A guy started this on our local forum. I searched to see if it had been done before but came up with nothing.
Basically just count the number of cylinders of things you own. Cars can be non running. This also includes watercraft, yard equipment, etc.
For Rotors..... Total Piston Count / Rotors = Total

Stuff I currently own
2005 gto - 8
1999 dodge 3500 - 6
1991 mr2 - 6

1988 rx7 - 8
1974 MB 280c - 6
2007 Sea-doo 215hp -3
honda pressure washer - 1
Generator - 1
Total = 39
Between my dad and I we have
120 at one house.