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6 Stroke Engine

New 04/19/2006, updated 04/20/2006


Ed Note: I know full well that this has absolutely less than nothing to do with GIII SHO's. But as I read it, I just had to give a man that is 75 years old his due for still having the burning desire to build a better mousetrap. My posting this has less to do with the engineering of a 6 stroke, hell I don't understand it completely, but rather the man himself. Bravo Sir!
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Good read, long, but good.

Roman

Under the hood of almost all modern automobiles there sits a four-stroke internal combustion engine (ICE). Though the efficiency of the design has been improved upon significantly in the intervening years, the basic concept is the same today as that used by the first practical four-stroke engine built in the 1870s. During every cycle in a typical car engine, each piston moves up and down twice in the chamber, resulting in four total strokes… one of which is the power stroke that provides the torque to move the vehicle. But the automotive industry may soon be revolutionized by a new six-stroke design which adds a second power stroke, resulting in a much more efficient and less polluting alternative.

OMITED(how a 4 stroke works)

The clever new six-stroke design was developed by 75-year-old mechanic and tinkerer Bruce Crower, a veteran of the racing industry and a the owner of a company which produces high-performance cams and other engine parts. He had long been trying to devise a way to harness the waste heat energy of combustion engines, and one day in 2004 he awoke with an idea which he immediately set to work designing and machining. He modified a single-cylinder engine on his workbench to use the new design, and after fabricating the parts and assembling the powerplant, he poured in some gas and yanked the starter rope. His prototype worked.

His addition to the ICE design is simple in principle, yet a stroke of genius. After the exhaust cycles out of the chamber, rather than squirting more fuel and air into the chamber, his design injects ordinary water. Inside the extremely hot chamber, the water immediately turns to steam– expanding to 1600 times its volume– which forces the piston down for a second power stroke. Another exhaust cycle pushes the steam out of the chamber, and then the six-stroke cycle begins again.

From the Autoweek article:

Crower invites us to imagine a car or truck (he speaks of a Bonneville streamliner, too) free of a radiator and its associated air ducting, fan, plumbing, coolant weight, etc.

"Especially an 18-wheeler, they've got that massive radiator that weighs 800, 1000 pounds. Not necessary," he asserts. "In those big trucks, they look at payload as their bread and butter. If you get 1000 lb. or more off the truck…"
Offsetting that, of course, would be the need to carry large quantities of water, and water is heavier than gasoline or diesel oil. Preliminary estimates suggest a Crower cycle engine will use roughly as many gallons of water as fuel.

And Crower feels the water should be distilled, to prevent deposits inside the system, so a supply infrastructure will have to be created.

Bruce Crower holds a patent on the new design– which he is still developing and tweaking– but he estimates that eventually his six-stroke engine could improve a typical engine's fuel consumption by as much as forty percent.


More:

Bruce Crower has lived, breathed and built hot engines his whole life. Now he's working on a cool one—one that harnesses normally-wasted heat energy by creating steam inside the combustion chamber, and using it to boost the engine's power output and also to control its temperature.

"I've been trying to think how to capture radiator losses for over 30 years," explains the veteran camshaft grinder and race engine builder. "One morning about 18 months ago I woke up, like from a dream, and I knew immediately that I had the answer."

Hurrying to his comprehensively-equipped home workshop in the rural hills outside San Diego, he began drawing and machining parts, and installing them in a highly modified, single-cylinder industrial powerplant, a 12-hp diesel he converted to use gasoline. He bolted that to a test frame, poured equal amounts of fuel and water into twin tanks, and pulled the starter-rope.

"My first reaction was, 'Gulp! It runs!'" the 75-year-old inventor remembers. "And then this 'snow' started falling on me. I thought, 'What hath God wrought…'"

The "snow" was flakes of white paint blasted from the ceiling by the powerful pulses of exhaust gas and steam emitted from the open exhaust stack, which pointed straight up.

Over the following year Crower undertook a methodical development program, in particular trying out numerous variations in camshaft profiles and timing as he narrowed the operating parameters of his patented six-stroke cycle.

Recently he's been trying variations of the double-lobe exhaust cams to delay and even eliminate the opening of the exhaust valve after the first power stroke, to "recompress" the combustion gasses and thus increase the force of the steam-stroke.

The engine has yet to operate against a load on a dyno, but his testing to date encourages Crower to expect that once he gets hard numbers, the engine will show normal levels of power on substantially less fuel, and without overheating.

"It'll run for an hour and you can literally put your hand on it. It's warm, yeah, but it's not scorching hot. Any conventional engine running without a water jacket or fins, you couldn't do that."

Indeed, the test unit has no external cooling system—no water jacket, no water pump, no radiator; nothing. It does retain fins because it came with them, but Crower indicates the engine would be more efficient if he took the trouble to grind them off. He has discarded the original cooling fan.

So far he has used only gasoline, but Bruce believes a diesel-fueled test engine he is now constructing—with a hand-made billet head incorporating the one-third-speed camshaft—will realize the true potential of his concept.


But the inventor sees overriding benefits. "Can you imagine how much fuel goes into radiator losses every day in America? A good spark-ignition engine is about 24 percent efficient; ie., about 24 cents of your gasoline dollar ends up in power. The rest goes out in heat loss through the exhaust or radiator, and in driving the water pump and the fan and other friction losses.

"A good diesel is about 30 percent efficient, a good turbo diesel about 33 percent. But you still have radiators and heavy components, and fan losses are extremely high on a big diesel truck."

Bottom-line, Bruce estimates his new operating cycle could improve a typical engine's fuel consumption by 40 percent. He also anticipates that exhaust emissions may be greatly reduced. It's all thanks to the steam.

"A lot of people don't know that water expands 1600 times when it goes from liquid into steam. Sixteen hundred! This is why steam power is so good. But it's dangerous…"

The danger of a boiler explosion has long been a factor in engineering—and in operating—steam powerplants of all kinds, and Crower is properly wary of the miniature boiler he has conjured up inside his test engine. That's one reason he chose to use one originally manufactured as a diesel, for its inherent strength, though he installed a carburetor and ignition system so it could burn gasoline at first.

The original diesel fuel injector system now supplies the water spray to generate the steam-stroke.

In addition to producing extra power, the injected water cools the piston and exhaust valve, which suggests to Crower that he could raise the compression ratio. "I've done this many times on regular engines: 15-to-1 on gasoline for the first five seconds works pretty good until you get some chamber heat and then suddenly it gets into pinging. But with the chamber being chilled, I bet 12-, 13-to-1 will be no problem on cheap fuel.

"So what we can maybe do is have fuels that aren't quite as good…It'll save a nickel a gallon not having to keep three grades going."

As for his hope of lowering emissions, Bruce speculates the steam might purge "cling-on hydrocarbons" out of the combustion chamber. "This thing may turn out to be so clean that you won't have to have a catalytic converter.

But he admits that's unknown, saying "there's a lot of experimenting still to be done." Which prospect makes him smile. He thrives on this kind of challenge.
Bruce's Background
"You've kinda got to be in the cam business and know the dynamics of engines," Bruce Crower says about how the idea occurred to him. And he certainly has that background.

He was building and racing hot rods (and hot bikes), manufacturing speed equipment and operating his own speed shop in his home town of Phoenix when he was still a teen.

After moving to San Diego in the 1950s, among other exploits he dropped a Hemi into a Hudson and drove it to a 157-mph speed record at Bonneville.

Inevitably, the inventive and inexhaustible Crower built up a major equipment business in superchargers, intake manifolds, clutches and, especially, camshafts. He's also credited with first suggesting a rear wing to Don Garlits—in 1963, three years before Jim Hall's winged Chaparral. Bruce Crower is now in Florida's Drag Racing Hall of Fame.

Crower actually had introduced a wing two years earlier, during practice on Jim Rathmann's 1961 Indianapolis car—five years before Jim Hall's winged Chaparral. Bruce had been crewing at the Speedway since 1954 (Jimmy Bryan, second place), and had been part of Rathmann's 1960 victory effort. He was likewise on the winning teams in 1966 (Graham Hill) and 1967 (AJ Foyt). Three decades later, in 1998, Eddie Cheerer won with Crower cams.

OMITED - (Some personl info)

One of several projects is building up Honda S2000 engines for the Midget raced by his granddaughter, Ashley Swanson. ("I think she's on par with Danica Patrick," says the proud grampa.)

Then he adds philosophically, "If it turns out to be great, fine. If it doesn't, it's just another year out of my life that I've had a lot of fun doing something."
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Whoa.




IT_____________COULD______________WORK ! ! ! ! ! ! ! !
Eric Lehmann
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There's a really cool .avi or something like that out there on the web
somewhere. saw it a couple years ago. i don't think this is the only
guy tinkering with it

Matt K
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One of the auto rags had an article a couple months ago about how BMW was taking exhaust heat and using it to make steam to assist...

http://www.popsci.com/popsci/automotivetech/163cf51b6fd89010vgnvcm1000004eecbccdrcrd.html  

There is a lot of energy wasted by combustion that is for sure.

Scott
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I agree! I like that he is trying to help the environment, automotive industry and general public and not just trying to make a quick buck.
Roman
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I had a slow leak to the combustion chamber through the head gasket on one cylinder of a Chrysler 2.2 Turbo engine. 

It got great gas mileage (1.5 times normal) until I got through my last final that semester and had a chance to change the head gasket. It was about three weeks, IIRC. Gas mileage was both by indicator and checking miles against gallons to fill tank.

That cylinder was clean as a whistle, too.

Best Regards,
Doug
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Anybody on this site old enough besides me to remember when Iskenderian used to advertise "5 Cycle cams" an one of his competitors used a cartoon of a clown on a bicycle to ridicule his ads. Hot Rod magazine in the late 50's or early 60's carried these ads.
Zero 97TR
Pottsville, Pa.
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Ed Note: I'm quite sure I'm a wee bit older that you Zero, and I remember that if you didn't have an Isky, well just park it.
U.L.
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04/20/06

The physics seams sound other then how much pressure and the timing to inject the water. I am imaging that to do this where the now wasted exhaust heat would turn injected (?) water to steam you would have to not eject the hot gasses on the standard exhaust stroke but rather inject the water just as the piston reaches TDC on the now dead return stroke just like a standard compression stroke, then the injected water could cause the second power stroke, though I am having a hard time understanding how this steam stroke would be sufficient enough to cool an air-cooled motor to the point of being able to hold your hand on it. Of course the other issue is that instead of injecting the water maybe he is using at as a older design steam engine would by having a chamber to collect the steam inject it into the cylinder on a now alternating power stroke to force the piston down. Interesting what old guys can come up with when their brains are supposed to be just losing usable cells, eh?
Carter
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04/20/2006

I almost forgot that part! We took it down off the lift then started it up, put it in reverse and promptly went straight forward running over a Snap-On roll-away that had just been given to the shop the week before. After straightening out the nose and replacing the front bumpers it took us a week to figure out how to correctly flip that ring gear. 

I remember seeing a car magazine, probably R & T back in the '70's that had a 912 Porsche with a 455 Buick mounted in it using the Toronado drive train and an ingenious set of luggage bolted or fiberglassed together from the inside and insulated to cover the engine in the back seat. Real luggage space up front was nearly completely eliminated due to the radiator and fans of the era. The rear space was marginal. One of my favorite swaps other then the 3.3 liter 911 engine in a 356.
Carter
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0420/06

The stock-looking engine comment caught my eye.

Back in the '70s, my buddy bought a new 304 2bbl 3-speed '72 Gremlin. The
next year, we installed an AMX 343 that I had in my garage from my '68 AMX.
Since AMC used Ford Autolite carbs (Holley bolt pattern), going from the
2bbl to the 4bbl let us use the stock fuel line and air cleaner (plus the
engines looked the same).

We went to the AMC Drag Day (sponsored by AMC...our employer at the time) at
Milan Dragway. The Gremlin got placed in N-Stock, since it looked stock, and
Milan used the fuel line as their checkpoint for a stock setup. The car ran
14.80s, which was a good two seconds better than all but one other N-Stock
car. The other N-Stock car that was quick was supposed to be a 283 Impala,
but the owner obviously played the same game and had a healthy bigger
small-block in there. Ed ran the other cheater in the N-Stock final, after
both cars blew away everyone else n the class, and won!!

We then put a blueprinted stock 401 with Hooker headers and a new 4-speed in
the next year (1974) and the car ran low 14s, smoking the tires through the
first two gears. It would have been easy mid-low 13s if we had good tires,
but we used stock tires as the 'weakest link" to save the stock clutch,
u-joints, and rear end (still the old AMC setup with the axle keys).

Ron Porter


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