Why not use a boxer engine in a boat?

[halfmoa]

Re: Why not use a boxer engine in a boat?

Can someone please enlighten me in the differences between a "boxer" engine and the 180 degree 4cyls (i.e. air cooled VWs) please? Subaru seems to be hailed for using a design that's not even remotely new.

 

[QC]

Re: Why not use a boxer engine in a boat?

Can someone please enlighten me in the differences between a "boxer" engine and the 180 degree 4cyls (i.e. air cooled VWs) please? Subaru seems to be hailed for using a design that's not even remotely new.

No difference. Opposed pistons on a common crank are "Boxers". Porsche flat 6 cyls, Original VWs, BMW Motorcycle, some aircraft are all Boxers. For some reason, when I was Googling about the Ferrari engine, some are saying it is not a "true" Boxer because it was originally a V design and now laid flat . . . Why doesn't that qualify?

The common crank comment is due to a design that has opposed pistons actually going towards each other without a cylinder head, but two cranks. Very odd design and still being worked on. I visited this place recently: Achates

They do something like this, and it is not a "Boxer" as commonly used:

 

[Lyle29464]

Re: Why not use a boxer engine in a boat?

I knew you'd appear. Take any horsepower rating and design the hull around the drive, and a trimmable drive will be faster. Especially if applied aft. I have never said, that an inboard cannot be fast. But a trimmable drive is faster . . . It's true, and I will debate it as long as anyone wants.

I have 4 inboards ( he is correct) The angle of the shaft kills you and the weight forward drives the nail in the coffin. Now a surface drive is a different story.

 

[halfmoa]

Re: Why not use a boxer engine in a boat?

For some reason, when I was Googling about the Ferrari engine, some are saying it is not a "true" Boxer because it was originally a V design and now laid flat . . . Why doesn't that qualify?

I don't know because the nature of a boxer engine appears to come from the flat plane crank design...just Ferrari had in the Vs...

 

[QC]

Re: Why not use a boxer engine in a boat?

I have never been critical of an IB's simplicity, or even their validity as a marine propulsion option. I own one too, but my point is simply an engineering/physics discussion. Efficiency and speed are best served with a trimmable drive, even with horsepower losses through two 90 degree turns (one with an OB). The surfacing drive has always been a favorite of mine as some designs limit gear train losses by being "straight through". There are definitely practical and safety issues with those though too.

There are some reasons that IOs are so popular despite being an engineering abortion

 

[mrdancer]

Re: Why not use a boxer engine in a boat?

No difference. Opposed pistons on a common crank are "Boxers". Porsche flat 6 cyls, Original VWs, BMW Motorcycle, some aircraft are all Boxers. For some reason, when I was Googling about the Ferrari engine, some are saying it is not a "true" Boxer because it was originally a V design and now laid flat . . . Why doesn't that qualify?
[/IMG]

You forgot the best boxer engine series of all - those found on Honda's venerable GoldWings. Where else can you find such power and refinement in an engine no louder than a sewing machine?

Now, what do you call an engine that qualifies as half of a boxer (e.g. - the "Johnny Popper" two-cylinder engines made by John Deere in the 1930s - 1950s)? Very torquey and very economical for their size.