Ultralight Diesel Fuel Burning Small Wankel?

[Dockhead]

Wouldn't something like this:

40S - 5BHP - Wankel Rotary Engine | Advanced Innovative Engineering (UK) Ltd

Be fantastic as a dinghy outboard. 5 hp out of 2kg (!!!).

Better yet, it can use diesel fuel!!!

Downside is likely to be that they cost $100,000 each, as they are designed for military use

[capngeo]

Tax dollars at work

[transmitterdan]

Time between overhauls rated at a whopping 500+ hours. Makes my like my old fashioned reciprocating clunker even more.

[Dockhead]

Originally Posted by transmitterdan

Time between overhauls rated at a whopping 500+ hours. Makes my like my old fashioned reciprocating clunker even more.

That's pretty good for a small engine -- 5hp.

[a64pilot]

There are lots of Diesel aircraft engines coming online, it's common rail more than anything that makes it possible, they are running I believe at about 2 lbs per HP, which ain't bad at all. Of course this is just pure engine weight, no accessories, gearboxes or I'm sure cooling systems, still .5 HP per lb isn't shoddy, and aircraft engines are unlike automobile engines in that they are usually meant to maintain that power output for considerable times, where a high HP auto engine usually only for seconds at a time.

The day of the spark ignition engine may be coming to an end, common rail has transformed Diesels, they are not our Grandfathers Diesels anymore.

I assume though that gasoline will be around for a long time with all infrastructure in place and I do not know if you can get more gasoline or Diesel out of a barrel of oil or if it's one or the other either, it may be both?


The Holy grail of aircraft engines for WWII that I don't think was ever reached was 1 HP, per Cu In and lb, and that is with incredibly high Octane fuel and turbo Supercharging etc.

[Dockhead]

Originally Posted by a64pilot

There are lots of Diesel aircraft engines coming online, it's common rail more than anything that makes it possible, they are running I believe at about 2 lbs per HP, which ain't bad at all. Of course this is just pure engine weight, no accessories, gearboxes or I'm sure cooling systems, still .5 HP per lb isn't shoddy, and aircraft engines are unlike automobile engines in that they are usually meant to maintain that power output for considerable times, where a high HP auto engine usually only for seconds at a time.

The day of the spark ignition engine may be coming to an end, common rail has transformed Diesels, they are not our Grandfathers Diesels anymore.

I assume though that gasoline will be around for a long time with all infrastructure in place and I do not know if you can get more gasoline or Diesel out of a barrel of oil or if it's one or the other either, it may be both?


The Holy grail of aircraft engines for WWII that I don't think was ever reached was 1 HP, per Cu In and lb, and that is with incredibly high Octane fuel and turbo Supercharging etc.

In my opinion, spark ignition engines still have a ways to go.

One thing which can really extend their lives is the Atkins cycle. Do you know anything about that? This brings their thermal efficiency almost to the level of the best diesels.

One thing which irritates me is all the hype around Elon Musk and Tesla, when all they've built is a glorified golf cart. Whereas Toyota, years earlier, did so much more revolutionary and really ground-breaking work, including even figuring out how to emulate the Atkins cycle using valve timing. If you haven't read about this, I highly recommend it -- fascinating stuff.

A true Atkins cycle engine could be something really cool. Would work for compression ignition engine too BTW, but not as much needed since diesels have much better expansion cycle with their greater compression ratios.


I'm not an expert on petroleum, but I know that gasoline used to be a waste product, so I doubt that we will stop using it. I don't know how much of those fractions can be converted to diesel fuel using cracking or whatever, but I bet the light fractions will need to be used in any case. So I think gasoline engines will probably be with us for a while. Note also that it's easier to burn gasoline in a clean way, than diesel fuel.

[John Holbrook]

Dockhead I think it was Toyota that built the glorified golf carts. Tesla have actual built exciting electric cars that enthusiasts often choose over other high performance sedans. Tesla also appears to be the catalyst that is forcing other car manufacturers like Porsche and Mercedes to introduce their own range of cars. All of this has and will drive far more acceptance and investment in electric vehicles than Toyota's endevours ever did.

Infinity is releasing car with a variable compression ratio engine next year.


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[GILow]

I keep hanging on for a reintroduction of a decent diesel outboard. There's a pocket cruise ship that visits South Australian waters from time to time and they are still using what I think are some 20 + hp Yamaha diesel outboards on their shuttle boats. They sound very odd but appear to work well, and as far as I can tell must be over ten years old now.

[Dockhead]

Originally Posted by John Holbrook

Dockhead I think it was Toyota that built the glorified golf carts. Tesla have actual built exciting electric cars that enthusiasts often choose over other high performance sedans. Tesla also appears to be the catalyst that is forcing other car manufacturers like Porsche and Mercedes to introduce their own range of cars. All of this has and will drive far more acceptance and investment in electric vehicles than Toyota's endevours ever did.

Infinity is releasing car with a variable compression ratio engine next year.

With respect, I disagree! Tesla's cars are simple straight plug-in electric cars -- the same basic technology as a golf cart. The Toyota parallel hybrid is a vastly more complex technology, and what is really astonishing is that Toyota went so far as to even invent a new IC engine cycle.

Of course Tesla have sexy Lotus designed and built bodies (Roadster) and plenty of flash; nothing like the frumpy Prius. But Tesla's sexy bodies cover relatively simple technology.

You have to take your hat off to Tesla's business model -- using tech industry paradigms and releasing the high end, low volume stuff first, skimming the cream and working their way down to the more complex mass market stuff later. With lots and lots and lots of hype, marketing, and PR.

But for pure technology, what they've done is far less impressive than what Toyota has done. Notwithstanding the false impression Tesla have created in the public mind with all the hype.

[a64pilot]

Originally Posted by Dockhead

In my opinion, spark ignition engines still have a ways to go.

One thing which can really extend their lives is the Atkins cycle. Do you know anything about that? This brings their thermal efficiency almost to the level of the best diesels.

Its Atkinson cycle actually, and yes I know a little about it, I have posted about it several times, its at the heart of why a Hybrid automoboile (works) and is now being used in non hybrids like Mazda's "skyactive". I hate marketing names but it is not specific to spark ignition engines, in fact I believe due to the direct injection of a Diesel, a Diesel may be better suited to it. Ne reversion of fuel back into the intake track like a spark ignition engine.

https://en.wikipedia.org/wiki/Atkinson_cycle

[a64pilot]

Originally Posted by Dockhead

and what is really astonishing is that Toyota went so far as to even invent a new IC engine cycle.

No they didn't actually, I believe the Atkinson cycle engine has been around for more than 100 yrs, just wasn't very usable due to it has almost no torque, but couple it with an electric motor that can supply torque when necessary, and it become viable.
While I love the Prius, I've had one for over 6 yrs and 185,000 miles, I believe the vast majority of its breakthrough technology was actually done by GM.
That is heresy I know, but it's my belief as I had studied the Prius system pretty extensively as it fascinates me.

[a64pilot]

Originally Posted by GILow

I keep hanging on for a reintroduction of a decent diesel outboard. There's a pocket cruise ship that visits South Australian waters from time to time and they are still using what I think are some 20 + hp Yamaha diesel outboards on their shuttle boats. They sound very odd but appear to work well, and as far as I can tell must be over ten years old now.

I've never seen one, but I think Yanmar built Diesel outboards for a while.
http://yanmardieseloutboardmotors.com/yanmar/

[Dockhead]

Originally Posted by a64pilot

No they didn't actually, I believe the Atkinson cycle engine has been around for more than 100 yrs, just wasn't very usable due to it has almost no torque, but couple it with an electric motor that can supply torque when necessary, and it become viable.
While I love the Prius, I've had one for over 6 yrs and 185,000 miles, I believe the vast majority of its breakthrough technology was actually done by GM.
That is heresy I know, but it's my belief as I had studied the Prius system pretty extensively as it fascinates me.

Well, the Aktinson [thanks for the correction] cycle engine, the real one from 100 years ago, uses a complex geometry crank to get the longer expansion stroke.

What Toyota (or GM) did, which is brilliant, and which is a real technological breakthrough, was to emulate the effect of it using valve timing. They call it an "Atkinson cycle", but I think they are being very modest (the opposite of Musk's habit) -- it's really a completely new cycle which merely gives an effect similar to the Atkinson cycle. It's the first fundamentally different IC engine cycle put into mass production in my lifetime (Wankel preceded my birth). It's a tremendous achievement, a real, historically significant technological achievement, not a marketing coup, which is what the Tesla is.

[GILow]

Originally Posted by a64pilot

I've never seen one, but I think Yanmar built Diesel outboards for a while.
Yanmar Diesel Outboard Motors

Ah, yes, that's the engine. Oops, I thought they were Yamaha.

They make a really odd sound... like a petrol engine at full throttle with badly retarded timing. I've seen them pushing very big centre console RIBs with maybe 10 people on board, and they get up on the plane very quickly.

[John Holbrook]

Originally Posted by Dockhead

With respect, I disagree! Tesla's cars are simple straight plug-in electric cars -- the same basic technology as a golf cart. The Toyota parallel hybrid is a vastly more complex technology, and what is really astonishing is that Toyota went so far as to even invent a new IC engine cycle.



Of course Tesla have sexy Lotus designed and built bodies (Roadster) and plenty of flash; nothing like the frumpy Prius. But Tesla's sexy bodies cover relatively simple technology.



You have to take your hat off to Tesla's business model -- using tech industry paradigms and releasing the high end, low volume stuff first, skimming the cream and working their way down to the more complex mass market stuff later. With lots and lots and lots of hype, marketing, and PR.



But for pure technology, what they've done is far less impressive than what Toyota has done. Notwithstanding the false impression Tesla have created in the public mind with all the hype.

I think you will find that Toyota and Japanese industry have invented very little in the automotive industry. Their culture bound by strong social protocols does not foster new approaches or free thinking. Most innovation in the automotive industry comes from the USA or Europe. What the Japanese do well is build low to mid range quality vehicles. They struggle to be successful in high range vehicles because their cars are comparatively boring and or unattractive.

Yes Tesla did have a Lotus based Roadster up until 2012. You should checkout the cars they make now. You say Tesla technology is simple yet their P95D sedan can drag off Ferraris (0-60mph in 3.2 seconds) and has a 250 mile plus range. Sometimes simple is the best. Tesla put enough battery in their cars so they don't need a backup IC engine to achieve a good range. Tesla has been a big player in advancing battery technology whereas Toyota just tackled the problem of range by adding an IC engine, a complex band aid solution.

I see the Prius as marketing hype... this car could have performed a lot better given Toyota's 80 years vs the Telsa's 13 years.





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