Jd1368

Hey guys... As a continuation of my other post, I will be getting my 08 c4s back from the shop by the end of the week with a rebuilt engine from Porsche. Is there anything special I need to do to break it in? Just curious if there's any standard procedure. Thanks

chuck911

Well there is the factory recommendation, which unfortunately we can't tell you what it is because you don't say where your from! See, the factory recommendation is a North America thing. Nobody else gets told to baby it. And yet you will hear tons of people tell you to do just that. Usually when someone tells one person one thing and anther person something completely different and you find out about it, their credibility is pretty much shot to hell. This is the situation with the factory regarding break-in. But don't take my word for it. Check it out: https://rennlist.com/forums/991/8250...ery-diary.html
Scroll down to just below the third picture.

Then on the other hand there is a very large body of evidence, experience and solid reasoning behind the advice to not only not baby it, but to run it as hard as you can as soon as you can and as much as you can. This I like to call Seat The Rings because that's what you're doing with all this early-on full throttle driving. http://www.avweb.com/news/maint/1828...l?redirected=1

The contrast between the science behind STR and the faith behind the factory could hardly be more stark and clear.

May you choose wisely!

Bruce In Philly

IT still makes no sense to me why USA is different.

I did read that the first six month of owning any sports car is the highest for accidents.... so maybe that is the reason.

Regardless if it really OK or not, engines do wear and produce metal particulates when new or overhauled. Some reading:

1) http://www.shell.com/global/products...-30071255.html
2) http://deepblue.lib.umich.edu/bitstr...38/0000180.pdf

There is much out there. Of course, this wear and running at high RPMs may be irrelevant, but engines do wear and produce particulates. Break in is real. Is high RPMs during this period bad? Used to be.

I still don't get why high RPMs for Americans is bad.... and what is the business benefit to limit it in the owners manuals... I don't get it.

Peace
Bruce in Philly
2)

chuck911

I think you are right about liability being the reason. Another reason I have heard is warranty claims. Lots of hard accelerations necessarily leads to lots of hard braking and cornering. While I can hear the crowd (well a few, anyway) roaring "YESSSS!!!" to that, its gonna lead to more warranty claims. I knew a guy for example insisting on new brake pads under warranty when really he had just worn them out on the track.

Engines do wear and produce metal particulates not only when they're new, but throughout their whole service life. That's a factor in doing oil changes. The factor in doing STR drills down to the specifics of exactly how the all-important piston-ring/cylinder-wall wear occurs during the first few hours of operation. Strangely, in all the web searching I've done, the article above is one of the very few to clearly examine this and explain WHY its so important to run full throttle very early on. He even states clearly that, "My experience is that if the engine isn't broken in at 10 hours, it just isn't going to happen."

People usually don't ask about this until its already too late. They've already done a couple hundred miles or more. This is one of those rare times a guy can actually learn and do it right. I hope he does.

Lvt19672

Immediately take it to redline multiple times thru the gears, this will help seat the piston rings. Whatever you do, do not baby the engine.

Linnm

Read the Owner's Manual

Macster

Second this advice.

To the OP: Running a possibly new engine or one with some new parts, including rings, to red line will not seat the rings but just cause them to likely overheat and score the cylinder walls.

It is is really silly advice this running to red line or drive it like you stole it to "break in" an engine.

While seating rings is important if the engine has been run at all likely the rings are already seated quite a bit. A new engine fired up runs quite a bit differently until the rings seat. The thing runs rough and smokes and for someone who might not be aware of it has him doubting his engine rebuilding skills. But when the rings seat and the engine smooths out and the smoking stops all is right with the world.

My best advice is treat the engine like it is new and follow the manufacturer's break in guidelines.

Note these do not say to baby the engine but to avoid high/excessively high RPMs. Why? The engine new engine or new parts create extra friction and friction is heat and enough heat concentrated in a small area to possibly cause the oil to break down and the rings to score the cylinder walls or break the ring or worse.

Once up to temperature if you want to treat the engine to some moderately hard acceleration. This helps press the rings outward against the cylinder walls and if there is any seating left to be done this will help get it done. After the acceleration give the engine time to shed some heat.

Unless this is specifically forbidden by the owners manual, my advice would be at some point early in this break in process to change the oil and filter. If the engine is new, or has been opened up, it will shed a lot of trash mostly metal debris. If there is a pressure bypass at the filter this trash can be circulated through the engine for a while until the pressure bypass closes.

Certainly at the end of "break in" I'd change the oil. I see no reason to continue to drive the car, run the engine, with filthy oil and a filthy filter.

When I changed the oil in my new 2008 Cayman S at just 750 miles the oil filter housing oil was so full of metal trash the oil had a metallic sheen to it. There was enough bits and pieces in the filter to scare a dozen Porsche owners into an IMSB panic. But I knew this was to be expected and didn't panic. After another 750 miles I changed the oil again and there was just a tiny hint of stuff in the oil so little that it wouldn't photograph.

chuck911

Bruce, I didn't have time to read both articles earlier, but now that I have I want to give you a great big THANK YOU for linking them! The first one reads very similar to the one I linked to above, while the second one is very similar (and much more academically written) to Moto-Mans Break-in Secrets http://www.mototuneusa.com/break_in_secrets.htm

I quit linking to Moto-Man because so many people are simply incapable of getting past the source and presentation and write him off without ever dealing with the substance, which is EXACTLY what is in your second article. Early on it talks about cylinder walls being deliberately made rough not smooth:This is EXACTLY the way MotoMan explains it, that it full throttle be done early when this roughness is still there, in order to force rings and cylinder to conform perfectly.

It also mentions combustion acids contributing to wear, which is the same thing MotoMan writes about. This is what is behind the fact of a hard-used engine actually lasting longer than one that is babied from new. Acids wear parts down regardless of how hard the engine is used. Good ring seal- achieved with STR- greatly reduces acids.

Thanks again!

mgflyfish

So has anyone, I tried briefly and unsuccessfully-toi get a PDF of Official Porsche Owners Manual for Germany? I know there are multiple threads here from folks who have ED'd there cars and they report being told that once the oil is at temp that you ought to drive as hard as you like or some other words to the same affect--Perhaps an actual owner's manual from the Fatherland would finally resolve this issue?

chuck911

You're absolutely right about the factory being inconsistent. There are lots of posts from people outside N America with nothing in their manuals about babying it at low RPM's, nothing from dealers telling them to baby it, nothing like that at all. My favorite is https://rennlist.com/forums/991/8250...ery-diary.html where balaclava quotes the factory rep telling him: "for American customers, we must recommend you to keep it below 4200rpm, for everyone else we suggest use it as you normally would: careful while cold, then flat out.”

I don't know how much clearer it can be that this whole thing has NOTHING to do with engineering.

The main problem or weakness with this quote however is it relies on authority. Reliance on authority is a logical fallacy. An argument that calls on authority MAY be valid, however its validity would have nothing to do with the authority. It would still need to be a valid, compelling argument in its own right.

This is where the 4000 RPM limit fails. There simply are no mechanical engineering reasons for this. (This is probably why even when the factory is quoted, they are NEVER quoted giving any factual engineering specifications. Standing bet. PROVE ME WRONG!)

Seat The Rings, on the other hand, is extremely well thought-out, based on solid mechanical engineering principles, and backed up with thousands of examples.

There once was a fellow, claimed to write a book dictated to him by God. On his way leading his followers to the promised land, he walked up on a hill and said, this is it. The Pacific Ocean is just over the hill. And so the Mormons set up shop in Utah.

I would not hold my breath waiting for the pdf that will change the minds of the baby-it believers.

LexVan

Chuck, have you ever broken in a new Porsche motor? Air cooled or water cooled? How did you break in your new 997 motor? Have you ever driven a 997? Have you ever owned a 997?

Carmichael

Cloudspin

These are all questions I've had and thought about asking but I just noticed the Edit Ignore List in the User CP section. Handy!