extended runs to work the revs up. When you get near the magic mileage, progressively work the car up in the RPM range (don't hit 1500 miles and then suddenly start red-lining your car).
After I hit 1500 miles I slowly worked it up to the redline over about another 100 miles. After I began working it up to the redline, I frequently redlined the engine for about 20 miles worth of driving. After that, I drove it normally.
Honda says it's important not to change the oil until the first scheduled oil change. I didn't go this route. I did my first change around 2000 miles and used Valvoline Extended Life. I went another 2000 miles and switched to Amsoil 10W30. I went another 1000 miles and changed the oil again (to get the residual conventional oil out) and then went to a normal change interval.
My car's oil consumption is less than a 0.25 qt per 3000 miles which is relatively low for the S2000, especially the AP1. I think it's due to both the break-in procedure I used and the fact I use Amsoil (probably the most stable oil you can get).

The manual states a break in period of 600 miles on the engine from the factory.

This is correct.

But, letting an engine idle to break it in is a preposterous recommendation. Excess idling causes increased fuel dilution in your engine oil, reducing its lubrication capabilities. Just drive it, and keep it under VTEC for 600 miles. I believe the rule of thumb is "below 60% of redline" - derived from a Lotus manual-- and IIRC, if you do the math for the Honda manual (suggested rpm limit / redline), it also comes to around ~0.60 (60%).

yeah, letting the car idle for excessive amounts of time is NEVER a good idea.

As for break-in, it's safest to go by what the manual says, but if you google search, you will be hundreds of different opinions on this.

The one I personally like is to run the car fairly hard for the first 20-25 miles, then change the oil. That'll take care of all the shavings. Then just drive normal.

Seems plausible, right? I've never been brave enough to try it, though. Oh, and I think that method came from a motorcycle racer. People seem to say that if you run the engine hard during break-in, that it'll put out higher dyno numbers than the same car which was babies during break-in.

I believe the manual also says not to keep it at a constant speed while driving (i.e. don't use cruise control) for those 600 miles. That would lead me to believe that letting the car idle (i.e. at a constant speed) would be a bad idea.

Don't forget that the F20/22 engines have the FRM cylinder liners/walls.
That material takes longer to break-in as mentioned in a TSB (?), they also recommended against the use of syn oil before 7500 miles IIRC to allow the FRM cylinder walls to break-in properly.
The F20/22 is not your "average" drive-it-like-you-stole-it-off-the-dealer-parking-lot engine.
The trick is to "know" when to follow Honda's recommendations and when not.
On engine break-in I would follow Honda.
(on 10W-30 viscosity I'm not!)

:hello:

[QUOTE=gomarlins3,Feb 16 2007, 03:06 PM]I believe the manual also says not to keep it at a constant speed while driving (i.e. don't use cruise control) for those 6000 miles.