1974 NASCAR International Stock Car Racing Rule Book NASCAR Grand National ® Championship Division Section 20-25 -- Fuel and Fuel Cells

a. Gasoline only as fuel. Fuel specifications as follows:

(1) The word "FUEL" shall wherever used in this document, be understood to mean Automotive Gasoline generally complying with United States Government Federal Specification VV-G-76A or B entitled "GASOLINE AUTOMOTIVE."

(2) Generally complying shall be interpreted to indicate any of the fuel classes A, B, C, D, or E but without the geographical or seasonal limitations imposed by VV-G-76A or B (VV-G-76B is identical to ASTM Standards D 439-70).

(3) With the exception noted in the preceding paragraph which permits fuel volatilities without geographical or seasonal limitations, all fuels shall conform to current FIA (Appendix "J" Article 297) and ACCUS rules.

(4) NASCAR reserves the right to have all cars use the same brand of gasoline.

b. Fuel cells mandatory. Fuel cell maximum capacity 22 gallons, including filler spout. Fuel cell must be encased in a NASCAR approved container (see diagram on rear pages of rule book) of no less than 20 gauge steel, divided into two compartments--a top half and bottom half--whose dimensions are as near equal as possible. Fuel cell must be fitted within the container so that the maximum capacity, including filler spout, will not exceed 22 gallons. Violation of this specification will call for immediate disqualification of car, plus a fine, and confiscation of illegal parts. The following are the only NASCAR approved fuel cell container sizes: 33 x 17 x 9, 31 x 20 x 8 1/8, 25 x 25 x 8 1/16. Any fuel cells not designed to fit these dimensions must be submitted for NASCAR approval thirty (30) days prior to date of intended use and fuel cell container sizes be established by the NASCAR Technical Director.

(1) Fuel cell and container must be fastened to the floor or recessed as shown in diagram on rear pages of Rule Book.

(2) Fuel cell must be installed as far forward as possible in trunk compartment equal distance between frame rails.

(3) Fuel cell, whether installed on trunk floor or in recessed well, must be secured with steel straps, not less than two lengthwise and two crosswise.

(4) When mounting fuel cell through trunk floor an additional container of minimum 20 gauge steel must be welded solid to floor of trunk for installation of fuel cell container. (See diagram on rear pages of Rule Book).

(5) No rags or stuffing permitted to make fuel cell meet 22 gallon capacity. Any materials used to bring fuel cell to 22 gallon capacity must be of steel and welded in.

(6) One 1-inch maximum vent to outside of body at left rear light. (Left hand fill only.) 1-inch drain pipe at filler neck spout. Check valve vent pipe neck inside diameter shall not exceed 1" maximum. Check valve filler neck inside diameter shall not exceed 2 1/8" maximum, 2 1/4 inches outside diameter. Filler cap must be located in left quarter panel at top of fender line, position approved by NASCAR. Maximum distance from top of filler neck to bottom of fuel cell pan shall not exceed 24". This is the only measurement required for fuel cell body height location and installation. Steel balls must be used in check valve assembly. NASCAR Technical Inspectors will reject any previously approved fuel cells, containers, or check valves which are damaged, defective, or do not function properly. Fuel cell vent pipe check valves are compulsory. Check valves and fuel cell must be approved by NASCAR.

(7) NASCAR approved dry coupling systems are mandatory.

(8) Either or both right or left side pickup in fuel cell may be used.

(9) All fuel cells must be equipped with removable drain plug; otherwise they will be removed for inspection.

(10) Fire wall of steel not less than 20 gauge thickness must go between trunk and driver.

(11) A rounded pan of 20 gauge steel is mandatory when the fuel cell container hangs down below the frame rails. This pan may be attached to the frame rails only and extend under the fuel cell container, but not beyond the rear frame cross member.

(12) Electric fuel pumps not permitted.

(13) No water cooling permitted on fuel pump.

(14) No additional lines may be used on fuel system.

(15) Fuel lines from cell to carburetor may be relocated to prevent vapor lock, but must remain under floor of car unless otherwise approved. Line may be replaced with neoprene hose not to exceed 1/2 inch I.D. Only one fuel line permitted from fuel cell to fuel pump. All fuel lines must be approved by NASCAR. Extra fuel lines or cells, concealed or otherwise, are prohibited.

(16) No pressure system allowed.

(17) Positively no electric motors permitted in trunk compartment.

(18) No icing or cooling of fuel permitted in garage, pit or racing area.

(19) Fuel cells become obsolete five years after date of manufacture and must be replaced. (See diagrams in rear pages of Rule Book for proper fuel cell installation.)

(20) Only two approved eleven (11) gallon fuel cans permitted in pits for refueling. (See diagram on rear pages of Rule Book.)