Bugger to push-start.
March 30, 2004 11:40 PM   Subscribe

The Biggest Engine in the World. It's freakin' enormous. 100 000hp... yet more fuel efficient than your car. This contrasts with the smallest Wankel rotary, smallest diesels, and the smallest gas turbine engines.
posted by five fresh fish (33 comments total) 1 user marked this as a favorite
Oh, damn, I forgot to include some very tiny, italicized text for the metawhingers. Oy, vey!

The pictures of the big engine are remarkable. It had never occurred to me to wonder how big a cruise ship's engine would have to be. Now I know: really, really, really gigantic. Boggles my brainz, it does.
posted by five fresh fish at 11:43 PM on March 30, 2004

Yeah, freaky photos of the giant engine, it's hard to believe it's real.

This photo looks like it's a fake photoshop thing, as if it is evidence of a weird fetish group that gets off on digitally shrunken men fondling engine parts. Ooooh, remove the camshaft....slowly.
posted by mathowie at 11:58 PM on March 30, 2004

What's this thing used for? The driveshaft of a cruise ship? Generating electricity? Running some other enormously huge machine? And the other question: Why? There must be alternatives...
posted by slacy at 12:18 AM on March 31, 2004

Didja notice the built-in ladders in that photo, Matt? You can climb inside the rocker panels.

Slacy: think Queen Mary 2. She's a cruise ship, bigger than big. Horizontal skyscraper. Not going to power that boat with your Mercury outboard...
posted by five fresh fish at 12:39 AM on March 31, 2004

I'm quite impressed with that miniature rotary engine! Can anyone out there explain why rotary engines aren't more popular, both in cars and in other uses? They seem to be to be a very smart, efficient design
posted by Jimbob at 2:02 AM on March 31, 2004

because they don't have a desperately long life before needing a costly rebuild. For some reason the figure 100,000 miles comes to mind. YMMV.
posted by twine42 at 2:32 AM on March 31, 2004

What's this thing used for?

(From the link) These engines were designed primarily for very large container ships. Ship owners like a single engine/single propeller design and the new generation of larger container ships needed a bigger engine to propel them.

There must be alternatives...

There are
posted by magullo at 2:32 AM on March 31, 2004

Not to mention nuclear
posted by magullo at 2:35 AM on March 31, 2004

That's pretty darn impressive when you consider that a WW II carrier, USS Enterprise (CV-6), could generate about 120,000 shp on four shafts combined. That's with the conventional boilers and steam turbines of the day, not with an "engine" in the sense that's used here.

On the other hand, though, this big paperweight is designed for efficiency and long-haul reliability rather than speed. The Big E had to be able to run up to 33 knots, and the hull this thing is going into is probably going to cruise at half that or less (think supertanker or cruise ship).
posted by alumshubby at 3:57 AM on March 31, 2004

The miniature wankel is very cool.. I like the idea of tiny combustion engines replacing batteries.

I've got a mental image of a mobile phone with tiny little rip-cord starter like an outboard.. heh.
posted by jiroczech at 4:30 AM on March 31, 2004

"as if it is evidence of a weird fetish group..."

Freud was right after all.
posted by Keyser Soze at 4:50 AM on March 31, 2004

Wow, FFF. That's a big motor. What's that bearing material ? - ceramic, I guess. And the weird connecting rod innovation ?...... Why the heck haven't people figured this one out before?

50% thermal efficiency - not bad from a conventional design. I really like the oil squirters built into the piston heads. I could have used those in my old air-cooled Volkswagens - which were always breaking down from excessive combustion chamber temperatures. Some people should have oil squirters built into their skulls, too.

But I have one complaint - where's the cylinder head?. I want to see the HEAD, man! - Two valves per cylinder? Four? Eight? Sixteen? Does it even have valves?

And - if it has valves - are they sodium filled? My Volvo has sodium filled valves. Aircooled Porsches use 'em too.
posted by troutfishing at 5:10 AM on March 31, 2004

What weight oil does it use? .....and what about the oil filter? Does it require an oil filter wrench with a handle twenty feet long that takes thirty men to push?

And - spark plugs?

posted by troutfishing at 5:14 AM on March 31, 2004

Hey, I've never seen Metafilter do that before. It likes the big motor!
posted by troutfishing at 5:15 AM on March 31, 2004

Wow! That is sooo coooool! Thanks, fff!

I could have used those in my old air-cooled Volkswagens - which were always breaking down from excessive combustion chamber temperatures.
Looks like we had the same experiences, trout. My 68 Bug's engine died from lack of sufficient oil while driving down the freeway on a summer morning -- sounded like Thor was hammering inside the engine compartment.

And - spark plugs?
It's a diesel. No spark plugs. Don't get me (or Matt) started on the absolute coolness of diesels, specifically Volkswagen TDIs. I have one, and ... ah, I better not get started. Me like.
posted by Holden at 5:45 AM on March 31, 2004

Oh, damn, I forgot to include some very tiny, italicized text for the metawhingers. Oy, vey!

You forgot this.
posted by Civil_Disobedient at 6:10 AM on March 31, 2004

Heh heh... you said 'wankel'
posted by Robot Johnny at 6:19 AM on March 31, 2004

Whoa that's so Guinness World Record it hurts ! I wonder if there's any engine more efficient when it comes to power spent for each $ revenue.

On a tangent: I too love diesel cars and got one. Curiously (?) enough many people now agree with me, lotsa more diesel cars were sold and the price of diesel fuel now nearly matches unleaded price in my country ; the excuse by 7 sisters, I guess, is the usual demand/supply market dictate.

Have you noticed a massive increase in diesel fuel price too ?
posted by elpapacito at 6:24 AM on March 31, 2004

I wonder if these little engines can replace laptop batteries. I've read about the methanol powered laptop, but that's more of a high tech fuel cell than a running engine. I don't expect these little things to burn very clean or quietly though.
posted by skallas at 6:40 AM on March 31, 2004

Little Daddy, here in South Florida diesel prices are more volatile than prices for gasoline. Right now it's $1.999 a gallon, same as mid-grade gasoline. A month ago it was $1.659.
posted by Holden at 6:46 AM on March 31, 2004

Big engine! There's lots of big engine research going on right now. Companies always want more efficiency, but sulphur, nitrogen oxide (NOX), volatile organic (VOC) and particulate (PM10) emission regulations are also starting to bite in both the marine shipping and train sectors. These things usually run on very heavy oils, heavier even than motor oil because the fuel is so much cheaper. Diesels can be coaxed to run more cleanly, but at much higher cost.

Diesel and gas prices are linked more than they used to be. Improvements in refining allow the refiners to produce gas & diesel from the same feedstocks. If there's an oversupply of gas, they can make diesel instead and vice-versa. The diesel market is more volatile that it used to be because it's essentially the gas market too.

It's very difficult to get a Wankel engine to seal properly. Ask an RX-7 owner how many times they had their engine overhauled. New materials seem to be licking the problem, but for now Wankels are more expensive than piston engines.

Wankels are still a Carnot-like engine though, which means that their efficiency tops out at about 30%. The better choice for Prius-like hybrids, I've always thought is an electric car with a gas turbine generator. Turbines can be 40% to 50% efficient, much better than Carnot engines.
posted by bonehead at 7:22 AM on March 31, 2004

Most large engines are more efficient than our cars' engine. Sure diesel has something to do with it, but not completely. My friend has one of those Rock-n-roll super busses (like rock stars have). It gets 10 mpg! But it's HUGE. Compare that to a large SUV, most of them get just over 10, and this bus is a freaking bus.

cool link. thanks.
posted by tomplus2 at 7:22 AM on March 31, 2004

I wonder what the rpm is on that mother? That 12-cylinder engine -- how many times does each cylinder fire in a minute? The stroke is so huge -- it's mind-boggling.
posted by Holden at 7:49 AM on March 31, 2004

Oh, never mind -- 102 rpm. Seems so slow. 5 million foot-pounds of torque!
posted by Holden at 7:51 AM on March 31, 2004

Troutfishing: And the weird connecting rod innovation ?...... Why the heck haven't people figured this one out before?

Steam engines have been fitted with that bit of kit for a few hundred years. Everything old is new again.

If you are interested in more, I'd recommend 1800 mechanical movements and devices which is filled with all sorts of movements and designs from the turn of the century, theres even a riding lawn tractor/mower, which is steam powered of course. All we have really done since then is improve the existing ideas.
posted by Pink Fuzzy Bunny at 7:53 AM on March 31, 2004

Can anyone out there explain why rotary engines aren't more popular, both in cars and in other uses?

They're particularly brutal on seals, but a seal job on the last RX-7 (an awesome and unappreciated machine) fell in price to $1,000. For a high-performance car, that's not a bad pricetag if it indeed happens after 75-100k miles.

Getting the timing and the lambda right is vitally important on a Wankel, since they do not forgive knocking as well as a standard reciprocating engine.
posted by trharlan at 8:09 AM on March 31, 2004

Wankels have a unique problem in that their efficiencies don't exactly compute when compared to reciprocating engines.

For example, they are typically LESS efficient on a energy/BTU basis. However, they have a much higher power to weight ratio. In general, you will feed a Wankel a little more gas to get a little more power in a smaller and lighter package. The largest knock against Wankel engines have always been the wear on the wiper seals at the tips of the rotors.

Most manufacturers can't resist the lure of cubic inches... they go ahead and install a Wankel that displaces far more than necessary to get the job done. ("What the.... no, I don't want a car with only 800ccs! Give me a bigger engine!)

BTW - Magullo - THANK YOU for the link to the nuclear powered ship! I'm in the nuclear industry, and I never new that we had a nuclear commercial ship. Most excellent!
posted by insulglass at 9:31 AM on March 31, 2004


So, that is a big one. Suck on that Isambard Kingdom Brunel.
posted by asok at 9:42 AM on March 31, 2004

102rpm. Sheezus. It's be like a heartbeat. Lots of motorcycle engines redline at 14 000rpm. F1 racecars get nearly 20 000rpm. Turbines often spin upwards of 100 000rpm.

That's two and three orders of magnitude difference. Yeesh.

Minature gas turbine driving a generator driving electric motors in each wheel? That'd be cool. Especially on a motorcycle...
posted by five fresh fish at 10:02 AM on March 31, 2004

I've got a wankel engine in my RX-8, as far as efficient goes it is a very powerful engine. About 238 hp from a 1.3l engine. However fuel efficient it is not, I get about 15 - 16 MPG, which is not very cheap these days in Europe.

Biggest problem with the rotary is switching it off while still cold, next time you start it there's a big change you flood your engine and the car has to be towed. Oh the joys of an expensive sportscar.

Still great to drive though, and I think the Renesis wankel engine will turn out to be quite durable in the end.
posted by sebas at 11:20 AM on March 31, 2004

bonehead: Carnot cycle efficiency is the theoretical maximum for any heat engine be it steam, gas turbine, or internal combustion. The only way to circumvent that is to go to direct conversion devices such as fuel cells, but those have enough problems of their own.

Even at large (power plant) scales, gas turbines are just starting to break 40% efficiency (GE claims 46% for it's 100 MW LMS100 turbine). Smaller gas turbines are much more likely to be in the 30% range.
posted by yarmond at 12:34 PM on March 31, 2004

I have an RX8 too and haven't had any issues with the cold flood, quick blip of the trottle as you turn it off is meant to completely eliminate it but I've never even bothered with that.
posted by zeoslap at 1:21 PM on March 31, 2004

Even at large (power plant) scales, gas turbines are just starting to break 40% efficiency...

Lots of ships use gas-turbine engines nowadays. If it sounds exotic to you, think of a very large jet engine only without the jet plane. Multiple gas turbines can combine their power via reduction gearboxes too.

I would like to see how efficiently a gas-turbine-powered ULCC (ultralarge crude carrier, a really big oil tanker) could cruise.
posted by alumshubby at 3:57 PM on March 31, 2004

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