in-line 6 Cylinder Engines, 'straight-six'

Less cylinders means each cylinder is bigger, more. Mass per piston for same displacement.
That is why higher rpm engined have more cylinders to Rev easier. Truck and boat engines want torque, therefore long strokes. Big pistons. Rpm and rotating mass not issue.

 

Fuel economy is much more complicated than torque management and gears. It is the heart of the combustion chamber and its breathing, its fuel injection.

Plus there is the want and the need for economy which I have to say the American consumer has never been strong on believing that If they can afford it then they will have a big car feeling no personal responsibility for fossil fuel depletion.

In Europe it is far more socially irresponsible to have a large fuel guzzler driving for better mileage by the manufacturers.

Parking a Hummer in Uk is met with frowns of disgust, certainly not admiration.

 

brian, i am a bit biased when it comes to choosing a diesel engine for a large displacement hull. if buying new john deere are nice engines and smooth. 2nd hand i would still buy a gardner. you get a lot of engine for your money with j.d. i worked on john deere graders years ago and was impressed with how smooth and clean they were.

 

A Bentley, Rolls, Ferrari, Lamborghini, all have similar fuel consumption as a Hummer, they just cost at least four times more. My F250 can out pull a Hummer and gets better mileage than most sedans, double a Bentley or Hummer.

 

The Bentley and Rolls yes, the sports cars no.
I've owned a Maserati Ghibli for many years and still have a Porsche 928. Both can do approx 22 mpg if you put your mind to it, a Hummer uses more even when towed. Vehicle weight and shape determines fuel consumption.

The most thirsty car I ever had was a Blazer K5. I had to trade it in for a Mazda RX-7 because I constantly had a cold from visiting windy gas stations in the middle of the night. American cars back then seemed to use gas for cooling, there's no other way to explain the ridiculous fuel consumption.

 

a new 640hp vette can do US 25mpg
any other sports car close to that ever?

 

Corvettes run down the highway at about 60 kmh/35 mph per 1000 rpm IIRC.
The 640hp ZR1 is about 20mpg US on the highway with the regular Vette/stick being 25 mpg.

Several Porsches including the 550 hp Panamera Turbo S and the 911 Turbo S get 24-25 on the highway.

And surprisingly many larger SUVs can get 25 mpg if carefully driven on the highway..so long as you take it easy..it seems once you go 65mph ( or 105 kmh) or faster they really start sucking the gas.

 

Fuel Economy of American Cars

There are a lot of correct American bashing above, as related to auto fuel economy. Our fuel prices in this country have never been a big burden or concern until crude began to reach $100 and our retail prices began to climb. Then all of a sudden in typical 'knee jerk reaction' the public ask 'why do our vehicles get such poor mileage in relation to the rest of the world. The auto executives just past the blame off as 'this is what the public wanted...bigger cars...ever bigger engines'. Besides who cares about some extra fuel usage when the majority of the States exact a large part of their operating budgets from the taxes on this fuel usage.

In other words not only do we have to battle the technology questions of getting better fuel mileage, we have to combat this political infrastructure that 'lives' by these higher fuel consumptions.

You can bet the American trucking industry has been out their seeking better mileage and durability....their livelihood is at stake. But even these guys have had to deal with the basic manufactures of engines, and often that brings you back to the big three auto makers, or the smaller scale 'independents.' It is these smaller scale independents that are the real innovators, but they can place themselves at financial risk by getting to innovative too quickly, and a few have produced ' less than optimum engines.

Part of the reason for this subject thread, is to sort thru a few of these 'less than optimum' engines for inclusion in a new motorsailing design....and hopefully some of this 'sorting' will come by way of folks who have had real life practical experiences with some of these MARINE engines.

 

i think the boating industry is way behind

I was asked a while back to compair the car industru to the boating industry , After i had written a couple of pages i realised the boating industry is so far behind it not funny , its just about inpossible to compair the two side by side !!.
Think about the Family car ,!its lighter, faster, its aerodynamicly designed, safer , more powerful from a much smaller quite efficent motor and more compact than all those older square shaped heavy gas guzzlers monsters we saw as kids .
ok now swing to the boating industry , wheres the change ?? where are they ?? shape sort of but is it better aerodynamicly designed ?? is it lighter weight ? sure its got a core here and there ,over all nothing much has changed at all .the outboards keep getting bigger as time goes by fuel tank get bigger to feed all those hungry hosres for longer . So who do we point the finger at ? boat designers or at ourselves for not forcing change to take place for the better ?
Come to think of it do we realy need a boat at all what useful purpose does it serve ?? if you didnt have one what would your life reall change that much ??
Would it be better to just rent a boat when ever you wanted and take it back when you finished . makes more sense!! get a sheet of paper and write down everything you spend on !!boating , what are the good points and what are the not so good . the miles per gallon is terrible , its more like gallons per mile . And the bigger they get ooooh ,i cant bare to think about it .

 

I see what you mean Tunnels...all the marine industry can really do-and has done- is go to piezo injectors and high pressure common rail injection.
For boats that have varying speeds-add CPP. Other than that I don't see what more they can do.

Aerodynamics...not useful for slower boats,and most fast boats will be going slow most of the time anyways to conserve fuel.
My boat is quite aero-designed,but I rarely use that function.Myself,I can't imagine not having a boat-but I live very close to spectacular fishing and cruising grounds.

Plus consider the average use for most boats is maybe 100 hours a year.

 

areodynamics is for all things including huge building and buses and trucks ! specially long haul . they are quieter they dont move so much in the wind and the faster you go the more the shape holds you on the road by pushing the whole care down onto the road to get better grip .
Boats theres day seem to just make bigger bow waves and push more water .
We have the materials to make better safer and much lighter boats . with design there could be a revolution of change take place but we have our heads stuck in dark places and just accept things as they are !!
Motors have come a long way and electronics and technology has done wonders for the humble piston engine ! and they still trying to get more from less . seem boat are just content to get less from more and the more ugly they are the more we ooh and aaah because we dont want to appear idiots and say its horrible looking !!. How dare you !!

 

I am happy to say the "bubble boats" of today are darned fugly........never seen one yet that could be described as pretty.

 

I'm big fan of old American I-6 motors. Don't forget Fords.

I used to have 1962 Falcon van with 170cid 6, with solid lifters. You had to adjust them with the motor running. You did that sitting in driver's seat with doghouse lid up. Full size van that got near 20mpg if driven easy. What has improved in 50 years?

Other great Ford 6 engine (hydo lifter 200cid) came with Mavericks. Very simple to work on and dead reliable. Buddy went to junk yard and ripped out electronic ignition and it all dropped in and fired up on first try.

Arguably the best motor Ford ever made was 300cid used in full size trucks and a few vans. Both carb and FI versions. Got my eyes out for one now. Much longer life than 6v and easier to work on, with better MPG.

Drove Dodge 3sp full size van with 318cid 6 as delivery van up in some hills, what a tower of torque, and so much easier to work on that V-8, in van especially.

The classic 225 slant six was in a buddies full size Dodge pick-up. Good mpg and dead reliable, and when finally blew at 300,000+ miles he got one out of junk yard for $150 and it dropped right in. Much easier with just one intake and exhaust.

I've always felt the longer 6 gives the car a certain ride and stability others just don't have.

The new (1990->?) Dodge pickups have Cummings 6 diesel, another truck I'm looking for. Not sure if anyone has use the motor for boat.

 

I never hear much about the Atlas inline 6 chevs they look good to me.
anyone?

 

"In Europe it is far more socially irresponsible to have a large fuel guzzler driving for better mileage by the manufacturers."


That is insane!!

As much of Euro- land is socialized !!

Since the accident damage to driver and passenger goes DOWN with every 300 lbs increase in vehicle weight a stronger heavier vehicle is the most socially responsible choice.

What would be a fender bender in a M-B , might be a week or month of intensive care from a Flea , "Smart Car".

At $10,000 plus a day for intensive care the difference in "social" costs would favor the 10mpg fuel hog , rather than the flea sized death trap .

FF