Posted on 09/14/2007 9:15:09 AM PDT by Uncledave
By PETE LYONS
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.
Potential…and Questions 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. (He uses rainwater in his testing.) Keeping the water from freezing will be another challenge.
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 Cheever won with Crower cams.
Bruce even produced his own complete Indy engine, a flat-8 that didn’t quite make the field in 1977 and then was rendered obsolete (due to its width) by the advent of ground-effect tunnels. But the Crower 8 and its automatic clutch did win an SAE award for innovation.
Today, Crower Cams and Equipment Company employs about 160 people in five facilities, and manufactures not only cams but crankshafts and connecting rods—including titanium rods for (unnamed) Formula One customers.
Bruce Crower can’t be called retired now, but he’s happy to let the company he founded “roll along” while he “plays with cars.” That’s how he looks at the intensive R&D work he carries out in the privacy of his 13-acre horse property near the rural community of Jamul.
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.)
But his prime focus is proving his six-stroke engine is as revolutionary as he believes it is. “I’ve been trying to find something wrong with the whole basic idea for almost a year,” he says, “but I think we’re going to have a very marketable item.”
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.”
Water injection has been used in the past to boost power. Check out late WWII aircraft. It increased compression and cooled the engine. It was not, however, injected in a separate cycle.
Water injection has been used in the past to boost power. Check out late WWII aircraft. It increased compression and cooled the engine. It was not, however, injected in a separate cycle.
A steam-stroke??
Just call me Rusty....Rusty Shackleford.
Let us know when the perpetual motion engine is completed.
There is a patent for a magnetic motor that has 1200 watt output with no visible input. That never got off of the ground either.
The T-56-10W Allison turboprop on the early P-3s and C-130s used water injection to provide extra power for takeoff. Water injection was abandoned on the subsequent T-56-14, which develops more HP without water. Water injection has traditionally been a stopgap until a better design was achieved.
It's all been looked at 10000 times before
Some good points some bad points
Cycle guys go crazy looking at this
In the end, usual systems level decision: cost/benefit/market decision
Don't do it unless killer app
Goes into engineering memory hole until somebody else dusts it off...
Hmmmm.....
Maybe we could put those “undocumented immigrants” to work.
Doing the jobs Americans won’t do and what not....
Duh. Glanced thru the article, started thru the comments until the name hit me. Of course, Crower Cams were a big part of rodding way back when cars were comparatively simple, and a hell of a lot more fun.
Wonder if air cooled designers wood be of any help with this engine. I loved VDubs and hated that the smog systems caused them to be water cooled, IMHO. Even motorcycle manufacturers are kneeling to the Green Gurus.
I sincerely hope we can stop this governMENTAL control and regain our individual freedoms again. Oh, well. It’s just a dream.
BTW, you're 100% correct about ethanol's anti-knock capability. However, neither does it produce the BTU's of gasoline.
In effect, one winds up with "High-Octane," low octane gasoline. Because you are displacing gasoline, you quickly reach a point at which efficiency suffers.
If he runs it as cool as he says he can, he might be able to avoid lubricants all together and use a teflon seal. Would have to get the engine temp below 350F
Yep, they sure were. Crower himself used to sell a water/alcohol injection system back in the '70s and '80s. Those rigs still command $500.00 or more on eBay.
What's your opinion on this?
Still, it shows that there is a lot of potential for making internal combustion engines more efficient.
Interestingly, this is a redesign of the top end of the engine, while another inventor (www.revetec.com/) has redesigned the bottom end. Virtually all piston engines have used essentially the same system for converting linear power into torque, for more than 100 years, but Revetec has a system that is inherently more efficient.
These two ideas could actually be used together to make a vastly more efficient engine (assuming that all the various details can be worked out). The Revetec guys are a bit further along. Some engines based on the Revetec concept are already being sold.
The world automobile industry has expended far, far, more effort for the last 40 percent improvement that has already been achieved.
Normally, an engine produces power with 1 stroke in 4. It does this by capturing the energy of expansion directly resulting from combustion.
This engine adds another power stroke, producing power with 2 strokes in 6. The second power stroke captures energy from the waste heat left in the cylinder by the combustion stroke, and it uses about the same amount of fuel, to produce these two power strokes, as it previously required for one.
Right after the steam power stroke.
“Also if I remember correctly some WWII aircraft engines used a
water injection system to cool the cylinders creating a denser
gas/air mixture that produced more power for short burst.”
Mentioned on a recent “Dogfights” episode on the P-47 Thunderbolt
on The History Channel’s “Dogfights”.
http://en.wikipedia.org/wiki/P-47_Thunderbolt
The main production P-47C subvariant was the P-47C-5 which introduced a
new whip antenna and the R-2800-59 engine with water-methanol
injection with a war emergency power rating of 2,300 horsepower (1,700 kW).
Engines can be built with metals that won't rust.
One of the many details that needs to be addressed to make this a practical technology. However, this engine will run much cooler than current internal combustion engines, allowing for the possible use of slippery surface materials in place of liquid lubricants.
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