It is accepted that a horizontally opposed engine is called a boxer and an engine with <180degrees between banks is called a "V" engine. But to people who design multi cylinder engines the definition between a Boxer (flat) and 180 degree V is that for an engine to be calleda boxer the conrods each have their own crank journal, anda vee engine typically the pistons of each bank share a journal.
Using a 180degee V the sharing of crank journals allows for a shorter crankshaft and therfore a shorter engine.

So e.g. the Zundap, which was a 170degree V twin engine, the pistons shared one common crank journal. They built a 180 degree V as well but it was a little too long so reduced the angle to 170 to reduce the length of the engine. I believe it was mounted transvers in the bikes frame i.e. with the flywheel in the same axis as the wheels.
Seems a game of semantics but a 180 degree Vee engine has been built by Mercedes Benz in 1991 or 92 when they raced the World Sportscar championship with such an engine; 180 degrees layout but conrods from opposing cyclinder bankssharing crank journal's.

When the VWBeetle was designed the engine was called a "boxer" because it was designed as 4 separate single cyclinder engines in one crankcase. Each cyclinder was designed to produce a different power output. Usually an engine designer wants to ensure equal output per cyclinder.

With a two stroke it is not so critical if the journals are shared or not. You either get two bangs one after the other or two together. The two together with a separate journals resuklts in a longer crank with larger rocking couple. If sharing a journal typicall you have a shorter crank with less rocking couple. But on small two strokes is it important? Depand on the design

But it is the Indian GPthis weekend and friend and Iwere talking late last night about engine rules changes for 2014 and he mentioned the Mercedes 180degree V and how compromised the layout was. So anyway we were stil debating on the merrits of that definition but he havingworked forthat manufacturer in engine testing at the time of its development, was very clear onwhatthe differenceis.</p>