New Super Efficient Rotary Engine

[zboss]

Maybe a good engine for a dinghy?

Crazy-Efficient Rotary Engine Lands Million-Dollar DARPA Contract

[btrayfors]

I want one!

Not just for the dingy. They're gonna produce boat engines, including the current 40hp diesel-equivalent 50lb model (when in production).

Bill

[zboss]

Originally Posted by btrayfors

I want one!

Not just for the dingy. They're gonna produce boat engines, including the current 40hp diesel-equivalent 50lb model (when in production).

Bill

Seriously... can you imagine a diesel engine the size of an electric one with the same horsepower as we have now? It would completely upend the industry.

I'm betting it would be price competitive too because of so few moving and actual parts that are much smaller and easier to manufacture.

No water cooling system! If you DO need to cool you can inject water right into the combustion chamber... which only has the effect of increasing power. This is crazy.

[UNCIVILIZED]

Don't hold your breath waiting, a million dollar contract is like pocket change to them. Plus, most of what they do either doesn't pan out, or never sees the light of day.

Also, standard rotary engines are gas HOGs. 18mpg was Good mileage in my RX-7, & it literally got the same mileage at 20mph, 60mph, & 115mph. And we're talking about a 1.3l displacement engine here.
So, they've got their work cut out for them! In terms of refining the concept.

[captain58sailin]

Well 18 mpg @ 115 mph sounds good to me, you should only drive that speed so you get the most for your gallon of gas. With a standard piston engine (302) I get about 17 mpg @ 55 mph, of course it is a van big enough to live in, but it won't pick up girls like an RX-7.

[UNCIVILIZED]

Originally Posted by captain58sailin

Well 18 mpg @ 115 mph sounds good to me, you should only drive that speed so you get the most for your gallon of gas. With a standard piston engine (302) I get about 17 mpg @ 55 mph, of course it is a van big enough to live in, but it won't pick up girls like an RX-7.

Believe me, I did drive like that it like that! I had Navy schools all over the country for 1 1/2yrs, ergo, plenty of miles @ speed. And more or less, I lived out of it, but not in it. USN paid for both ;-)
Great car, nary a mechanical trouble, & only routine expenses.

[Badsanta]

Hope it works. It would be a game changer.

Sent from my SM-G860P using Cruisers Sailing Forum mobile app

[Seymore]

I remember reading that the weakness of rotary engines was the seals, the equivalent of the piston rings. The seals wore out too fast to make them feasible. Can anyone comment?

[zboss]

Originally Posted by Seymore

I remember reading that the weakness of rotary engines was the seals, the equivalent of the piston rings. The seals wore out too fast to make them feasible. Can anyone comment?

Apparently, there are no seals on this engine. 13 total parts and only two moving parts.

[Uncle Bob]

Originally Posted by zboss

Maybe a good engine for a dinghy?

Crazy-Efficient Rotary Engine Lands Million-Dollar DARPA Contract

Kind of reminds me of the Sarich orbital engine.

[senormechanico]

Wankel revisited. yawn

[newhaul]

I have one sitting here called the model 64 wankel ski drive brand new built in 1967 never even had crankcase oil in it 45 HP and the water pump is just to provide for wet exhaust looks similar to a sail drive weighs under 50 pounds and has 48 HP

[captain58sailin]

I think Sears put out a wankle engine snow mobile back in the late 60s, early 70s. They weren't much in the power part of the equation.

[TacomaSailor]

I bought a Mazda RX-2 (Wankel powered) new in 1972...and put 5-new engines into it until I sold it in 1981. The seals were dreadful. I suppose the newer Wankels have much better seals BUT, each time the Mazda dealer sold me a new engine (first three were warranties where I paid $0) he promised me the seal problem was solved.

My big question is WHY, if the seal problems were resolved in 1980, and they are such fantastic engines for reliability and power-to-weight ratios, no one except Mazda was marketing them.

If Wankels are the answer - why aren't they common now, 35-years after they solved all the problems?

I love the Wankel and do hope it becomes a common engine but I am sceptical.

[Cormorant]

Here's a bit from LiquidPiston's web page, describing their history. As with other promising technology (graphene-based watermakers!), I wonder what's taking so long. If they have patents protecting their inventions, and have working prototypes, it seems they could license the tech to many various manufacturers and change the world. I suppose they're just working out all the bugs and optimizing things, while locking down any remaining intellectual property before going big.

About Us | LiquidPiston
History

2015

Developing the power-dense, near-zero vibration, quiet X Mini, 70cc gasoline powered rotary four-stroke engine.
2012

Built working, firing 70 and 40 HP diesel engines, model “X,” that demonstrated the capability of engine architecture and thermodynamic cycle
2011

Invented and designed a new engine architecture, model "X," that embodies the HEHC cycle
2010

Built firing 20 HP diesel engine prototype, and what may be the world’s first naturally-aspirated rotary diesel engine
2007

Received small business innovation research (SBIR) grant from Army
Received first venture funding. Key investors include: Northwater Capital and Adams Capital Management
2004

Awarded top three winner prize in MIT’s entrepreneurship business plan competition (now called the $100K entrepreneurship competition)
2003

Dr. Nikolay Shkolnik and Dr. Alexander Shkolnik invented the innovative HEHC thermodynamic cycle and initial engine designs that embody the cycle