Six cycle engine- really cool!

[Chapap]

I recently saw a video of this. I imagine that this is a 100 year old idea, but there's a fella somewhere who made one that runs. This is probably the coolest odd engine I've seen. It adds another power stroke after the exhaust stroke of a standard 4 stroke engine. it goes:
intake > compression > ignition > (partial?) exhaust > water injection, steam expansion > exhaust

Of course I can't find the video I watched, but that seems super cool. He said he has it running but that's about it. It takes about 50/50 fuel to water and the block stays cool enough to touch. If the goal is to turn heat into power, this seems like a genius idea. All it is is an extra valve and a slower cam. Besides the typical making it work, this also has water in the cylinder which is typically undesirable. The six cycle wikipedia article is not much help... I'd need to read a dozen more wiki articles to understand that article.

 

[superj]

i have never heard of something like that. google, here i come

 

[superj]

Inside Bruce Crowers Six-Stroke Engine (autoweek.com)

 

[Chapap]

Inside Bruce Crowers Six-Stroke Engine (autoweek.com)

LOL it wasn't a video I watched, it was this article. That's a bold statement to add 40% efficiency. I really like the quote at the end.

“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.”

 

[superj]

i wonder what happened with this. i couldn't really find any recent stuff on it. there was a few 2010 articles in engineering pages about how it works and then some lists of others who have also done single and two cylinder 6 stroke engines, but nothing really went to production.


kind of like the barrel engine design. maybe it was to good and the oil companies bought it out to keep oil "needed" as much as it is now?

 

[superj]

THE ALMEN A-4 WOBBLE-PLATE ENGINE: 1921

Left: The Almen aero engine: 1921 Eighteen horizontally-opposed cylinders in two sets of nine with a central wobble-plate; static barrel type. Water cooled. Rotary valve disc at each end of the engine. The A-4 was the fourth experimental barrel engine built by John O Almen of Seattle, Washington State, for testing at McCook Field, Ohio. The engine project began in 1921 and by the mid-1920s, the A-4 had passed its acceptance tests. Despite this success the Almen engine never went into production, because of a growing emphasis by the US Army Air Corps on air-cooled radial engines with large frontal area. European air forces generally preferred water cooled engines. Like other barrel engines, the Almen had a much smaller frontal area than other water-cooled engines of similar horsepower, promising reduced air resistance when installed in an aeroplane. It was rated at 425 hp but weighed only 749 pounds (a power/weight ratio of 1.76 lb/hp), a significant achievement for the time. This example is in The National Museum of the USAF at Dayton, Ohio.

Left: The Almen aero engine This shows the other side of the engine. The propellor mounting flanges are on the left, and the dual distributors to the right. Dual ignition was fitted, calling for 36 spark plugs. Photograph by kind permission of Phil Callihan. See his remarkable website at http://airpower.callihan.cc/default.htm

Left: The internals of the Almen engine Below the crankshaft is a sectioned cylinder containing one of the double-ended pistons. The cooling water pump is at bottom right.

Bore 4.25 in Stroke 5.5 in Displacement 1404 in3 (23,007 cc) Output 425 HP at 2000rpm Weight 749 lb Diameter 20in

The vital statistics of the Almen engine

 

[Chapap]

THE ALMEN A-4 WOBBLE-PLATE ENGINE: 1921

Left: The Almen aero engine: 1921 Eighteen horizontally-opposed cylinders in two sets of nine with a central wobble-plate; static barrel type. Water cooled. Rotary valve disc at each end of the engine. The A-4 was the fourth experimental barrel engine built by John O Almen of Seattle, Washington State, for testing at McCook Field, Ohio. The engine project began in 1921 and by the mid-1920s, the A-4 had passed its acceptance tests. Despite this success the Almen engine never went into production, because of a growing emphasis by the US Army Air Corps on air-cooled radial engines with large frontal area. European air forces generally preferred water cooled engines. Like other barrel engines, the Almen had a much smaller frontal area than other water-cooled engines of similar horsepower, promising reduced air resistance when installed in an aeroplane. It was rated at 425 hp but weighed only 749 pounds (a power/weight ratio of 1.76 lb/hp), a significant achievement for the time. This example is in The National Museum of the USAF at Dayton, Ohio.

Left: The Almen aero engine This shows the other side of the engine. The propellor mounting flanges are on the left, and the dual distributors to the right. Dual ignition was fitted, calling for 36 spark plugs. Photograph by kind permission of Phil Callihan. See his remarkable website at http://airpower.callihan.cc/default.htm

Left: The internals of the Almen engine Below the crankshaft is a sectioned cylinder containing one of the double-ended pistons. The cooling water pump is at bottom right.

Bore 4.25 in Stroke 5.5 in Displacement 1404 in3 (23,007 cc) Output 425 HP at 2000rpm Weight 749 lb Diameter 20in

The vital statistics of the Almen engine

That's a really cool mechanism. The sliding components at the head disqualify that engine for me though.

i wonder what happened with this. i couldn't really find any recent stuff on it. there was a few 2010 articles in engineering pages about how it works and then some lists of others who have also done single and two cylinder 6 stroke engines, but nothing really went to production.


kind of like the barrel engine design. maybe it was to good and the oil companies bought it out to keep oil "needed" as much as it is now?

It's tough to buy the coverup thing with the oil companies, but it sure is odd that these projects just seem to halt.

 

[Blmpkn]

That's a really cool mechanism. The sliding components at the head disqualify that engine for me though.


It's tough to buy the coverup thing with the oil companies, but it sure is odd that these projects just seem to halt.

It's easiest to buy cover-up stories concerning the health of one of the wealthiest markets in the world..

 

[don4331]

I recently saw a video of this. I imagine that this is a 100 year old idea, but there's a fella somewhere who made one that runs. This is probably the coolest odd engine I've seen. It adds another power stroke after the exhaust stroke of a standard 4 stroke engine. it goes:
intake > compression > ignition > (partial?) exhaust > water injection, steam expansion > exhaust

Of course I can't find the video I watched, but that seems super cool. He said he has it running but that's about it. It takes about 50/50 fuel to water and the block stays cool enough to touch. If the goal is to turn heat into power, this seems like a genius idea. All it is is an extra valve and a slower cam. Besides the typical making it work, this also has water in the cylinder which is typically undesirable. The six cycle wikipedia article is not much help... I'd need to read a dozen more wiki articles to understand that article.

Missed this 1st time around:

I played with this back in the '80s when I 1st read about Crower postulating it.

intake > compression > [hydrocarbon ignition] hydrocarbon expansion aka power > hydrocarbon exhaust > [water injection] steam expansion > steam exhaust​

You don't "need" an exta valve per say, but it "helps" to have separate valves for hydrocarbon and steam exhaust with other portions of the process i.e. the catalytic convertor would function very well with steam flowing through it.

Electronic direct injection makes this a whole lot easier to "tune" than historic manual injection (we used diesel injectors - which didn't take kindly to running with water).

The drawbacks of the engine:

Water doesn't do well when temperatures go below freezing - you don't want to mix ethylene glycol (antifreeze) with water - burning anti freeze is very bad for engine and/or environment. Air Forces mixed methanol with water to keep it from freezing, but they were injectioning the "water" along with fuel, not part of separate cycle, so the alcohol burned along with the fuel.* Environmentalists would have field day with clouds of unburned methanol coming out of tailpipe. I'm not sure if catalyic converter could process that volume of unburned fuel (you for sure would want a turbine downstream to take advantage of the combustion). If you can solve this issue, it is a viable technology.​

You have both the hydrocarbon and exhaust cycles doing nothing but wearing out the engine = less power for given displacement = bigger engine required.​

The steam expansion cycle isn't that powerful - there isn't extreme heat (other than hydrocarbon exhaust valve) to boil the water injected. One "power" stroke out of 2 is wimpy = less power for given displacement = bigger engine required.​

With current emissions laws, you need dedicate exhaust valve for steam exhaust (3 or 4 valves per cylinder works fine; 1 or 2 for intake (bass ackwards to normal practise - the intakes are smaller than exhaust, as 1 exhaust valve is for hydrocarbons, 2nd is for steam)​

You will need extra exhaust piping from engine to muffler (steam expansion is still going to be noisy and your neighbours will appreciate you attenuating the sound).​

Your engine's head needs separate ports for each exhaust valve.​

The advantages of the engine

No cooling system - you can adjust the amount of water injection to keep temperatures under control - for cold start up, you don't start injecting water until the engine is up to temperature.​

Better thermal efficiency - from 40% to >55%​

​

I think it would be cheaper/easier to do an MGU-H/MGU-K solution as used in Formula 1 engines to produce a hybrid drive train - less additional development (F1 engines are in the 55% efficiency range when MGU-H/MGU-K are considered)

* I say fuel as water injection works both in piston and jet engines.