Petevb

All plastic is not created equal. Teflon is good to over 400 degrees, ETFE is impervious to UV, thermosets can be both stable at temperature and impervious to creep.

A quick search says Porsche is using Durethan BKV 30 H2.0 with 30% glass fill for the oil pan. It’s very stable, 200C+ service temperature, very high cyclic fatigue life. The biggest on paper drawback I see is that it gets quite brittle when very cold- bottom out on cold start in the arctic circle and you’ll have issues.

The amount of plastic in a modern car is staggering, from the engine compartment to the dash. Pull apart your dash and the air ducts inside it are plastic, the flaps that direct flow are plastic and the motors adjusting those flaps are connected by plastic gears. None of those parts will last forever and the new oil pan is the same. I doubt the oil pan will be close to the first to go, however- Porsche is pretty good about those things. That said they have run into issues before making engine parts out of fancy new materials- back in the early 70s they saved quite a bit of weight from the 911 case by switching to magnesium, only for those cases to start to crack nearly a decade later. Given the risk and reputational damage I don’t expect Porsche would intentionally risk a repeat even if claims were way outside the warranty period, but accelerated life testing is hard.

I will say that given the choice I’d take the plastic over my aluminum pan, for whatever that’s worth...

Dan87951

Two words. Coolant pipes. Coolant pipes installed on the 955 series V8 Cayennes were also glass fiber reinforced nylon and most of them failed by the 6th year of ownership. Historically these glass fiber reinforced parts aka "short glass fiber" do not do well when exposed to coolant, oils, and fuels -- these fluids accelerate the break down of short glass fiber parts. Simply put, I wouldn't be surprised if there was another class action lawsuit over these cheapified oil pumps that is similar to the plastic coolant pipes.

There are a few German motorcycle manufactures that are now using oil pump gears made out of short glass fiber and so far i'm not impressed. Some guys are having to replace them after 300 hours of use. Because of this, there are now aftermarket companies making oil pump gears out of metal. Using plastic for such a mission critical application is a bone head move, especially on a car costing this much. Just look at Porsche's track record on bone head moves, they sure haven't disappointed us over the last decade, so why would this case be any different.

groundhog

^^^ you have lost me . by shifting the goal posts to coolant pipes and Cayennes............what have these to do with (a) the base of the integrated dry sump and (b) sports cars ?

coolant pipes = use them or lose them and (b) cheap four wheels drives built to radically different specifications and standards............

Plastic is a wad term that covers "plastics" which can been very different and indeed not even plastics at all but plastic like. For example Polytetrafluoroethylene (teflon) has very different characteristics to UHMWP - as metals and alloys are used in a car so are complex organic products some of which are plastics.

Dan87951

You obviously didn't read my post.

tthellott T

Thanks for the raw material info, very useful.
I believe many of us are expecting some over-enginnering designs on GT variants for semi-motorsport applications; i guess we trust Porsche quality how those critical parts are manufactured and validated with accelerated aging. Same for the new piezoelectric injector design, hopefully a solid design.

Petevb

Sure (though that’s a different plastic and design). But do you think a) they want another lawsuit, b) they want the reputation damage that results from widespread failures, and c) they learned things from the coolant pipe failures (and other in engine plastic applications). And while you’re pondering, exactly how much money do you think they save by changing that part?

Divide failures such as the 955 parts by number of applications the failure rate is still exceedingly low. Virtually every radiator back to the 80s has had plastic end tanks with integrated cooling pipes, so all the boxers, 996s, etc. Many are now two decades old and are not showing widespread failures like the 955. Thus I’d blame that not on the material but rather a design flaw, and Porsche isn’t immune to design flaws regardless of material- IMS, etc. But they have a few years in the field already and will soon be using the plastic oil pan on virtually all of their sports cars. Given their experience, the recent push for durability in those cars and their testing program I trust they are not all ticking time bombs.

Plastic intake manifolds started in the 911 back in 1990, by the way. Scary back then, completely accepted and on all their cars today. And high temperature plastics have come a long way in the meantime...

Dan87951

Who cares about intake manifolds, radiators, and plastic end tanks. At the end of the day when those parts fail they won't require you to purchase a new engine. The point is Porsche is now trusting your engines ability to flow oil on a cheap plastic oil pump. Trusting your engine with a material that has a spotty track record of reliability when exposed to oil and fuel seems like a pretty bone head move. If you are happy with Porsche cheapifing their cars with various cheap *** plastic parts then keep buying them. However, you seem to be putting a lot of faith in Porsche engineers considering this is the company that brought us IMS, scored cylinders, D-chunk, 991.1 GT3 engine failures, and plastic coolant pipes. Looks like to me Porsche is motivated by cost and not longevity...

Petevb

This thread is about the integrated dry sump pan which changed to plastic. But it sounds like you’d prefer the sintered metal oil pump gears in the 997.2 GT3 that disintegrated gears and took out more than a few engines? I’d take the new pump any day of the week (though I’ll take the Cup car’s machined gear pump over either). Again- less about material, more about the design.

spdracerut

Just a note, many/most intercooler end tanks are made of pa66gf30 these days. The hot side will see temps of 350f.

Dan87951

How can you even argue the longevity of a metal gear over a plastic one?! Metal gears have a proven track record for well over a half century. What's the track record on plastic? Thought so! Just look at the plastic gears being used in BMW motorcycles, some guys are only getting 300 hours out of them before they need replacement. Confidence inspiring? No! Like I said, you don't become the most profitable car company in the world by building quality cars. See you guys at the next class action lawsuit.

Petevb

Because I have actual data instead of F.U.D. I personally know of over a half dozen early failures of the sintered metal gears in the 997 GT3 oil pump. It’s a known weak point, one the factory clearly knew about as they upgraded the part in the Cup cars.

But hey, plastic- scary, right? And there have been failures of a different plastic on engines by a different make so they must all be bad. Never mind that 9A2s have not shown any signs of a problem with far more cars in the field. But I’m sure that’s right around the corner- best of luck with that suit.

Dan87951

I would love to see this "actual data" you speak of because so far all you have is speculation. How can something that is so new be proven durable? You sure do have a lot of faith in Porsche's engineers. Just because they say it's good it must be. Right?! I think we all know Porsche's track record with engine durability over these last 10 years is nothing short of laughable.

You do realize if they machine the metal gears wrong they will fail. This is what happens when you use the lowest bidder as a supplier. I'll stick with the metal gears which have well over a half century of proven durability and reliability.

Petevb

Having designed parts that reside in tens of millions of cars myself out of (gasp!) plastic I guess I do. And while I don’t currently work in the automotive industry I do design parts that need to last much longer- at least 30 years. Many of our test programs and equipment are adapted from automotive- $150k super UV machines that simulate 100 suns of exposure and cyclic temperature and humidity testing with salt spray are the norm. Thus I have more than a little insight into the tests these parts passed before getting declared fit for service and how they are likely to age, along with visibility into plenty of metal parts that failed from poor design. In the end it comes down to the quality of the engineering, and on that point I would put Porsche’s recent work up against anyone you care to name. Yes they push the boundaries in a way that Toyota and others have traditionally not. Given that they have a strong track record of success, especially recently after the real dark days of penny pinching with the 996. But hey, vote with your feet- if you’re scared of modern Porsche engineering you certainly have other options. On the other hand if you’re scared of plastic... not so much.

Dan87951

Here's your modern Porsche engineering: IMS failures and lawsuit, scored cylinders, "D-chunk", cam adjuster bolt failure (958 Cayenne ruins engine), plastic coolant pipes lawsuit, 991.1 GT3 engine failures, Macan transfer case failures, Macan engine failures, PDK transmission failures (not rebuildable either), etc. Maybe Porsche should focus their efforts on trying to make their drivetrains last to at least 100k miles before they start using their customers as beta testers in their effort to reduce cost and up their bonuses.

I had a feeling your lively hood was tied to plastic components, no one goes to this length to defend crappy plastic parts unless their livelihood is on the line. If plastic is so good then why did Porsche switch the coolant pipes in Cayennes to metal?

Petevb

And older Porsche engineering? Is that a 944 Turbo I see in your stable? A water pump that’s a time change item, ditto the cam timing belt. The head gasket as well if you track regularly. Double walled exhaust piping and crossover which collapse. Ceramic inserts on the exhaust side of the head which fail. Front A arms that fatigue crack. Shift linkage bushings that wear and get sloppy. I could go on, and all well before 100k miles if the car’s used hard. Not to mention 20 hours and a transmission drop to do the clutch? So if you don’t like the last 10 years of Porsche engineering (post IMS failures era) which would you prefer?

Porsche is now making 10x the cars they were three decades ago- there will be issues. It also uses VWAG engines (as in both your Macan and Cayenne examples above)- technically not Porsche engineering. As for the 991.1 GT3 they own that, but then they were pushing record high corrected piston speeds for street cars, and they not only made it right but improved on them in the 991.2 GT3. Meanwhile the 9A1s and now 9A2s have overall proven highly durable, and Porsche’s consulting engineering program (secretly designing for other manufactures) is as busy as it’s ever been.
Not in the least- I use very little plastic these days. My livelihood is tied to solid engineering and product development across multiple industries- the right tech for the job. Without bias.