I know the 928 engine fires every 90 degrees of crank rotation, so it would be 90,90,90 270 right? I was also told that the Ferrari engines are even fire motors? I'm very ignorant on the matter so someone please shed some light.

 

Every piston fires every 720 degrees of engine rotation (once every two revs), so on a V8, you get 4 cylinders firing per revolution, which averages out to one combustion every 90 degrees of rotation.

If the crankshaft journals are offset - those for opposing cylinders are split a bit so that firing cycles are evenly spaced -- the split adjusts for the fact that the V shape is 90 degrees off (or in some V8's 60 degrees off -- then you get cylinder firings at evenly spaced 90-degrees of rotation times per revolution. Almost all American, German, English, and Japanese V8s use this type of crankshaft. It results in "even" firing.

Ferrari uses a "flat" crankshaft - the journals for opposing cyliners are not offset and in fact the journals are al 180s out of phase. As a result in a V configuration the cylinders fire four times per resolution but with a timing somewhat uneven. These crankshafts are used for a variety of reasons/excuses. They make more vibration but are stronger (some say) and lighter (probably true). I have not heard the term "odd" used for this firing cycle (this is not an even-odd thing, but an even-uneven thing).

If the difference seems confusing, think of the sound a Harley engine makes -- it is a V twin with no offset in the crank journals (like Ferrari) only just two cylinders, so the cylinders fire unevenly in time -- pow-short delay-pow-long delay- pow-short delay-pow-long delay . . .and so forth. Some big Japenese V twins don't make that uneven rythum because they use an offest crank journal for their two pistons. A Ferrari V8 is sort of like four of those Harley's bonded together, each pair having that uneven staccato sound. It doesn't sound like a Harley because of some other differences and because there are four sets of pistons feeding into two headers and it revs alot higher, etc.

 

danka schoen. I'm studying an A.S.E. book but it doesn't have anything about this in it.

 

Well, there is a lot you won't get by reading any one book. This is covered in several engineering books I have, and you certainly see it when you take apart, say, an GM LS6 V8 vs. a Ferrari 430 V8. (the Ferrari, by the way, isn't the better engine, just the more expensive. I actually like the Chevy more - a bit lighter, fewer parts, and with more stock HP and torque)