[Code of Federal Regulations]
[Title 40, Volume 22]
[Revised as of July 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR205.153]

[Page 130]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 205--TRANSPORTATION EQUIPMENT NOISE EMISSION CONTROLS--Table of Contents
 
                         Subpart D--Motorcycles
 
Sec. 205.153  Engine displacement.

    (a) Engine displacement must be calculated using nominal engine 
values and rounded to the nearest whole cubic centimeter, in accordance 
with American Society for Testing Materials (ASTM) E 29-67.
    (b) For rotary engines, displacement means the maximum volume of a 
combustion chamber between two rotor tip seals minus the minimum volume 
of that combustion chamber between those two rotor seals times three 
times the number of rotors.

cc=(Maximum chamber volume-minimum chamber volume) x 3 x number of 
          rotors.