An Aid to Find Engine Top Dead Center
                    Ted Edwards <Ted_E@telus.net>

See also: T_D_Center_Finder.jpg

We need to check/set ignition timing on the Susuki snow mobile engine
for Ray's homebuilt biplane but there are no readily accessable timing
marks.  The manual says to use a dial gage through a spark plug hole but
the engine is mounted upside down on a test stand and there is no
reasonable way to mount a dial gage in a positive manner - a good excuse
to make a new tool!

I ground the outer electrode off an old spark plug and turned off the
crimp that retains the ceramic insulator and removed said ceramic.  I
then machined a piece of aluminum rod to be a press fit into the steel
shell of the spark plug and through drilled to accept the shank of a
dial gauge.  This sleeve was then cross drilled and tapped for a set
screw to retain the dial gauge.  The sleeve was then pressed into the
spark plug shell and our tool was ready to go to work.