[Spridgets] Re;Re;[Spridgets ] Jag engine!

[Billy Zoom]

The crank, flywheel, pressure plate, and damper have to be balanced as a
unit by drilling or grinding a little here and there. Everything needs to be
indexed so it will always go together the same way. Then the rods have to
weight the same, but in the right places because part of their weight is
rotational and part is reciprocal. Then anything else that moves needs to
weigh the same. Some people are more OCD about this than others. A good
machinist "should" know what to take off where.
The same thing would be done to a 6cyl. or V12 if you're doing a serious
rebuild. You don't get to skip it because the design is inherently balanced.
Soave will chime in if I got any of that wrong.
BZ