Unique Cars, One-Offs, and Ill-fated Designs

[Blog Zbod]

Sorry to do this but a quick facts check is necessary.

Firstly it is not possible to build a 180° V configuration. Usual parlance in Blighty is either "Boxer" - as Olivier notes - or "Flat" as in "Horizontally opposed Flat 4" or "Horizontally opposed Flat 12" etc....

Sorry, my mistake. I was infected by the disinformazione from Ferrari's web site:

Apparently, so was Porsche, who seem to labour under the delusion they once built "a 180-degree V engine."


A boxer refers to a specific drive train architecture, one which has a separate crank pin for each piston, as in this 6-cylinder Porsche 911 crankshaft:

Six cylinders, six crank pins, the pairs of pins for opposing cylinders splayed at 180° intervals, which is the nuts and bolts of what facilitates its characteristic "boxing" countermovement:

Which is not the case with the 512 BB crankshaft, which has only half as many crank pins as cylinders...



...as does the crankshaft in the 12-cylinder Porsche 917, ...



...which means opposing cylinders must share a common crank pin, which precludes any "boxing." Unless something very expensive goes pear shaped.


Calling it simply a "flat" engine is a over broad and imprecise. An L-6 is also flat, it just happens to be stood on its side. I'm accustomed to hearing "boxer" and "horizontally-oppposed" used interchangeably, but even that is muddy because the cylinder bores in a 180° V tend to be more nearly perfectly aligned (i,e., "opposed") than those in a boxer. Which is why I choose to call a "flat" engine a "boxer" if it has boxer architecture, and a "180° V" if it doesn't. It leaves no ambiguity.

But the engine in the 512 BB, by Ferrari's own documentation, is not a boxer. I actually have expended some energy in the searching but have never uncovered a single instance of Ferrari ever building a boxer engine, not even un prototipo. Which is why I bothered to broach the topic in the first place.

 

[FB]

Nothing to do with F1 but this video is astonishing. Someone has take the time to connect together 16 3 cylinder Kawasaki 2 stroke engines to make this monster.

The engine might run but I bet no one had the guts to ride it.

 

[Fenderman]

Italians are out to confuse us ...

.... for here in the page describing the engine, lo and behold they describe it as a boxer!

http://www.ferrari.com/Italian/GT_Sport_Cars/Classiche/Tutti_i_modelli/Pages/512_BB.aspx

"Presentata al Salone di Parigi del 1976, offre il 12 cilindri boxer con una cilindrata che sfiora i 5 litri. Si afferma la sistemazione posteriore/centrale del motore che, rispetto a quello installato sulla 365 GT4 BB, fornisce la medesima potenza ad un regime di giri inferiore ed offre maggior coppia e fluidità di funzionamento. La carrozzeria di Pininfarina presenta solo piccole modifiche rispetto al modello precedente: dettagli che la rendono ancor più elegante e migliorano anche il raffreddamento del propulsore."

"Presented at the Paris Salon of 1976, offers 12-cylinder boxer engine with a displacement of nearly 5 liters. It says the arrangement rear / mid-engine that, compared to the one installed on the 365 GT4 BB, provides the same power at a lower RPM range and offers more torque and smooth operation. The bodywork by Pininfarina shows only small changes compared to the previous model details that make it even more elegant and also improve the cooling of the engine."

Actually I must apologise for being a little unkind there. The confusion is obviously with regard to descriptions of engine types and crankshaft configurations.

"V" engines come in two main varieties. One is the "cross-plane" engine and the other the "flat-plane" engine. Term "plane" in this context refers to the crankshaft configuration not the engine configuration. Using V8's as an example for simplicity, the crank shaft in a "cross-plane" engine can have four shared (or eight individual) crank pins set at 90 degrees to one another. Looking at the crankshaft end on, it will resemble a "X" shape. A "flat-plane" V8 may have only two shared (or four individual) crank pins in the crankshaft at 180 degrees to each other.

Similarly a boxer engine may have a crankshaft configuration whereby it is either "flat-plane" or "cross-plane". Generally speaking the cross-plane configuration engine produces less vibration since the off-set of the crank pins and therefore the forces acting on the crankshaft transmitted through the conrods cancel each other out. Flat-plane engines tend to produce more vibration but also produce more power (I forget exactly why that is). Suffice it to say that engineers have sought to experiment with different angles of off-set, particularly in engines with 10, 12 or more cylinders in an effort to reach a better compromise of power versus vibration.

Regardless of the the crank shaft configuration the terms Boxer, Flat (as in flat 6 etc), "V", "H" etc refers to the cylinder orientations of the different types of engine.

If folk's don't believe me you can find further reading here:
http://en.wikipedia.org/wiki/Engine_configuration
http://www.howstuffworks.com/question366.htm

... and any number of other internet sources.

 

[LifeW12]

Has this been posted? I think not.