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Porsche's idea for a six-stroke internal combustion engine

motor1.com

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Re: Porsche's idea for a six-stroke internal combustion engine

#241

Post by lloeki »

Ccecil wrote: post #230
i_am_jl wrote: post #228

Earlier quoted context omitted.

I am sure that I don't understand the specifics of what Porsche is doing, but the article says the cycle is intake-compression-power-compression-power-exhaust. For that to be the case they have to be burning the same fuel and air mixture twice, and I don't understand the chemistry there enough to even speculate how it works. I think it's safe to assume that the second stroke is burning incomplete combustion products…

That actually makes a lot of sense merging with some comments from above. Second stroke goes lower and there are some ports to add air which are not accessed during the initial compression stroke...so the stroke is longer (higher compression) and more air is added to help with the reburn. Kinda sounds like combining the idea of the Miller cycle with a variable compression/stroke setup (see Nissan). There are a lot of…

> Miller cycle

Heh all along I'm wondering, what kind of thermodynamic cycle is it? By six strokes, does it mean there are actually distinct new phases to the PV graphs compared to Atkinson/Carnot/Miller?

Or is it just masquerading a well-known cycle underneath six strokes, only some parts are being optimised?

Re: Porsche's idea for a six-stroke internal combustion engine

#242

Post by brookst »

freeone3000 wrote: post #225
mrangle wrote: post #223

Earlier quoted context omitted.

ICE aren't niche, and there isn't strong evidence that they will be. There doesn't seem to be a public Come-to-Jesus moment for electric cars on the horizon. There seems to be solid reasoning behind that reluctance. That is, it will be difficult to displace. If phasing out ICE comes down to regulations only, then the antique interface analogy doesn't fit. >On the other hand of the spectrum, Hyundai Ioniq 5 N can emul…

>need to talk about the vanity attraction of a future all electric Porsche Future? You can buy an all-electric Porsche Taycan since 2019 - and it’s faster than the 911. Sports cars are fully adopting electrification, due to the huge torque numbers and high scalability. M-B and BMW of course, but also Porsche and soon to be Ferrari. It’s not just hybrids used for a boost (as in the decade past): those are full electri…

Unfortunately, EV’s are incredibly heavy, so “faster” is scoped to straight lines. As soon as you try to wrestle the 2300kg Taycan through twisties, the 1500kg 911 gets faster. And it’s still massively overweight compared to proper sports cars (the 911 is a GT).

Re: Porsche's idea for a six-stroke internal combustion engine

#243

Post by dangsux »

mrangle wrote: post #232
freeone3000 wrote: post #225

Earlier quoted context omitted.

>need to talk about the vanity attraction of a future all electric Porsche Future? You can buy an all-electric Porsche Taycan since 2019 - and it’s faster than the 911. Sports cars are fully adopting electrification, due to the huge torque numbers and high scalability. M-B and BMW of course, but also Porsche and soon to be Ferrari. It’s not just hybrids used for a boost (as in the decade past): those are full electri…

What's your point? Future or now, my point about vanity remains. I don't see any point in arguing over my use of the word "future" here. Again, "faster" isn't the most important metric for car enthusiasts. Which is what I described in my post. I know that's disappointing to people who would like it to be in order to claim total justification for electric motors. To say that "sports cars are fully adopting electrifica…

[dead]

Re: Porsche's idea for a six-stroke internal combustion engine

#244

Post by nolan879 »

_yb2s wrote: post #198
bell-cot wrote: post #185

Not to say that modern IC engines are any sort of "simple"...but there appear to be a lot more high-precision moving parts, under load, in their clever new crankshaft assembly. (Vs. traditional 4-cycle IC engines.) Obviously, Porche's target market isn't likely to care about that. But for possible down-market uses of this technology - are there any mechanical engineers in the house, to comment?

I drive a 24 year old Porsche and the engine already has a lot more mechanical complexity than most other engines- especially for their variable camshaft timing system. You’re right that Porsche and their target customers don’t care much. I’d say German engineering culture in general is to make things work better (when new), and not worry about complexity.

I Do Cars did a tear down of the M96 engine from a 986 Boxster S. Seeing inside of them, it makes sense how these motors cost $20K to teardown, rebuild and remedy Porsche's cost cutting in their first water cooled engine. I would own another 986 or 996 in a heartbeat. Tear down video: https://youtu.be/qrkALiq5hTU?si=0OmBKYcim-cflJEy

Re: Porsche's idea for a six-stroke internal combustion engine

#245

Post by brookst »

bell-cot wrote: post #185

Not to say that modern IC engines are any sort of "simple"...but there appear to be a lot more high-precision moving parts, under load, in their clever new crankshaft assembly. (Vs. traditional 4-cycle IC engines.) Obviously, Porche's target market isn't likely to care about that. But for possible down-market uses of this technology - are there any mechanical engineers in the house, to comment?

Not a ME but many modern ICE’s have tons of mechanical complexity in the valvetrain to handle varying timing and lift. From multiple valves driven by different camshafts to various ways to switch between camshafts or rotate cams, this stuff gets crazy.

Presumably Porsche’s design still has all of that, too.

Re: Porsche's idea for a six-stroke internal combustion engine

#246

Post by OJFord »

_yb2s wrote: post #199
OJFord wrote: post #69

Earlier quoted context omitted.

It says the goal is efficiency, so I assume the point is that if the first does say 80% combustion, then another cycle eeks out another 80% of 80% or whatever. (Brb, have an 8 stroke engine to patent.)

When Porsche says efficiency they mean making more power, not using less fuel. Porsche has a long track record of adopting efficiency tech and using them to make fast cars that still use a ton of fuel.

I'm not sure if that's supposed to be a correction, but if so I don't understand. The description of the two new strokes is as an addition to the normal four, one of which is the fuel intake, I was not assuming that decreases in quantity or anything. It could do, it's just orthogonal to the point - if you don't entirely combust whatever amount you inject in the first ignition , then the idea here aiui is to compress & ignite again to, yes, get some more 'power' out of it.

Re: Porsche's idea for a six-stroke internal combustion engine

#247

Post by typon »

kleiba wrote: post #231
kopirgan wrote: post #212

Know nothing about automobile engineering but somehow this feels like WordPerfect releasing a fantastic version for DOS when Windows was already capturing all the market. Btw they did that. Rest is history.

In Germany, where Porsche is from, sales of EVs are on the decline. The same is true for other countries in Europe as well. https://www.teslarati.com/electric-vehicle-eu-sales-drop/

This says less about consumer habits than about thr quality of EVs being sold in Europe and North America

Re: Porsche's idea for a six-stroke internal combustion engine

#248

Post by kleiba »

meiraleal wrote: post #234
kleiba wrote: post #231

Earlier quoted context omitted.

In Germany, where Porsche is from, sales of EVs are on the decline. The same is true for other countries in Europe as well. https://www.teslarati.com/electric-vehicle-eu-sales-drop/

In August. After a 38% tariff.

Check out the diagram at the top of this article: https://www.autozeitung.de/assets/styles/article_image/publi...

As you can see, compared to 2023, the sales numbers have been worse month for month in 2024, not just in August.

Re: Porsche's idea for a six-stroke internal combustion engine

#249

Post by kleiba »

kopirgan wrote: post #233
kleiba wrote: post #231

Earlier quoted context omitted.

In Germany, where Porsche is from, sales of EVs are on the decline. The same is true for other countries in Europe as well. https://www.teslarati.com/electric-vehicle-eu-sales-drop/

Think this is short term. Again no expert just based on what I see. Solid batteries give it few years then the maths will be very different

Not sure. Germans are traditionally both tech xenophobes and cheapskates - two arguments against EVs.

Re: Porsche's idea for a six-stroke internal combustion engine

#250

Post by kleiba »

typon wrote: post #247
kleiba wrote: post #231

Earlier quoted context omitted.

In Germany, where Porsche is from, sales of EVs are on the decline. The same is true for other countries in Europe as well. https://www.teslarati.com/electric-vehicle-eu-sales-drop/

This says less about consumer habits than about thr quality of EVs being sold in Europe and North America

The main reason is price.
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