Engine Break-in

[Cuda340]

A website recommends hard acceleration and deceleration for the first 20 miles followed buy an oil change. The reason give is "that gas pressure from hard acceleration forces the rings to contact the cylinder around their entire circumference, which is the only way the rings can properly wear into the exact shape of the cylinder to seal the combustion pressure."

It also claims that if you follow the factory's break-in recommendation, you can lose 2-10% power.

Is this how you would break-in your new Challenger?

The website address is:

http://www.mototuneusa.com/break_in_secrets.htm

[Coach]

When I bought my Ram in '01, I specificly asked the service guys about break-in. The '86 Chevy PU I had before, GM recommended driving the first 500 miles on the freeway at a constant 45-50 mph. Anyway, the Dodge boys just said drive it normally. So I did. No problems yet. I would think that you would want to gently wear the motor and tranny in for a little bit before subjecting it to "hard acceleration and deceleration", though.

[Ragamuffin]

Well, I glanced over the article and I gathered it was for 4cycle engines /smaller engines like scooters, snowmobiles and such . I don't remember seeing anything about V-8's , trucks /automobiles !

[Cuda340]

Originally Posted by Ragamuffin

Well, I glanced over the article and I gathered it was for 4cycle engines /smaller engines like scooters, snowmobiles and such . I don't remember seeing anything about V-8's , trucks /automobiles !

You missed the heading of the article. It said:

"Although the examples shown here are motorcycle engines, these principles apply to all 4-stroke engines: Street or race motorcycles, cars, snowmobiles, airplanes any, yes...even lawnmowers!! (regardless of brand, cooling type and number of cylinders)."

After spending $40,000+ on a new Challenger, I am leery about his "hard acceleration/hard deceleration" advice. The only thing that I agree with is a quick oil change to remove metal filings.

[Ragamuffin]

Originally Posted by Cuda340

You missed the heading of the article. It said:

"Although the examples shown here are motorcycle engines, these principles apply to all 4-stroke engines: Street or race motorcycles, cars, snowmobiles, airplanes any, yes...even lawnmowers!! (regardless of brand, cooling type and number of cylinders)."

After spending $40,000+ on a new Challenger, I am leery about his "hard acceleration/hard deceleration" advice. The only thing that I agree with is a quick oil change to remove metal filings.

Ahh, well yes, I guess I meant to say 4-Stroke ! Since I'm not a mechanic & /or very knowledgable, are the V8's.V10's,V6's and even 4 cylinders =4-stroke machines ? I didn't quite think Aggressive break-ins are the way to go either. I mean with all the testing that must or does go on I would think the manufacturers would have told us if this above stated method would be the proper way to break -in ! In fact does anyone know what the race car drivers/teams do for Nascar or Indy types or are those race engines "pre-Broken in" before dropping in ???

[Cuda340]

Originally Posted by Ragamuffin

Ahh, well yes, I guess I meant to say 4-Stroke ! Since I'm not a mechanic & /or very knowledgable, are the V8's.V10's,V6's and even 4 cylinders =4-stroke machines ? I didn't quite think Aggressive break-ins are the way to go either. I mean with all the testing that must or does go on I would think the manufacturers would have told us if this above stated method would be the proper way to break -in ! In fact does anyone know what the race car drivers/teams do for Nascar or Indy types or are those race engines "pre-Broken in" before dropping in ???

An automobile engine is a 4-stroke engine. It has an intake (induction), compression, power (combustion) and exhaust stroke.

The two-stroke cycle is usually used by lawnwowers and motorcycles. It completes the same four operations (intake, compression, power, exhaust) in only two strokes (linear movements of the piston) rather than four. Thus, there is a power stroke per piston for every engine revolution, instead of every second revolution.

I agree that it would be interesting to know how NASCAR engines are broken-in.

[Cuda340]

I have been researching the web for expert advice for engine break-ins. The consensus is to let the engine warm up. Then, drive normally but not a continuous high speeds for the first 500 miles.

Occasional quick bursts of speed followed by quick deceleration during this period, is beneficial. Applying loads to the engine for short periods of time causes increased ring pressure against cylinder walls and helps to seat the rings. This is especially important because you are "BREAKING-IN" the engine with heavy duty oils. The rapid deceleration increases vacuum and gives extra lubrication to the piston and other assemblies.

If the wrong type of oil is used initially, or the break-in is too easy, rings and cylinders could glaze and never seal properly. A fresh cylinder wall needs some medium to high engine loading to get the piston rings to seat properly.

Most of the engine experts warned of the danger of breaking in the engine too easily and ending up with an engine that will always run slow (lose 2-10% power) whether it is from tight tolerances, inadequate ring seal or carbon buildup.

Also, after 500 to 1,000 is is important to change the oil and filter. (You can switch to synthetic oil but not before the first oil change).

[Ragamuffin]

Originally Posted by Cuda340

I have been researching the web for expert advice for engine break-ins. .

Occasional quick bursts of speed followed by quick deceleration during this period, is beneficial. Applying loads to the engine for short periods of time causes increased ring pressure against cylinder walls and helps to seat the rings. This is especially important because you are "BREAKING-IN" the engine with heavy duty oils.
Most of the engine experts warned of the danger of breaking in the engine too easily and ending up with an engine that will always run slow (lose 2-10% power) whether it is from tight tolerances, inadequate ring seal or carbon buildup.

Interesting ! Do you mean {/or I wonder if } heavier duty oil is used from the factory :just for this reason ?? Ok, now Part 2 == this about ,' the engine experts warn of breaking in too easily !! Well, what do they expect older folks, most woman [ and guys too] to do : really jump on it and as soon as they do some Policeman/woman will be in rear view mirror ! Then, they'll have some splaining to do ! !!

[Cuda340]

Originally Posted by Ragamuffin

Interesting ! Do you mean {/or I wonder if } heavier duty oil is used from the factory :just for this reason ?? Ok, now Part 2 == this about ,' the engine experts warn of breaking in too easily !! Well, what do they expect older folks, most woman [ and guys too] to do : really jump on it and as soon as they do some Policeman/woman will be in rear view mirror ! Then, they'll have some splaining to do ! !!

I guess the factory agrees with you. My wife's Honda manual says to "avoid rapid acceleration for the first 500 miles."

[Scat Pack]

I guess right after you buy the challenger, drive it straight to the local drag strip and run it in the 1/4 mile and then change the oil....that should take care of the rapid acceleration part....