I just got my engine rebuilt. When I was installing the plugs I saw that the diameter of the leading (top) spark plug hole gets much smaller (like the size of a pea) just past where the plug penetrates, whereas the diameter of the trailing plug stays the same diameter all the way through.

Is it suppose to be like that?

 

The top plug is the trailing.

GO TO SCHOOL AT:

http://www.rotaryengineillustrated.com/index.html


Observe the motion of the rotor in the housing and try to figure why the trailing hole is small.

 

Easy way to remember, Top Trailing, Lower Leading.
cvs