After a lifetime of making racecars go faster, Bruce Crower's new engine uses steam to squeeze more mileage from gas

How it Works After the first four conventional strokes, water is injected into the cylinder, creating steam to drive a fifth stroke for extra power. The last stroke recycles the steam water. Bruce Crower

How do you prevent insurgents from shooting down choppers? How do you keep a cast from itching? How do you reinvent the brick? You sketch. And then you work: nights, weekends-for years, if you have to. You blow all your money, then beg for more. You build prototypes, and when they fail, you build more. Why? Because inventing is about solving problems, and not stopping until your solution becomes real.

We're currently rolling out the winners of the 2007 PopSci Invention Awards. We'll be doling out a new innovation each day, so keep checking back for more of what the world's brightest inventors are currently cooking up. And if you just can't wait, pick up a copy of the June issue that just hit the stands.-Eds.

Name: Steam-o-Lene Engine

Inventor: Bruce Crower

Cost to Develop:
$1,000

Time: 1.5 years

Prototype | | | | |
Product


Bruce Crower's Southern California auto-racing parts shop is a temple for racecar mechanics. Here's the flat eight-cylinder Indycar engine that won him the 1977 Louis Schwitzer Award for racecar design. There's the Mercedes five-cylinder engine he converted into a squealing supercharged two-stroke, just "to see what it would sound like," says the now half-deaf 77-year-old self-taught engineer.

Crower has spent a lifetime eking more power out of every drop of fuel to make cars go faster. Now he's using the same approach to make them go farther, with a radical six-stroke engine that tops off the familiar four-stroke internal-combustion process with two extra strokes of old-fashioned steam power.

A typical engine wastes three quarters of its energy as heat. Crower's prototype, the single-cylinder diesel eight-horsepower Steam-o-Lene engine, uses that heat to make steam and recapture some of the lost energy. It runs like a conventional four-stroke combustion engine through each of the typical up-and-down movements of the piston (intake, compression, power or combustion, exhaust). But just as the engine finishes its fourth stroke, water squirts into the cylinder, hitting surfaces as hot as 1,500

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7 Comments

I just started receiving Popular Science Magazine yesterday and coincidentally I was doing research on the 6-Stroke engine for my own interests and stumbled on this article. I am happy that Bruce is interested in discovering a better internal combustion engine but to give an award for an idea that is not original and actually been around for more than 87 Years!! In my research it took me less than 5 minutes to find more than 2 dozen patents going back to the 1920s. Leonard H. Dyer was the inventor and first to patent the Idea. There have been many adaptations all of which are readily available via the US Patent and Trademark WEB site, www.uspto.gov. I did a search using "Six-Stroke" and found enough information to keep a person reading for 3 months. Apparently Dan Carny needs to do a little background work before giving credit to just the latest person to re-invent an idea. By the way, I was NOT able to find any patent filing for Bruce Crower as of 03/13/2008.

max9 (not verified)

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It is disappointing to see this re- re- re-invention of an integral steam bottoming cycle getting an award, but then maybe we shouldn't expect more diligence of PopSci than of the Patent Office. So much for a careful search of prior art!

On the technical side, this scheme does have merit. Since the same cylinder is used for both internal combustion and steam generation/power extraction, the water that is injected can be the primary cylinder coolant; in other words, you can eliminate the cooling jacket or fins, which simplifies the engine castings immensely. Turning off the water injection system during cold starts in cold weather should speed warmup. Because there's a phase change involved, water/steam mass flow will be less than the coolant flow of an equivalent engine. The condenser can probably be made smaller than a radiator for the same engine would be.

On the debit side is the fact that most of the engine's waste heat goes out the exhaust, and this scheme recovers only what would have gone to the coolant. Still, you could look at this as an ultra-simple evaporative cooling system with some energy recovery as a bonus. Other problems that will have to be addressed are contamination of the lubricating oil with water, and contamination of the water/steam with combustion products. It's fairly easy to incorporate a water separator in the oil circuit, but it might be harder to ensure that steam reaching the condenser is clean - and that has to be done or the condenser will get foul very quickly and won't work any more. Also - and here I'm on slightly shaky ground because I haven't run numbers - I think the cylinder geometry - the effective expansion ratio - will waste a lot of the power in the newly-generated steam. On the good side, that should prevent any condensation in the cylinder, which might cause hydraulic lock.

I like to think of this system as an "entry level" integral steam system. The next step up - the Peterbilt version, if you like - would route the exhaust steam from the cylinder to an exhaust heat exchanger, which would act as a superheater. From there, it would drive a steam turbine that would drive accessory loads independent of the engine - air conditioner, alternator, hydraulic pump or whatever was needed - leaving the core engine free to provide all its shaft power to the wheels. This would recover much more energy and make better use of it (turbines can have a high expansion ratio). On the downside, the required condenser size would be larger. This might be a very good high-efficiency plant for locomotives and long-distance road haulers, where ample space is available.

Best to all,
Marc de Piolenc
Iligan City, Philippines

the link above to the "patent" is wrong.

It is NOT a Patent. It's only an APPLICATION for a DESIGN and METHOD being claimed as "invented." He may get the design patent, but that is patenting only the design of the engine. The only value would be in a method patent.

But since he is trying to claim an idea which has clearly been around for ages, all of the "claims" will be basically rejected. The fact that the application's prior art section is devoid of the true prior art will in the patent examiner's eyes show that the patent is very weak. You have to address the prior art and the patent doesn't.

Design patents are a joke. The method patent claims are ridiculous. He wasted his money filing unless he did so to scam some investors... then they've lost.

Better and easier to crack the H2 from from the water and inject it thru the air intake as a boost to the gasoline.



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