Break in. Hard or soft?

[callbay]

When I was 16 years old ( a lonf time ago) a good friend bought a new 390 CID Mustang fastback. The saleaman told him to break in in hard to have a fast machine so we drove it out from the dealer and out to a "safe" place and took it up to top end.

I have always wonderd if there is any truth to breaking in hard for a faster car or motorcycle.

Comments?

 

[caprice_2nv]

Yes. Even more so now as the rings usually seat quicker than older cars. There are some articles on the internet about this.

 

[SrDriver]

Follow owners manual. Don't drive with steady engine speeds. Owners manual should also recommend the amount of miles that you should drive with different engine and in some cases actual speeds for the break in.

Not a lot of requirements like in days past.

 

[Doog]

Originally Posted By: callbay
The saleaman told him to break in in hard to have a fast machine Comments?


Your friend listened to the salesman.......

 

[xBa380]

For what it is worth, I drove my xB with no intention of keeping it "gentle". Once up the temperature, I would floor it without a worry. What somebody said above, avoid steady engine speeds for long periods of time the first few hundred miles.

I am now at 80K and burn almost no oil on an engine that tends to have some oil burn issues (2AZFE) from what I have read. Who knows if it is related, but driving it somewhat hard when new did not hurt anything, and my UOA's show less than average wear on my engine every test.

 

[OtisBlkR1]

"Break it in how you intend to use it" is what ive been told by more than one professional builder. Yes there is alot of information on the web about this, a race engine or high performance engine that will be used hard.. break it in hard, your D.D. probably not so much..

EITHER WAY most engines go through a durability test AT THE FACTORY where they are redlined for a period of time..

 

[Mr Nice]

Silly to abuse a brand new engine.

 

[LoneRanger]

Another break-in thread...

 

[Corvette Owner]

Originally Posted By: OtisBlkR1
"Break it in how you intend to use it" is what ive been told by more than one professional builder. Yes there is alot of information on the web about this, a race engine or high performance engine that will be used hard.. break it in hard, your D.D. probably not so much..

EITHER WAY most engines go through a durability test AT THE FACTORY where they are redlined for a period of time..

ns
GM requires 30 hours at redline for new engine designs if I remember correctly). Their C5 Corvette (1997-2004) LS-1 engine was run at redline for 27 DAYS!

 

[Donald]

Originally Posted By: LT4 Vette
Silly to abuse a brand new engine.


+1

 

[mechtech2]

Umpteen jillion cars are broken in by civilians who simply drive them.
And the results are perfect.
Nowadays, we don't have rough and loose engines. Factory engines are very well built initially.

So my opinion is to drive normally, avoid redline for a couple thou, and use full throttle at mid RPMs here and there.
A little aggression is OK and good.

 

[whip]

Ask yourself who knows the most about your engine? The company that designs, builds, and warranties it, or the salesman selling it? I'd follow the owners manual if it was my car.

 

[hattaresguy]

Modern motors are pre broken in, so just drive.

AMG for example breaks their motors in at the factory.

Its not the 1970's anymore...

 

[OtisBlkR1]

Originally Posted By: Corvette Owner
Originally Posted By: OtisBlkR1
"Break it in how you intend to use it" is what ive been told by more than one professional builder. Yes there is alot of information on the web about this, a race engine or high performance engine that will be used hard.. break it in hard, your D.D. probably not so much..

EITHER WAY most engines go through a durability test AT THE FACTORY where they are redlined for a period of time..

ns
GM requires 30 hours at redline for new engine designs if I remember correctly). Their C5 Corvette (1997-2004) LS-1 engine was run at redline for 27 DAYS!


wow, now thats something !

 

[spk2000]

Not exactly a car but a friend and I both bought the same 4 wheeler. he followed dealer recommendations of not going over half throttle for first 500 miles. I was not given that recommendation and went all out right away. Mine would run away from his in every gear and by a long margin. Probably at least 15-20 mph faster on top end and would leave him off the start as well. These were Suzuki's and likely used older motor technology than cars but I was very surprised by the difference it made.

 

[morris]

just drive it. but dont race it for a while. in the radio control world it seams to be a big deal. but thats methanol, and nitromethane.

 

[SteveSRT8]

Originally Posted By: callbay
When I was 16 years old ( a lonf time ago) a good friend bought a new 390 CID Mustang fastback. The saleaman told him to break in in hard to have a fast machine so we drove it out from the dealer and out to a "safe" place and took it up to top end.

I have always wonderd if there is any truth to breaking in hard for a faster car or motorcycle.

Comments?



Absolutely endorsed here. Third gen machinist in the family, says the rotating assembly is either right or wrong, rings seat in minutes. Why not expose any weaknesses early?

My car is a known oil drinker, yet my example doesn't use a drop, even at all day long HPDE's. Every new car needs full throttle for break in benefits like better ring seal, lower oil consumption, and higher power.

Note my owners manual language: "Full throttle is beneficial to engine break in"!!!

Previous posters saying that engines are run in at the factory is completely wrong for the overwhelming majority of cars produced. Some high end like HatterasGuy mentioned, but not your grocery getters. TEST MULES are run hard till failure, but regular production motors are RARELY run in in advance.

 

[sciphi]

Break it in hard. I did that with my Cruze. It runs very well.

The particular engine in my car wasn't run until the completed car moved off the assembly line. The way GM does things nowadays, the engine gets a no-fuel spin while still on the assembly line to make sure it's doing what it should.

 

[badtlc]

I'm in the drive-it-like-you-stole-it camp for the first few hundred miles. Seems to work just fine for me.

 

[Silverado12]

I've driven on back roads on my way to work instead of the interstate. That way, I can vary the speed a lot. I don't break them in hard, and never had an oil burner. But that's just me. Old thinking I guess.