mad_machine wrote:
yes, ferrari's flat plane crank puts the firing pulses "in order" from 1 to 4, 1 to 8, or 1 to 12 depending on the engine. I have heard that the exhaust note of the flat plane fours is rather unpleasant (flatuating cow in a bucket was the description) but the rest are pure music.
No.
No matter how the crank was shaped, that firing order would vibrate like crazy. (Depending on how you count 1-8 or 1-12, it would either fire from front to back, sequentially, and make the engine rock front-to-back, or it would go 'round the engine bay in a circle, and shake the motor in a circle.) The point of the flat-plane crank on a V8 is that it makes the power pulses perfectly even. There is one cylinder firing every 90 degrees of crank rotation, and it alternates between banks every time. Each bank functions like a 4-cylinder, with power pulses coming from the other bank of the motor smoothing out the spaces between its own.
Here is the firing order plaque for a 308.
The firing order runs vertically, at the lower left corner of the tag.
Each bank fires in a 1-3-4-2 order, alternating banks.
A ferrari V-12 doesn't have a flat-plane crank, and it, too, acts like two inline motors.
Here's the firing order for a v-12:
Each bank fires 1-5-3-6-2-4. The crank's journals are separated by 120 degrees
Each bank has a balanced firing order, each of the 4 exhausts has a balanced firing order. It's mechanically pretty cool, but even better, it's smooth. I like motors in general, but V-12s I love.
The ferrari 4s sound pretty rough at idle -- but they're full-on race motors, with huge carbs and huge cams. At full throttle, they sound awesome.
