[QUOTE]Originally posted by PDX S2000:
[B]
Well, mine made 207hp, and 137lb-ft at 5k miles, so I doubt going into vtec occassionally has anything to do with slower/faster.

 

I have a degree in Automotive Engineering, and own a training frim that teaches engine repair for locomotives. Even with the incredible tolerances of an engine of this type, bearings must conform to the load, lube oir reacts with heat, combustion etc. to leave behing a protevtive coating on cylinder walls etc. These are just some of the reasons the manufacturers require limited RPM for an initial period of miles. Now that Ive said this, I'm the worst offender, I jacked mine op to 8000 rpm twice with 20 miles on it! I gaurentee the techs, and salesman who serviced and sold every one of your S2000's red lined your vehicle at least once!

 

I watched mine come off the transport truck with .9 miles on it. I drove it to the PDI Tech, and watched the whole procedure. I took the keys home with me before I was even approved for the loan. But, I used to work at the dealership.

 

I'm extra thick-headed today, wtromb, but could you please elaborate just a bit on your explanation:

"...bearings must conform to the load, lube oil reacts with heat, combustion etc. to leave behind a protective coating on cylinder
walls, etc. These are just some of the reasons the manufacturers require limited RPM for an initial period of miles."

I'm missing the connection between the two sets of factors -- such as bearings needing to conform to the load and the need to restrain rpms. How does limiting rpms relate to bearings conforming to the load? The bearings are made to withstand 9k rpm obviously. What exactly is happening during the gentle break-in period that allows those bearings to better handle the load?

Appreciate your expertise.

 

Bearings have a Babit surface, materials such as lead tin. These surfaces are extremely soft so they can conform to the load and embed debris. Even though tolerances are precise, as the engine loads, the babit material will be relocated by the crank, cam etc, in other words, it will conform to the load. However, I feel the real reason we must limit the RPM for 600 miles, is to provide the lube oil with an opportunity to develop a protective coating between the pistons, and cylinders. This is not just a micron film of oil, but as the oil reacts with heat, fuel, combustion etc. it actually leaves a protective oxcide coating. So the concern I have would have with operating at continued high rpm prior to 600 miles would be piston to cylinder scoring. This ofcourse could result in a loss of compression, and increased oil consumption.

 

Continued ... sure but an occasional run-up to 9000 during the first 600 miles ?

And what is magic about 600 miles? It must be a compromise. 9000 rpm at 100 miles must be much worse than 9000 rpm at 550 miles. 9000 rpm at 600 miles must be somewhat worse than 9000 rpm at 1200 miles.

9000 rpm at 500 miles for 30 seconds vs 9000 rpm at 500 miles for 30 minutes?

I know most of us are way too compulsive about our S2000's, and as cdelena is bound to say, what's wrong with following the manufacturer's recommendation. It's just in reality I doubt even Honda has tested the "badness" of revving to 9000 rpm at 600 miles vs 450 miles vs 750 miles. 600 miles (1000 km) must be a kind of "generic" recommendation.

I think it is similar to how in medicine we treat a lot of infections for ten days, but we don't have much data on whether 7 days is 70% as good as 10 days or 98% as good as 10 days.

 

I agree, I think the 600 miles is just a generic safe guard. However, check out the thread on oil consumption. I wouldn't be a bit surprised if these engines were operated at high rpm very early on.

 

The first time I got to drive a Stook was my car when it was at the dealers. It had 0 miles on the clock and the dealer told me it was OK to go to 9K when we did a test drive. It wasn't 'till I bought the car and had acess to the manual that I discovered the concept of "breaking in". I know that many German cars have their engines run in at the factory so in ignorence I assumed the Honda was the same. I just hope I did no damage!

 

[QUOTE]Originally posted by S2Kguy
[B] [QUOTE]Originally posted by S2000 Driver:
[b][b]

 

I agree with you 2kturkey... 1000Km, change oil and then...FULL POWER! That`s what i`m gonna do in two weeks...
(Tired of waiting)