ANFSCD - the spark
Making this separate since is completely different.
The nice thing about a straight 6 or a 60 degree bent six is that you fire one cyl every 120 crank degrees which makes a single intake plenum and exhaust very good for scavenging (if you really want to know see http://en.wikipedia.org/wiki/Helmholtz_resonance ). Can also be used to create a quiet exhaust without mufflers or restriction. Doesn't work if you have really wild cams but for the street is very nice.
Can treat a V-12 as two sixes for best tune.
A 90 degree V-8 fires every 90 degrees so is best to treat as two four cyl engines which prevents overlap. There have been a number of attempts to smooth out an 8 (or 10) but flat cranks really vibrate and the Ford "bundle of snakes" exhaust only works for individual intakes and makes for a wide engine.
Still unless you have VVT preferably on both I and E which requires a DOHC (see Chrysler Pentastar) you are going to have a torque curve with a peak and taper.
For the Crossfire this is at 3,000 rpm unlike my 3800s which peak at 2000. This may be the reason for such a short 6th but that is another matter.
In the early 60's Buick needed an "economy" engine which became the 231 V6 (several other sizes but this is the most common) and to further reduce startup costs and simplify tooling, it was a 90 degree V6 so it could use the same tooling as a V8.
From day one it vibrated. Soft engine mounts could not completely hide but big cars could absorb A Lot.
In the end the 231/3.8/3800 had a 40 year life and was the base of some of the fastest cars GM had built but in smaller chassis the vibration was too much so in 1978 they came up with the "evenfire" engine by using offset crank journals. In 1988 they added a balance shaft and my Reattae are very smooth. These are the basis of the L67 supercharged engine of drag fame.
An iron engine in an aluminum time it was replaced in 2004 by a more modern engine.
My point is that the 3.2 Crossfire engine is also a 90 degree V6 but I have seen no mention of an offset crank, just a balance shaft. I suspect this is why it is really being treated as two three cyl engines from an exhaust standpoint with separate pipes and catalysts & 240 degree separation instead of 150-90-150-90-150-90.
I have not taken a close look at the intake but suspect it is staggered. This uneven pulsing would also explain why people have had success with very large throttle bodies.
So meanwhile back at the ignition. That 150-90 business is easy for a computer but there are only six coils for 12 plugs amd firing is staggered so it is not a pure "lost spark" like Honda and Buick used.
Which makes me curious, just how many times do the plugs fire in a complete cycle and in what order ? YWTK (Suppose I'll need to rig up a scope to the ignition and see for myself but is an interesting problem.)
ps know this is long but putting down helps me to think about it and might find out if anyone has been here first, am still a newbie to Crossfires.