EEBreh

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Join Date: Mar 2015

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Drives: "M" 235i

Engines are not really "Broken in" at the factory

Quote:

New Engine Break-in Conundrum By: Ken Koop

Since I was a young boy, I have always wondered why it takes so long to break-in a new engine–especially those built by Porsche. Most people driving new cars also do not fully understand the real reason for the break-in period. Are you one of them? A good friend of mine just picked up his brand new 911 Turbo and complained about the break-in period taking so long (2,000 miles, not exceeding 4,000 RPM). We have talked about this issue many times over the past few years, always coming up with many scenarios of why such a long break-in period is required. However, we have never agreed on a reasonable answer. Well, you are about to find out the reason Porsche requires the break-in period it has today. The answer comes directly from the engineers at Porsche.

I was on a recent Porsche factory tour and was watching an engine being built and dyno tested. Each engine is built by a single person on a moving production line. Porsche feels that they can obtain better quality control with one person building an individual engine from start to finish. In addition, each engine builder can assemble every type of production engine that Porsche produces and every gasoline engine is still built at the Stuttgart factory. It takes 2-3 ½ hours to assemble each engine, depending on the type. Afterwards, the completed engines are either used in the cars produced at the Zuffenhausen factory or are boxed up and shipped to Leipzig (for the Cayenne and Panamera) or off to Finland (for the Boxster and Cayman).
Before all of the parts are assembled for a particular engine; the pistons, connecting rods and valves are individually weighed and grouped together using similar weights to optimize performance. They are put onto a cart that moves along the assembly line with each engine block. This cart contains every part required to assemble that particular engine which includes each washer, nut, bolt, bearing etc… As a result, if any part is left in the cart at the end of the assembly line, then—Houston, we have a problem!At the end of the assembly line, the engine is filled with Mobil 1 Synthetic Oil. Each engine is then dry run (without fuel), pressure tested and checked for leaks. Every car coming off the production line is also run on a rolling road dyno. This enables all cars and engines to be tested at highway speed before they leave the factory.



Some of the engines are also randomly selected to be tested on a dyno stand before they are installed into the car. The assembly plant has 5 dyno rooms located directly off the production line. The day I was on the tour, there were around 40 engines lined up on dollies. Some of these engines were in the process of being tested for quality control purposes. Once the engine is bolted onto the dyno, warm water is circulated throughout the engine to bring it up to temperature. The operator then starts the engine and checks for the correct pressures and temperature before the actual test begins. Engine speed is then increased in RPM steps to about 80% of its red line (the engine’s maximum RPM). The entire engine run takes around 30 minutes. Since each engine type (Turbo, GT3, Boxster or Carrera…) has a different red line, all of the data is recorded and analyzed after the test is completed.After the engine is turned off, the engine is again checked for seal leaks and its actual HP is compared to its advertised HP. To pass final inspection, the engine has to develop, at a minimum, 100% of what its advertised HP rating is. Also, the engine cannot produce more than 5% over that same advertised rating. If the engine falls out of those parameters, the engine is rejected and then torn down to determine why it did not deliver the anticipated HP.

When the test was completed, a Porsche engineer came over to review the results. I couldn’t resist asking the question that I had been searching to find an answer to for all these years. I asked “why does Porsche feel it is safe for a new engine to run at nearly full throttle in the factory, while the customer must keep the engine speed to no more than 4,000 RPM for a 2,000 mile break-in period?” I thought that was a logical question and if I do say so myself-well stated! The engineer replied, “Herr Koop, you do not understand (that I already knew). When we do our engine test, the metals inside the engine never reach the temperatures they would when driven on the street since the test session is fairly short. In other words, the bearings, pistons and cylinders never get a chance to thermally expand to their maximum. Therefore, there is little wear on the moving components. But when you drive a car on the street, the engine parts expand considerably more because of the heat being generated from the engine running for an extended period of time. No matter how tight the tolerances are, there is always a slight amount of expansion in the material. The moving parts can wear quickly if exposed to excessive heat and not always in a uniform way. We also constantly vary the speed and allow the engine to run at both high and low RPM’s”.

“Porsche wants the engine to break-in slowly, which means it needs to maintain a lower operating temperature (below 4,000 RPM) and to allow all parts to adjust (wear-in) within their own thermal expansion parameters. This is also the reason why Porsche wants the owner to vary the RPM throughout the break-in period; therefore the engine doesn’t get use to one operating temperature range”.

“Porsche has been using Mobil 1 Oil since the early 90’s. With its superior lubricating properties, it takes many miles of driving (without getting the engine too hot) before the components actually seat (or break-in). Porsche’s own tests reveal that after 2,000 miles have been driven, all of the moving parts have had a chance to wear into their adjacent surfaces and then an increase in engine RPM is permissible.” I replied, “JA DAS SOUNDS GUT, when you explain it that way, it makes a lot of sense.” I thought to myself “You Dummkopf, why didn’t you think of that”.

The engineer commented that there were many other moving parts other than the engine that needed break-in as well. Wheel bearings, constant velocity joints, tires, brakes and transmission were just some of the other components that were mentioned.

So breaking it down into layman’s terminology, it all comes down to; higher RPM equates to more heat, which leads to greater expansion. For a new engine, that can mean uneven wear on certain parts if excessive heat is allowed to build up. In Porsche’s opinion, the thermal expansion of different parts and various materials need time to adjust to one another. Porsche’s time frame for that to occur is calculated to be 2,000 miles, with the heat restriction being 4,000 RPM. So simple; who woulda thunk.

Many experienced Porsche engine builders and experts on the Flat-6 engine state that the peak power of a Porsche engine is developed around the 20,000 mile mark. This coincides with the principle of what the Porsche engineer was telling me; “Break it in correctly and the engine will last longer and perform better”.

It only took me 45 years to find out the real answer to this puzzling question. After I returned home, I explained this to my friend. As for our ongoing debate, we now feel a solution to this riddle has finally been reached. Neither one of us had the answer to this complex question totally figured out, but we were on the right path! I am finally able to resolve another one of my life’s unanswered mysteries and now it’s been crossed off the list. I hope this helps explain one of your unanswered questions in the car world as well.

Sounds like engines are not truly broken in from the factory. I plan on following BMWs break in advice for their M cars. Keep it under 4k RPM for the first 1,000 miles then slowly bring it up. After it hits 1200 Miles I am going to follow

I am leasing the car but I'm planning to buy it out after. I'd prefer to spend $200 for the fluids and I will DIY.

Came across this interesting article from PCA (Porsche Club of America).Link: www.yel.pca.org/porsche-engine-break-in/ Sounds like engines are not truly broken in from the factory. I plan on following BMWs break in advice for their M cars. Keep it under 4k RPM for the first 1,000 miles then slowly bring it up. After it hits 1200 Miles I am going to follow Mike Miller's advice (this is an older version of the old school maintenance schedule, there is a much newer version). and change the engine oil, trans oil, and diff oil.I am leasing the car but I'm planning to buy it out after. I'd prefer to spend $200 for the fluids and I will DIY.

Testing the Quality of overhauled Vehicle Engines

In many cases, worn-out vehicle engines, mainly of trucks and busses, are overhauled instead of being scrapped. Of course, an overhauled engine should be as good as a new one, i. e. it should have the same technical properties, in other words, the same quality.

This quality can be ensured best by subjecting the overhauled engines to a power test, where the engine is loaded by a dynamometer and at least the maximum power and/or the maximum torque are measured at one or more rotational speeds. The specific fuel consumption, an exhaust gas analysis, the blowby, and the correct functioning of the control equipment (ignition, injection, electronic motor management etc.) can be further subjects of power tests. In case overhauling is performed by the manufacturer, the engines are normally tested after overhauling in the same manner as the newly produced engines.

However, a remarkable number of engines is not overhauled by the manufacturers or large overhauling plants, but rather by smaller, independent companies or workshops of organizations operating big fleets of vehicles, e. g. public transport organizations. They want to ensure the quality of their overhauling works by performing the same final measurements as the big overhauling facilities. Consequently, they also need an engine test bed. But their technical and economic preconditions are quite different:

The number of engines to be tested is much lower, in extreme cases only one engine per several days.

The number of different types of engines to be overhauled by an overhauling workshop can be as small as at an engine manufacturer's plant, e. g. in a specialized overhauling shop, or if a fleet is equipped uniformly; but for other workshops it can be practically unlimited.

Despite these preconditions, the expenses for every power test shall not exceed the amount incurred by a manufacturer for utilizing his testing plant.

In order to reach this objective

• the total investment for a test bed must be much lower than for a test bed in the testing plants of big overhauling facilities,
• the life must be long,
• the maintenance costs must be low,
• and the expenses for personnel must be low.
  

Furthermore, a test bed for small overhauling workshops should be suitable for different workshop organizations with small or high numbers of different types of engines to be overhauled.

Engine test beds (dynamometers) MP(L) 100 S ... MP 2x500 M of WEINLICH meet these requirements to an extent that has been unknown before:

Total Investment

Total investment is restricted to the price of the dynamometer itself and to an electric wall outlet. The dynamometer does not require a foundation or installations for cooling water. Training of personnel is normally not required thanks to easy operation.

Life and Maintenance

The life is practically unlimited because only the roller bearings are subject to wear. They can be easily replaced. In practice, however, this is usually not necessary because of the very long life of the bearings when used in the dynamometer.

If the test bed is not used, the air cooled eddy current brake contained in the dynamometer is not endangered by frost or corrosion as would be the case with water brakes and water cooled eddy current brakes.
The equipment has no cooling system which would require protection against frost or corrosion, or water conditioning to ensure the chemical quality of the water.

Maintenance is restricted to lubrication of the roller bearings in the brake and of the cardanic shaft connecting the dynamometer with the engine to be tested.

Personnel costs

Thanks to the easy operation, every employee can make the power test. No specialist is required.

Flexibility

Thanks to the mobility of MP(L) 100 S ... MP 2x500 M, they can be easily adapted to varying situations in the workshop as described below:

If there is only a limited number of types to be tested but with remarkable numbers per type, WEINLICH offers truck construction kits RWB suitable for assembling mobile engine supports for maximum engine weights of 300 kg up to 800 kg. These engine supports can be equipped with all accessories necessary for running the engine. So a certain truck can be prepared for a certain type of engine and preparing every engine of this type for power test needs a minimum of time.

If there are many different types of engines to be tested, WEINLICH offers an universal engine support to be transported by a pallet truck for an engine weight up to 2000 kg. Vertical and horizontal position of its supporting columns are easily adjustable, even with mounted engine.

Both, the RWB truck or the universal engine support, with mounted engine, can be moved to the dynamometer and then the engine and its support are quickly and easily connected to the dynamometer.

If the engines shall be turned in cold state before firing, a separate cold driving unit can be supplied. It can also be moved by a pallet truck. Connection of the engine and its support to the cold driving unit is as easy as to the dynamometer./p>

SSo every engine can be mounted on the appropriate supporting system, either specialized RWB truck or universal engine support, then maybe moved to the cold running unit or vice versa for driving without firing, then it can maybe run idle and finally it is moved to the dynamometer for power test. After power testing the support is removed from the dynamometer for dismantling the engine.

Hence, mounting and preparing of the engine for the power test and removal after the test do not occupy the dynamometer.

Further Features

Engine test beds (dynamometers) with air-cooled eddy current brakes are distinguished from water brakes and water-cooled eddy current brakes by the fact that they can be loaded with high power for short times only. This possible disadvantage is compensated for by the evaluation, display and control unit with the MP Computer by which every desired state of the engine can be adjusted very easily and quickly thanks to the handy method of operation proven for many years. A simple test report printing feature facilitates and speeds up the power test. Even the gravimetric determination of the specific fuel consumption only requires a short time thanks to the precision of the electronic balance connected to the MP Computer and to automatic printing of the result.

As a result, the efficient performance of power tests  provided by engine test beds MP 100... MP 2x500 M also reduces the expenses for power testing.
The test report is printed automatically. It is protected against falsification and forms the basis for the internal qualitiy assurance system, and provides evidence of quality to the customers.
Other documentation options are also available.