Is there any actual proof whether hard or soft breakin better?

[OnkelMatze]

the manual is written by lawyers, not engineers (as mentioned before)
so I did the Darin Morgan - break in and my car runs like a devil

[ckaram]

Originally Posted by Russell James

Your correct in your thought of it just speeds up the wear in process. I have a couple of friends that are powertrain engineers and they do dyno testing all the time. They've seen green engines fail on dynos when taken to max load right away with no break in run time. It's very rare, but it does happen. Usually from a component that is a bit too tight. Such as a valve to valve guide clearance a hair too tight. Take that green motor red hot and it could stick that valve. Give it just a little break in run time, doesn't take much, and the parts will wear in and then be just fine when taken to max load.

The fact that most cars handle it just fine when beaten on brand new is more a testament to a quality build, than that is actually how it should be driven. Plus they've already had a little run time at the plant, in shipping, and moving around the dealer... so it really isn't that green anymore. In reality it's already had some pretty easy break in run time.

I've bought many brand new Vettes, F-bodies... over the years. I just drive them normal for a couple hundred miles, change the fluids, then drop the hammer at will. All have then dyno'd perfectly with numbers up there with the strongest out there. Even comparable numbers with those who claimed to be using the secret hard break in method. So they got their rings seated a couple hundred miles before me, woop de do.

I guess if you need to win a dyno shoot out at the 100 mile mark, the fast break in will help with that.

Good post, well said.

[Wilburbeest]

Makes sense that a hard break in would accelerate the normal wear process and allow the engine to break in faster. That having been said A lot of guys that have been building cars a while will usually tell you to listen to your engine builder on subjects like this (assuming the builder knows their ass from a hole in the ground). In this case your engine builder is GM's engineers, so I would go by their recommendation.

[tradosaurus]

Originally Posted by nards444

Well I think the engineers at GM are smarter than some of the witch doctors on Camaro 5

They are not!

[jackka]

Originally Posted by OnkelMatze

the manual is written by lawyers, not engineers (as mentioned before)
so I did the Darin Morgan - break in and my car runs like a devil

Ok, so then how do you explain the engine engineers from GM, Ford, and Honda quoted in a car magazine saying that the hard break-in will not do anything for you?

Were the lawyers putting a gun to the engineers' heads as they were being interviewed?

[brantley847]

Originally Posted by mikeSS

just drive it normal.... you have a warranty

Because those last forever and ever

[edneyens]

Breaking it in "driving it hard" doesn't make sense to me. All the parts are new you are putting more stress on them and risk damage or breakage that would not happen when broke-in properly.

Now I know we have a warranty which should fix anything that breaks but why - even if it is covered you put yourself in position of be without your car for some?

Now I do believe that the break in process should include cautiously revving the engine (no WOT), the higher revs have the pistons travel further in the cylinders and that is needed for proper break in.

So my 2 cents take it a little easy, vary the revs then after 500 miles or so drive normal.

[Milk 1027]

I broke it in with my right foot down on the pedal and rubber on the pavement. I didn't regret a second of it, life is too short.

[Oldrocker]

The answer to the original question is no. I've seen guys buy LS1 Camaros and rape them from the start and get 150,000 miles out of them and I've seen little old ladies that drive around town going the speed limit or below that have oil consumption problems under 50,000 miles. Anyone seen the Ultimate Factories Porsche 911 episode? The guy isn't exactly taking it easy on the road simulator with those 911's.

[brantley847]

Originally Posted by Oldrocker

The answer to the original question is no. I've seen guys buy LS1 Camaros and rape them from the start and get 150,000 miles out of them and I've seen little old ladies that drive around town going the speed limit or below that have oil consumption problems under 50,000 miles. Anyone seen the Ultimate Factories Porsche 911 episode? The guy isn't exactly taking it easy on the road simulator with those 911's.

We cannot make a blanket statement for cases like this....

There are people who baby the vehicle and it lasts 200k or 50k. There are people who "rape" them and have issues at 5k and also have some who can last 150.

The fact of the matter is it does add additional stress at a faster rate so why risk such an expensive investiment? We all do it once in awhile the first few weeks because we can't help ourselves...but mashing it consistently early on seems foolish.

[dragonZ28]

I drove mine for the first 500 miles very tame.
After that we put it on a dyno, and tuned out the rev limiter
We got it to 160 + MPH multiple times, during the test, and was going to go faster than that if we wanted.
Results were 396 RWHP, and about the same torque "almost straight line" across the board. After a 15% calculated loss from the drivetrain. This is about 455 engine HP "no mods". I have the dyno print out here somewhere.

Thanks, Roger

[jackka]

Originally Posted by dragonZ28

I drove mine for the first 500 miles very tame.
After that we put it on a dyno, and tuned out the rev limiter
We got it to 160 + MPH multiple times, during the test, and was going to go faster than that if we wanted.
Results were 396 RWHP, and about the same torque "almost straight line" across the board. After a 15% calculated loss from the drivetrain. This is about 455 engine HP "no mods". I have the dyno print out here somewhere.

Thanks, Roger

how high were the rpms going? is it safe to do that?

that's more power than the v8 from a v6 with no mods!

[formare]

Every one has an opinion so here is mine. Hard or soft breaking in really isn't the point. Avoid idling, vary the rpm as much as possible, do vary the load as much as possible - those that live in hill country have an advantage, high rpm is general not good for the first 500 as you may "glaze" the cylinder walls. Low rpm without load is generally not good cause you may not seat the rings and cylinder walls.

Back preassure ( down shifting and using the transmission to slow the car) is not ok as puts additional stress on the main journals until they have set then it's no big deal.

Highway driving generally a bad idea cause it's higher rpm with little load ( unless your in hill country). Backroads with few stop signs and hills are what you need for a perfect break in.

[dragonZ28]

Originally Posted by jackka

how high were the rpms going? is it safe to do that?

that's more power than the v8 from a v6 with no mods!

It is the LS3 V8 engine in this car. My son was in the drivers seat. GM claims 426HP from this engine. They may be claiming on the low side? Others have had similar results.
This car will definitely reach those speeds though. A lot safer on the dyno, than on the highway.