FerrariAds.com V-12 section slightly incorrect

Dead horse time again.

Ferrari's "flat 12" cars are not real boxer motors, but rather 180 degree V12's. The heading is correct.

 

The Ferrari Boxer and TR engines are 180 degree V12s...

 

and

Huh?

New info to me. So you're saying the V12 engines are a 90-degree crank (V-configuration) but in boxer (180-degree) orientation? Wait, I just confused myself... This has something to do with cylinder orientation and crank angle (what is the term again?), right?

 

I believe most of the older "pure" V-12's are 60 degrees, not 90. The more modern ones (456, 550, etc.) are 65 degrees.

 

The term "boxer" in english differs from the german "boxermotor".

It relates to the phase relationship between opposed cylinders.

http://en.wikipedia.org/wiki/Horizontally-opposed_engine

 

Thanks for the link DGS.. interesting!

 

Thanks for the link So, the 180° V12 engine has a V-shaped cylinder arrangement but uses a flatplane crank, correct? The Wiki wasn't very clear on English vs. German definitions, at least for me.

The flat-12 engines, like the BB, are boxer motors (horizontially-opposed piston layout) with 180° cranks (flatplane), correct?

Bear with me, I'm trying to understand this better.

 

I'm confused!!

 

Interesting, I always thought that the BBI (Boxer) got it's name from the engine configuration, I take it this isn't true?

 

The Ferrari road flat 12's are horizontally opposed, flat, 180deg engines, with the crank timing of the V-12. They are not true boxer motors.

 

Don't confuse flat crank with horizontally opposed. They're completely different issues.

In a flat crank, the crank pins are on opposite sides of the crank centerline - 180 degrees apart. All the pisons on one bank reach TDC or BDC at the same time. In a cross arrangement, the crank pins are 90 degrees apart.

In the Ferrari world, we take flat cranks for granted, but most "muscle cars" use a cross crank ... and they envy the sound of our flat cranks.
(The firing order on a flat crank alternates between banks -- on a cross crank, it usually doesn't, so you get sequential exhaust pulses into the same exhaust side periodically, giving the "muscle car" rumble in a dual exhaust.

On Ferrari engines, pistons on both arms of the "V" share the same crank pin. One bank hits TDC 90 deg after the other bank, in a 90deg V.

In a 180 deg V with a flat crank, opposed cylinders hit TDC 180 degrees apart. So when one piston is at TDC, the opposed cylinder is at BDC. They both move to the right or left (relative to the engine centerline) at the same time.

In a boxer engine, the opposed cylinders do not share the same crank offset, and they hit TDC at the same time. They're both moving in or out at the same time.

Picture a boxer punching his gloves together before a bout.
Then picture Futurama's Bender doing the "Go Bender" dance, with the arms going back and forth at the same time.
That's the difference between a "boxer" and a 180deg V.

The following animations are from http://auto.howstuffworks.com/engine1.htm (and one from atlasf1): (I couldn't find an animation of a 180deg V on the web)

The first shows a boxer flat-4. The opposed cylinders are on different crank pins and TDC at the same time.

The second shows an inline 4 with a flat crank. Cyls 1&4 and 2&3 TDC at the same time. A Ferrari V8 is like two inline 4s sharing the same flat crank.

The third shows a cross-crank V6, where each piston has its own crank pin. Compare that to the simple diagram of V cylinders on a common crank pin.
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Interesting stuff...

 

Nice post. Very informative, thanks!

BT

 

Very cool CAD animations, as well.

 

To bring this around full circle, the TR does NOT have a V12 engine.

The cylinders are not arranged in a V. I'm sorry but a V has an acute angle between the banks not 180 degrees.

 

In the strictest technical sense the opposing cylinders do not form a V, in the world of internal combustion nomenclature it is a V engine therefore it is a V12. Just as the Ferrari 360 coupe is not actually a city in Italy, we still call it a Modena.

 

LOL

 

This is nothin Doc. You should come over and ck out the latest in timing belt threads.

 

I saw. I'm doing my best to stay out of that one.

Merry Christmas Brian.

 

Do they use a "V belt" in the Boxer?

 

Aw come on, it's gettin fun.

Merry Christmas to you too.

 

SSSSShhhh!

I told you not to tell anyone.

 

I will in a little while. It's only 4:20 here, I need to wait until 5 PM so I can wade into the pool with a beer in my hand...

 

A 180 degree "V" belt, LOL

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