Engine "break-in" question

[Tom Burns]

Since many of us will have to travel several hours to our nearest smart dealer, does anyone have any information about the engine "break in'' recommendations. It would probably not be a good idea to travel at Interstate speeds for extended periods of time for the first several hundred miles, so can a distant dealer transport the car and what would the cost be?

[spdickey]

Originally Posted by Tom Burns

Since many of us will have to travel several hours to our nearest smart dealer, does anyone have any information about the engine "break in'' recommendations. It would probably not be a good idea to travel at Interstate speeds for extended periods of time for the first several hundred miles, so can a distant dealer transport the car and what would the cost be?

Today's modern engines don't require the kind of baby steps break-in that they did back in the '50s.

I was the first driver of a brand new 450 from San Francisco to NYC last year. Our instructions were to keep it to the speed limit (65) for the first couple of hours (about 100 miles), after that we should be good to go.

We did have some initial problems with clogged exhaust systems on three of the cars the first three days. It was most likely due to the cars being held in a warehouse for over a year untouched (dirty fuel), and the converted emission system G+K did. The solution was a replaced muffler.

That problem should not surface on the 451, whole different engine and exhaust.

Worst case for you is to keep it under 90 for the first few hours. Drive slow, see America!

[Smartster]

The manual says the break-in period for the 451's is 1,000 miles or 1,500 km, ha guess Canadians get a break.

But yes spdickey is correct that engines these days don't need such a long break-in period, but how to break-in an engine is a question that is really mixed.

Here is the break-in steps that I've come to accept:

Keep in mind that there really shouldn’t be any metal to metal contact happening within your engine, other than the rings to the cylinder walls.

The rings are the ONLY things we are interested in breaking in or seating. What seats rings is cylinder pressure. Rings and pistons are designed so that cylinder pressure sneaks behind the compression rings and forces them out against the newly honed cylinder wall.

Why do I mention this? Because I want you to take your warmed up car out on the road, find a nice straight stretch and do a couple of full-throttle runs in third or fourth gear from about 2500-5500 rpm.

Each time you hit 5500-6000 rpm, snap your foot off the gas and let the car coast down to 2500 rpm while in gear, to pull high vacuum in the cylinders.

Repeat this step about five times and you should have a nicely mated set of rings and cylinders.

NOTE: When I say “full throttle”, I am referring to a normally aspirated engine. For a turbo or supercharged car, modulate the throttle to achieve about zero on your boost gauge, rather than full throttle. This would be roughly equivalent to full throttle in a normally aspirated car.

[spdickey]

Originally Posted by Smartster

The manual says the break-in period for the 451's is 1,000 miles or 1,500 km.

What does the manual say about breaking in the car?

[Smartster]

I don't have it in front of me but it says something like you shouldn't drive more then 2/3 throttle/rpms for the first 1,000.

Also that you should not engine brake (shift down to lower speed) also that you should not use the double shift down function that happens when you floor the gas.

But all thats really hard, especially the double shift down function as if you hit any hills or are trying to pass on the highway you need to use this otherwise good luck...

I have 500km on the engine and its running great!

[jwight]

Several schools of thought on this, lot of opinions, etc. Some people advocate breaking the engine in as you intend on driving it; so, go like crazy if that's how you'll drive or take it easy if that's how. Change the oil or not, don't think it really matters much any more; personally, with that extended warranty I'm thinking beat the hell out of it from day 1 and see what breaks while it's still under warranty. Time will tell.

[MP3SMART]

I got the alarm, there will be no breaking in !