The_Phantom

1999, you seem to know a lot about cars. Do you work in the automotive industry in some capacity or is it a hobby for you?

1999Porsche911

No I don't work in the automotive industry. Learning about engines and cars was a necessity due to me never having any money to hire someone to fix my cars. In the beginning, I quite often spent more doing my own repairs because of breaking things, but it was a good way to learn. I still have never rebuilt an engine where I didn't have at least some minor part left on the table after it was put back together. Most often a washer or two, My first engine was reassembled without a piston. That was funny.

Enjoyed it so much that I have always fixed and rebuilt my own and others for enjoyment. I do not like not knowing how things work which drives me to tear things down and put them back together. I was a tool and die guy for years and then went into banking. I retired from the financial services industry at age 35 (14 years ago) and have been a Venture Capitalist and equity trader ever since. It leaves alot of time on my hands to do what I want to do.

Larry Harris

Splain to me why the rev limiter works when you accelerate to say 7200+, but doesn't work in a downshift situation when trying to shift from 5th to 4th and accidently sitting second instead. If it were a true "Rev Limiter" it should work both ways.

Larry Harris

Splain to me why the rev limiter works when you accelerate to say 7200+, but doesn't work in a downshift situation when trying to shift from 5th to 4th and accidently sitting second instead. If it were a true "Rev Limiter" it should work both ways. The centrifical force of the engine @ 7000++ may have something to do with the rev limiter not working on the missed shift ??

1999Porsche911

The rev limiter is not a mechanical limit, but a computer controlled limit. When the engine reaches the limit, the computer cuts off fuel to the cylinders and therefore the engine will not continue accelerating. When you drop down a gear, the engine's rpms are dictated by the ratio of the tranmssiion gear to the engine and not controlled by the computer.

boolala

Well I followed the break-in "by the book" and have not had any measurable oil consumption in first 8600 miles..... and counting.

PV

Amen.

Would be great if we can discuss more of this type of items instead of colors.

I will try another topic or two.

The_Phantom

Yeah, my point exactly. If everyone had the same experience as you, the alternative break in theories would not be attractive to anyone and you are living proof of that. The fact that the 'batting average' of the owner's manual's system is not so high means that there are a lot of people that feel that their engine isn't properly broken in and are looking to try something different with their next engine.

P997C2S

The European owner's manual make no mention of exceeding a specific RPM. I followed the Euro "break-in" recommendations for my '02 996 and I intend to follow the same "break-in" with my 997. I had no mechanical problems with the 996 in almost four years and 21,000 miles of use.

boolala

No but it says to "avoid high engine speeds." What does that imply to you?

P997C2S

I would define "high engine speeds" as 85-90% of red line or approx 6120-6500 rpm. If 4,200 rpm was some "magic number" why wouldn't they say so outside of the U.S.

AFAIK Porsche tests new engines at full power on a dyno for 10 minutes after only a 10 minute warm-up period at the factory.

Pete Lech

Maybe they simultaneously seat the rings and flush the engine when they do this?

I have seen the dyno rig in use when they were building 996s, and it uses a remote oil supply, undoubtedly with special filtering to get rid of all the manufacturing dust and particles. After the motor goes in a car, they take the car out for a drive on the Autobahn near the factory. They wouldn't let us take pictures inside the factory.

fast1

One bit of advice to those that are concerned about proper break-in: don't ever buy a Porsche off the Dealer's lot. Order one.

A couple of years ago, one of my sons worked during the summer as a lot boy for a Porsche Dealer. He told me that on many occassions he would see guys test drive Porsches that had only a few miles on the odometer, and many of these guys would lay a patch of rubber as they drove off the Dealer's lot. My son asked the salesmen why they allowed the Porsches to be abused by the guys taking test drives. The salesmen would tell my son that the guys test driving the cars had all bought Porsches from the Dealer before and they didn't want to offend them.

It would be interesting to conduct a long term study on those "abused" cars to determine if they experienced more quality problems than those that were broken-in according to factory recommendations.

OCBen

Good advice.

P997C2S

The following is from the virtual factory tour. I don't think Porsche would subject a new engine with no miles on it to WOT testing if it was going to damage it or reduce its service life in any way.

Zuffenhausen Engine Assembly

"The following hot test is the final step in the engine production process. The engines are first of all heated up to operating temperature and then subjected to a functional test including full-throttle testing. Information in the form of up to 220 parameters is generated in this test of around five minutes' duration."