In reply to Pete. (l33t FS) :
You know what they say about assumptions....
I think it is probably safest to stick to describing the specific thing you are talking about, instead of assuming that independent but related things can stand in for each other, especially once the conversation strays away from V-8s. My understanding is that "even firing" means even firing, and that "flat plane" means all the crank throws in one plane. For V-8s/inline fours, cross plane and flat plane are useful and accurate, and it is probably best to describe crank design in terms of angle between throws with other engine configurations...for the sake of that certain type of person...not that I am one of those...
