I have serval 2 cycle engines some are 47cc and others are 49cc. The
head and cylinder are made together I would like to know if there is a
simple and cheap way to check the volume of each engine with out
taking the cylinder off the engine.

Weigh them , they are bound to have a  different weight

You might try Ebay.com.  I know, what's ebay have to do with it??? 
See if you can find someone selling one of this two engines.  You may
find that the seller listed the cc.

if the 2 motors are from the same manufacturer, then it is assumable
that the head designs are similar. you could remove the spark plug and
manually rotate the crankshaft to where the piston is at it's bottom
most stroke and fill the head with oil, turn it upside down and drain
the oil into a measuring cup and then measure the amount of oil in
each size.

or use a compression tester screwed into the spark plug socket.  but
that would assume that the rings in all the motors are good.  the
larger would have more compression.