Calling all mechanical engineers

[Retired Army]

Not being blessed to have a degree in engineering, I am wondering if the movement of the pistons in the F6B in relation to the frame mounting contribute to the incredible smoothness? This combination has been around since the inception of the gold wing.

[bob109]

Not being blessed to have a degree in engineering, I am wondering if the movement of the pistons in the F6B in relation to the frame mounting contribute to the incredible smoothness? This combination has been around since the inception of the gold wing.

The flat horizontally opposed 6 has self canceling vibration characteristics because there is a piston at Top Dead Center (TDC) on each side of the block at the same time. One piston is on the compression stroke and the other piston is on the exhaust stroke. This design provides the notorious smoothness of the F6B motor. Some automobiles like the Subaru's display the same smoothness as they have a flat motor design and opposite pistons at TDC simultaneously.

[unsub]

Not being blessed to have a degree in engineering, I am wondering if the movement of the pistons in the F6B in relation to the frame mounting contribute to the incredible smoothness? This combination has been around since the inception of the gold wing.

From Wikipedia:shrug:

The movement of the pistons in a horizontal engine is all in the same plane, so it creates less vibration than in a V-configuration engine; particularly one, like a V6, with an odd number of cylinders on each side of the engine. Unlike the V6 but like the inline-6, the flat-6 is a fully balanced configuration which is in perfect primary and secondary balance. The three cylinders on each side of the crankcase tend to have an end-to-end rocking motion, like a pair of inline-triple engines, but in the usual boxer engine configuration, the imbalances on each side cancel each other, resulting in a perfectly smooth engine.

The flat-6 is also smoother than the flat-4 or inline-4 because the power strokes of the cylinders overlap in a four-stroke cycle engine. In these four-cylinder configurations, pistons are 180 degrees apart in crankshaft rotation and start their power strokes every 180 degrees, so each piston must come to a complete stop before the next one commences its power stroke. In the flat-6, each power stroke begins 120 degrees after the previous one starts, resulting in 60 degrees of overlap between power strokes and a much smoother delivery of power to the flywheel.

[Scotrod]

The engines relationship to the frame has virtually ~nothing~ to do with smoothness. The opposed cylinder design is what does it.

There is also an opposed cylinder opposed piston design out there than looks interesting;

http://www.ecomotors.com/

Turbo 2 stroke. Power to weight/power to size ratio (power density) and efficiency are both very impressive.

The technology of Opposed pistons isn't 'new',,, the diesel engines in some of Germanys WW2-era balloons had a similar design in the Junkers Jumo 205 aircraft engine:

http://upload.wikimedia.org/wikipedia/commons/0/05/Jumo205_cutview_02.jpg

The OPOC looks like it's getting support from / going to be built in China:

http://www.motorauthority.com/news/1083498_ecomotors-opposed-piston-engine-to-be-built-in-china

http://www.greencarreports.com/news/1083457_china-to-build-ecomotors-efficient-opposed-piston-engines

The piston-equipped engine, as we know it, is long overdue for a refresh,,,

[4DI2D]

BMW's boxer seems to have started something.
Volkswagen's opposed four and the original Wing design differed mostly in cooling.
In the Forties the first helicopter engines were air-cooled opposed sixes specifically to reduce vibration in the airframe.

Honda didn't do anything new . . . they just did it BETTER!

[Retired Army]

Thank all of you for the great information.

[smokinjoe187]

Thank all of you for the great information.

now lets work on world peace!

[Scotrod]

It takes a little while for the gif file to load, but here's how the OPOC engine works:

http://www.ecomotors.com/sites/default/files/crank-block-loop.gif

Great balance, piston speed cut in half compared to a 'conventional' piston engine of equal size (less wear, less drag, capable of higher rpms)

[Scotrod]

The OPOC Advantage
The OPOC engine could represent the next generation in diesel technology, and its advancement may prove as potent to diesel performance as turbocharging, intercooling, and direct injection werecombined. EcoMotors promises its engine:
1. Uses 50 percent less parts and is projected to be much cheaper to make than today’s engines
2. Has no cylinder head or valvetrain to cause problems
3. Is capable of 15 to 50 percent better fuel economy
4. Does not create excess waste heat, so the need for a large cooling system is reduced
5. Creates fewer exhaust emissions, which negates the need for expensive exhaust aftertreatments


Navistar Ecomotors Diesel Engine Side Shot

Inside Navistar’s Diesel Of The Future
Manufacturer: EcoMotors
Location: Allen Park, Michigan
Engine: EM100
Type: Two-stroke, opposed-piston opposed-cylinder (OPOC) turbodiesel
Cylinder bore: 3.937 inches (100 mm)
Dry weight: 296 pounds
Dimensions: 22.8L x 41.3W x 18.5H in.
Horsepower: 325 hp at 3,500 rpm
Torque: 664 lb-ft at 2,100 rpm
Power density: 1.1 hp per pound


Read more: http://www.dieselpowermag.com/tech/1106dp_navistar_ecomotors_diesel_engine/#ixzz31wIa4fHJ

664 ft lbs from a 2 cylinder w/4 inch bore's??!!??? YEAH BABY!!!!! :banana:

[MarcPW]

Do you know that originally the plan for the first GW (GW1000cc) was based on a flat six as we have today, but the ingeneers deemed it as too soon for this kind of technology, that it will scare motorcyclists away from Honda, so decided on a 4 cylinders... Honda created this 1000 cc just to beat Kawazaki who just made a 900cc motorcycle. (I forgot the model)

[Phantom]

Do you know that originally the plan for the first GW (GW1000cc) was based on a flat six as we have today, but the ingeneers deemed it as too soon for this kind of technology, that it will scare motorcyclists away from Honda, so decided on a 4 cylinders... Honda created this 1000 cc just to beat Kawazaki who just made a 900cc motorcycle. (I forgot the model)


Also ….. PORSCHE has been making 911's with the flat six engine since 1964, long before Honda. Today the Porsche 911's still use the proven flat 6 boxer engine, Subaru is another. Our Beloved F6 is basically a automotive engine placed in a motorcycle frame.

[Bruce B]

Many, if not most, light aircraft have been powered by horizontally opposed engines built by companies such as Continental and Lycoming since way before I can recall and I'm 71. Even today they dominate the market until you get into the very upper end of it where you find turbo props and jets. The flat engine was around a long time before Honda started tinkering with it but when they did, they sure did a good job of it.

[bob109]

Also ….. PORSCHE has been making 911's with the flat six engine since 1964, long before Honda. Today the Porsche 911's still use the proven flat 6 boxer engine, Subaru is another. Our Beloved F6 is basically a automotive engine placed in a motorcycle frame.

Not to confuse but a Flat Six Boxer Engine has six individual rod journals on it crankshaft. Our Flat Six F6B Motors are considered 180 degree with the crankshaft employing only three rod journals. Two connecting rods share the same journal! When one piston is at TDC the shared journal piston is at BDC:icon_wink:

[BIGLRY]

Not to confuse but a Flat Six Boxer Engine has six individual rod journals on it crankshaft. Our Flat Six F6B Motors are considered 180 degree with the crankshaft employing only three rod journals. Two connecting rods share the same journal! When one piston is at TDC the shared journal piston is at BDC:icon_wink:Yep, here is the flat 6 Boxer engine with 6 rod journals, But I must disagree with your view that the Honda Goldwing flat six only has three rod journals as you can clearly see in the pic below the one of the Boxer engine. Also that is why one side of the F6B engine is offset front to back due to the pistons not being evenly across with each other.:icon_wink:
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http://www.maxsalvage.com/servlet/the-4664/04-Goldwing-GL-1800/Detail

[bob109]

Yep, here is the flat 6 Boxer engine with 6 rod journals, But I must disagree with your view that the Honda Goldwing flat six only has three rod journals as you can clearly see in the pic below the one of the Boxer engine. Also that is why one side of the F6B engine is offset front to back due to the pistons not being evenly across with each other.:icon_wink:
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http://www.maxsalvage.com/servlet/the-4664/04-Goldwing-GL-1800/Detail

I stand corrected! Not sure why I was under the impression the 6 had only three rod journals! Live and learn:icon_biggrin: Thanks for the correct info and pic's of the cranks:icon_wink: