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Old 17-05-2015, 10:43   #31
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Re: New Super Efficient Rotary Engine

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Originally Posted by UNCIVILIZED View Post
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.
I agree. Rotary engines also had to (inject oil?) to lubricate the apex seals, and they were still a high wear item.

I'd be more interested in Yanmar getting into the 6 stroke diesel engine technology. It's basically the same as a 4 stroke engine, but there is a water injector, the cam is redesigned and there is a water intake stroke and power stroke at the end. This vaporizes the water to steam, pulls a ton of heat out of the combustion chamber, gives you 2 power strokes per cycles instead of 1, gives you 1/3 power strokes instead of 1/4, drastically increases fuel efficiency, especially with turbodiesels, can eliminate or drastically reduce the cooling system, makes the combustion chamber much cooler for the next intake stroke and helps spin up the turbo for more boost from the steam.

Inside Bruce Crowers Six-Stroke Engine | Autoweek
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Old 17-05-2015, 12:58   #32
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Re: New Super Efficient Rotary Engine

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Originally Posted by med View Post
No mention about end seals in there.
You can read the contents in it's entirety by clicking on the link on the right hand panel of the web page. The author's technical paper is all about destructive heat buildup and mentions seals (in a general sense), among the myriad other things where unwanted heat buildup reduces the life expectancy of Wankels and in particular the single rotor variety military UAV Wankel motors that are deemed unflightworthy after the 3rd rebuild. Less than a 1000 hours duty and then tossing into the scrap heap doesn't sit well for a thrifty guy like me. I like the idea of rotary engines in small gensets for a bunch of reasons. If it can run on diesel, so much the better. They just need a little innovation now and then.
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Old 17-05-2015, 13:25   #33
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Re: New Super Efficient Rotary Engine

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I wouldn't actually say the large wankel market is exactly dead Mazda was still producing them for cars as late as the 2012 model year in the rx8 and they say if theycould sell 100 k units a year they would continue to produce it.
If you believe Mazda corporate the Wankel's gone back to the drawing board and will re-emerge as a range extender for their future hybrid car market. It'll be NOT reborn to propel another RX magnet to attract chicks, but tamed to placate the eco-consious hybrid van soccer Moms that they became!

Now, if LiquidPiston makes good on their promises on a diesel rotary with low end grunt and gets a Kohler or Perkins or Cummins to come along and kick this thing through the goal posts then that would suit me to a T.

But this new rotary has been in development for years.

I'm not holding my breath.
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Old 17-05-2015, 13:34   #34
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Re: New Super Efficient Rotary Engine

There is a 4 letter acronym that fits perfectly to this scenario

KISS

Keep It Simple Stupid.

The 4 stroke diesel fits this perfectly. It is known tech, it works and in it's most basic format (as used in most sea going vessels) it can't get more simple. Suck, Squeeze, Bang and Blow!

If rotary engines are so great how come only Mazda have ever used them in road cars and then only in the RX series? The other thing that kills them is the total loss lubrication system. Fine if on land where you can stop off at a service station and top up the lubrication but imagine if you are a couple of hundred miles offshore when the lube warning light comes on!

Like many new engine ideas I'll believe it when I see 100s of thousands of units in use. The simple infernal combustion engine (petrol and diesel) has many billions of miles under it's belt and is proven technology. Besides unless you are running an F1 Offshore Powerboat do you really need all that power? 40 HP is more than enough to move my 40footer at 7 kts against the wind and tide.

Keiron
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Old 17-05-2015, 13:35   #35
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Re: New Super Efficient Rotary Engine

A really compact, powerful engine that they use in torpedos is the swashplate engine. They are a 5 or 6 cylinder axial engine. They've been used in torpedoes for decades, but recently Duke is touting a version of it as their own design. Very few parts, very lightweight and powerful. Cooling the block is a bit tricky. The 21" dia. version in the mark 48 torpedo is reputed to produce about 600hp.

A very small version could fit in a 5hp outboard housing, but producing 100hp or so. The gas version can be run at up to 14:1 CR which gives it better fuel efficiency, I bet a diesel version could be even higher than a normal diesel for improved economy over a regular diesel, not ot mention reduced parts count and lighter weight.

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Old 17-05-2015, 13:54   #36
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Re: New Super Efficient Rotary Engine

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There is a 4 letter acronym that fits perfectly to this scenario

KISS
.....

If rotary engines are so great how come only Mazda have ever used them in road cars and then only in the RX series? The other thing that kills them is the total loss lubrication system. Fine if on land where you can stop off at a service station and top up the lubrication but imagine if you are a couple of hundred miles offshore when the lube warning light comes on!
Hmmm.... carry enough spare engine oil and dump the proper ratio in the remaining gas and carry on if it's a Wankel. I did this to my old Evinude V4 outboard and ****canned the oil injection bottle for good. At least now I'll run out of lubricating oil and gas at the same time!
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Old 17-05-2015, 14:09   #37
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Re: New Super Efficient Rotary Engine

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Originally Posted by socaldmax View Post
A really compact, powerful engine that they use in torpedos is the swashplate engine. They are a 5 or 6 cylinder axial engine. They've been used in torpedoes for decades, but recently Duke is touting a version of it as their own design. Very few parts, very lightweight and powerful. Cooling the block is a bit tricky. The 21" dia. version in the mark 48 torpedo is reputed to produce about 600hp.

A very small version could fit in a 5hp outboard housing, but producing 100hp or so. The gas version can be run at up to 14:1 CR which gives it better fuel efficiency, I bet a diesel version could be even higher than a normal diesel for improved economy over a regular diesel, not ot mention reduced parts count and lighter weight.
A Torpedo engine does not have to run for too long.
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Old 17-05-2015, 14:51   #38
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Re: New Super Efficient Rotary Engine

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Originally Posted by kas_1611 View Post
There is a 4 letter acronym that fits perfectly to this scenario

KISS

Keep It Simple Stupid.


If rotary engines are so great how come only Mazda have ever used them in road cars and then only in the RX series?
Keiron
Actually you are incorrect there were many companies that had production models with the rotary engine prior to Mazda.
Amongst them were Alfa Romeo, American Motors, Citroen, Ford, General Motors, Mercedes-Benz, Nissan, Porsche, Rolls-Royce, Suzuki, and Toyota
Rolls even made a 2stage diesel version
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