Car engine vs. outboard

Frosty I drove the 928 every day for almost 7 years and paid the fuel bills. Once the mass is in motion there is very little power required to maintain speed; even at 150 km/h (3000 rpm) on the German Autobahn consumption was approx. 10 ltr/100 km. In city traffic it tripled.

I think this says something about aerodynamics, not about special engine constructions. Do not forget the car is only 1.25 m (4 ft) high.
The Bosch mechanical injection system was governed by the driver's foot, speed and vacuum: once at speed the giant intake diaphragm almost closes because a handful of horsepowers is enough to maintain speed. And there was of course no exhaust cat to feed.

Also I may have exaggerated a tiny little bit when comparing it to the Ka. I may be able to drive it more economically than my wife does, she often floors the pedal because the little engine doesn't match her temperament.

 

Are you sure its not a 9 cylinder radial?
Where is the 9th injector?
Start enrichent?
Just curious

 

100% correct powerabout. Number 9 is in the intake plenum and pours in gasoline during starting and a short time afterwards.

 

True, the new 2 stroke seem to do well, particularly in the price tag. I wonder if it is worth paying that much more for a 4 stroke. I like the honda because I hate noise.

 

If you hate noise then don't buy the Honda 4 stroke. I dont know what size your getting but the 4 Hp is a damned annoying noise, and an extremely unreliable engine too.

Ive seen them thrown away in the garbage on the dock here, I picked one up once and thought Ide take it back to the boat and play with it, The carb was knackered and new one was the price of a motor. I asked the local dealer if he had a scrap carb, he came out with a whole engine and gave it to me.

The noise though I hate the noise.

Now the 200Hp that a different kettle of fish, very impressive.

 

He he, 4Hp that is not an outboard, it's a blender...
Only Kidding
I will have to replace my Evinrude 25 (1996) soon since I have to drive the tinnie with earmuffs on. It's a pitty because it goes like a rocket. More pitty if I look at the pricetag for a 25HP Honda. Worth more than the tinnie with Evinrude thrown in.
The 20hp is substantially cheaper. I probably don't need 25HP anyway.

Couldn't you make one out of the two honda 4?...may be you need a dozen?

 

No --4' into 25 = 6,--well 1 hp down.

That would look cool, post a photo when you get it hooked up.

Have you seen the pic of the big RIB with 8 x 200hp on the back.

No thats not a typo. If this wifi connection was working good enough I would post it but some one may do for you.

I think its 8 --maybe 10.

 

All this is not quite strictly correct. You need to have some more design parameters to gauge the efficiency of a boat vs. ground.

Strictly speaking, most automobiles have many times more engineering in their powerplants and are more efficient than either airplanes or boats.

Diesel-electric trains with regenerative breaking are probably the most efficient, as the types of loads a train experiences are well suited to electric hybrids.
Most large boats are designed with reducing fuel costs and maintenance rather than engine economy. IE, bunker oil is not a very highly engineered fuel. Most small boats, I don't think consider efficiency at all.

How Barging Compares with Rail and Truck

This chart summarizes how barging compares to the rail and truck modes of transportation in terms of fuel efficiency, the number of units of production required to move an equivalent amount of freight, and the resulting impact each mode has on the environment.

Clearly at velocities below the hullspeed of a vessel, water travel is MUCH more efficient than land travel. Its only when you want to go fast that you run into problems.

Fuel economy vs. mode of travel:

Barge Train Freight
FUEL EFFICIENCY(1) 514 miles 202 miles 59 miles
BARGE EQUIVALENTS(2) 1 barge 35 cars 120 trucks
TOW EQUIVALENTS(3) 1 Tow 140 cars 480 trucks
EMISSIONS RATIOS(4)
Hydrocarbons plus Nitrogen Oxides 1.0 14.2 17.5
Carbon Monoxide 1.0 1.9 74.4
Particulate Matter 1.0 12.0 12.0

(1) These are the miles one ton of cargo can be transported on one gallon of fuel.
(2) One barge can transport 3500 tons of cargo. That is equivalent to 120,000 bushels of wheat or 1 million gallons of fuel.
(3) One tow, consisting of a boat and four barges is 650 feet in length whereas 480 trucks spaced evenly with 150 feet between trucks is 20 miles in length.
(4) Eastman Data Emissions Comparison: This is the ratio of emissions for trucks and rail as compared to a four-barge tow on a ton-mile basis. So, for example, trucks emit 74.4 times the Carbon Monoxide of a four-barge tow on a ton-mile basis.

 

can you add a large freighter like a 747
200 tonnes moved 12,000 miles for about 100 tonnes of fuel?

Edit >100 tonnes of cargo with almost 200 tonnes of fuel for 10,000nm..leaves car for dead.....
380 has 300,000ltr capacity

I guess the Emma Maersk beats them all?

 

Non of these examples are comparable, chalk and cheese.

So what we gonna do go back to horse drawn canal barges.

Not really suitable for live organ transportation.

Economy is good but not always the priority.

I think the Airbus 380 has the edge,110,000 liters per hour if I remember correctly, ha ha it makes you laugh does'nt it.

edit--- na,-- that cant be right ille check it out.

edit --2 -- 3 liter per person per 100km

 

I think the main thrust of my post, is that water travel is not inherently less efficient than driving.

It can be more efficient. Just not when you exceed your hullspeed, unless you are hydroplaning/foiling (maybe).

But the other important point I was making is that the automotive industry has invested considerably more money into thier engine tech than the boat community, because boats are effectively unregulated in comparison to cars, that and the engine market is only barely competitive in comparison.

It is even true compared to the airline industry. For instance, Subaru, Toyota, Mazada, etc engines in the sporty models often have better power to weight ratios and efficiency than many piston aircraft engines. However they aren't rated as airplane engines, so can ussually only be used for experimental aircraft.

For boats though.... they could work out great.

 

There is more drag in water then rolling resistance hence the smallest engine to get from a to b in any medium will be on the road
BUT
Shifting freight by large ships makes hybrid cars look absolutely primative
Large ship engines and some gas tubines are at 50% efficiancy nothing else is close.

Big ship 14,000 teu so 7000 40 footers with 100,000hp completing with 7000 trucks of 500hp each =3,500,000hp
The ship burns a product that is mostly a waste product with 50% efficiancy and the truck burns a refined product that cost 3 times as much with less efficiancy
Now you see why European countrys are continuing to build canals......
The US continues to build roads....

 

Turbine and turbine electric with waste heat recovery is definitely THE way to go. You can get operating efficiencies even higher than 50% esp if you need to run things like refrigeration HVAC etc.

You can actually get near this with even small micro-turbine combustors with waste heat recovery. There aren't many commercial solutions though, and they are all expensive. Nothing to stop you from doing this at home though, its one of my "other" projects.

 

In fact the boat community hardly invested anything at all, at least not in technology. Primitive engines no car maker can afford to put in his cars anymore are still installed in boats every day.
The two major players on the I/O market have ensured their market share by buying boat manufacturers instead of competing with better technology.

One can argue that inefficiency is less important because recreational usage is only a fraction compared to road traffic, or that simple engines are more reliable so better suited for marine application.
But every gallon of fuel wasted cannot be used for other purposes and even these "simple" marine engines don't turn without electricity because they have a starter motor and fuel valve, so they might as well have an efficient injection system as well.

I think the main reason behind the current situation is profit.
The boating world is a dumping ground for old fashioned, cheap technology, sold at premium prices with a "marine" label on it.