Approval Details

Valid E.O.


This Executive Order approved the specified parts on on September 28, 1979.
As of Sunday, September 22nd, 2019 this Executive Order has not been overturned or superceeded.

Approved Parts

1979 and older vehicles, EXCEPT: (1) 1977-1979 Chrysler and Porsche, (2) Chrysler lean burn, (3) Feedback systems vehicles, (4) Three-way catalyst vehiclesRetard timing 50% on pre-75 vehicles requiring premium fuel

This Executive Order may be listed as:
  • C.A.R.B.E.O. D-93
  • Executive Order 93 / D93
  • ARB # D-93
  • Executive Order No: D-93
  • C.A.R.B. No. D-93
  • Resolution D-93
For Free CARB Executive Order Status verification, email an image of the device Executive Order label as well as the Year/Make/Model and Test Group # of the vehicle to [email protected]

Download: Executive Order D-93 PDF

D-93 Document:

                                                                (Page 1 of 2)
                          State of California
                          AIR RESOURCES BOARD

                        EXECUTIVE ORDER D—93
              Relating to Exemptions under Section 27156
                    '     of the Vehicle Code

                        "SCOVER ENERGY SYSTEM"

Pursuant to the authority vested in the Air Resources Board by Section
27156 of the Vehicle Code; and

Pursuant to the aufhority vested in the undersigned by Sections 39515 and
39516 of the Health and Safety Code and Executive Order @—45—5;

IT IS ORDERED AND RESOLVED:   That the installation of the Scover Energy
System manufactured by Automotive Energy Systems, Inc. of 4827 N. Sepulveda
Bivd., Suite 410, Sherman Oaks, CA 91403 has been found to not reduce
the effectiveness of required motor vehicle pollution control devices
and, therefore, is exempt from the prohibitions of Section 27156 of the
Vehicle Code for 1979 and older gasoline powered vehicles except 1977—1979
Chrysier and Porsche vehicles, and engines equipped with the Chrysler
lTean burn system, feedback controls, or three—way catalysts.

This Executive Order is valid provided that installation instructions
for this device will not recommend tuning the vehicle to specifications
different from those submitted by the device manufacturer.

Changes made to the design or operating conditions of the device, as
exempted by the Air Resources Board, that adversely affect the per—
formance of a vehicle‘s pollution contro] system sha11 invalidate
this Executive Order.

Market1ng of this device using an identification other than that shown
in this Executive Order or marketing of this device for an application
other than those Tisted in this Executive Order shall be prohibited unless
prior approval is obtained from the Air Resources Board. Exemption
of a kit shall not be construed as an exemption to sell, offer for sale
or advertise any components of the kit as individual devices.

This Executive Order does not constitute any opinion as to the effect
that the use of this device may have on any warranty either expressed or
implied by the vehicle manufacturer.


"SCOVER ENERGY SYSTEM"                                         (Page 2 of 2)

No claim of any kind, such as "Approved by Air Resources Board" may be made
with respect to the action taken herein in any advertising or other oral
or written communication.

Section 17500 of the Business and Professions Code makes untrue or mis—
leading advertising unlawful, and Section 17534 makes violation punishable
as a misdemeanor.

Section 43644 of the Health and Safety Code provides as follows:

     "43644.   (a) No person shall install, sell, offer for sale, or
     advertise, or, except in an application to the state board for
     certification of a device, represent, any device as a motor vehicle
     pollution control device for use on any used motor vehicle unless
     that device has been certified by the state board. No person shall
     sell, offer for sale, advertise, or represent any motor vehicle
     pollution control device as a certified device which, in fact, is
     not a certified device. Any violation of this subdivision is a
     misdemeanor."                                                  j
Any apparent violation of the conditions of this Executive Order will be
submitted to the Attorney General. of California for such action as he
deems advisable.

Executed at El Monte, California, this       23&   day of September, 1979.

                                    . D. Drachand, Acting Chief         ~
                                   Mobile Source Control Division

                           State of California
                           AIR RESOURCES BOARD

                           September 27, 1979

                              Staff Report

        Evaluation of the Automotive Energy Systems, Inc. "Scover
        Energy System" in Accordance with Section 2222, Title 13
                  of the California Administrative Code


      Automotive Energy Systems, Inc. of 4827 N. Sepulveda Blvd, Suite

      410, Sherman Oaks, California 91403 has submitted an application

      for exemption of the Scover Energy System from the prohibitions

      of Section 27156 of the California Yehicle Code.

II.   System Description

      The Scover System is an exhaust gas recirculation device consisting

      of a reed valve mounted on the exhaust manifold and a flexible

      metal hose from the valve to a fitting on the air cleaner.    Ekhaust

      gas is metered through the valve and enters the clean side of the

      air cleaner above the carburetor inlet.    When the exhaust manifold

      is in a condition of negative gage pressure, the direction of flow

      is reversed and clean air is pulled into the exhaust manifold.

    Timing is specified at OEM setting except on pre—1975.vehicles

    requiring premium fuel where retard of 50% of the OEM value is

    recommended.   The applicant represents the device as recirculating

    approximately 1% of the total exhaust flow on vehicles with OEM

    EGR valves and 6% of the total flow on vehicles without EGR valves.

III. Applicants Submittal

    A.    Operating Principles

          According to the applicant, the Scover Energy System performs

          three major functions: exhaust gas recirculation, fresh air

          backflow to the exhaust manifold and cylinders, and high

          frequency oscillation of the intake air/fuel mixture.

          The effect of exhaust gas recirculation is to enrich the

          intake air/fuel mixture allowing adjustment of the carburetor

          and timing for increased fuel economy.   The exhaust gas re—

          circulation also preheats the mixture for better cold engine

          performance and increases engine life.

          The applicant also states that fresh air drawn into the

          exhaust manifold during the valve overlap period will

          scayenge residual exhaust gas in the cylinders and cause

          leaning of the air/fuel ratio to increase fuel ecornomy in

          certain operating modes.   This fresh air return also serves

          to relieve vacuum in the cylinders caused by deceleration.

High frequency sound wave oscillations from exhaust gas

pulses passing through small holes in the valve are conducted

to the carburetor inlet where AES, Inc. believes they

increase turbulence to aid in air/fuel vaporization and

mixing.    These oscillations are intended to improve burning

characteristics and increase fuel economy.

Benefit Claims

Automotive Energy Systems, Inc. claims that the Scover Energy

System will:

1)   increase fuel economy

2)   reduce emissions

3)   reduce engine wear
4)   reduce oil conéumption and carbon build—up

5)   allow use of regular grade fuel in vehicles that require

     premium grade

6)   increase performance

7)   allow better hot and cold starts


Automotive Energy Systems, Inc. submitted data as shown in

Table I.    The net percent changes from baseline are shown in


              Table 1 — Applicant‘s Emission Test Results

                                             HC        cCO      NOx           FE
    Vehicle              Test                g/mi      g/mi     g/mi          mi/gal

    1978 Honda      Baseline—cold CVS—II     0.53      5.03     1.43          26.23
    Civic CVCC,     Device—cold CVS—II       0.60      5.19     1.62          25 .36
    91 CID                                   (13%)     (3%)     (12%)         (—3.3%)

    1979 Chevrolet Baseline—cold CVS—II      0. 55     1.93      1.13         15.54
    305 CID        Device—cold CVS—1I        0.60      2.72      1.06         15. 34
                                             (9%)      (41%)     (—6%)        (—1%)
    1979 Cheyrolet Baseline HFET             0.04      0.0       1.43         21 .48
    305 CID        Device HFET               0. 04     0.0       1.38         21 .37
                                             (0%)      (0%)      (—3%)        (—1%)
    1968 Ford,      Baseline—cold CVS—II     3.06     23.19      4.59         14.69
    289 CID         Device—cold CVS—I1       3.08     23.19      3.70         14.87
                                             {(0%)     (0%)      (—19%)       (1%)

    1968 Ford       Baseline HFET            1.69      6.44      6.00         20.31
    289 CID         Device (4 holes) HFET*   1.71      7.07      5.26         20. 62
                                             (1%)      {10%)     {(—12%)      (2%)
                    Device (6 holes) HFET    1.80      8.14      4.68         20.83
                                             (7%)      (26%)     (—22%)       (3%)

         Additional data was presented on an Audi and a Buick using the
         Japanese 10—mode exhaust emissions test, and a 1972 Ford

         Mustang using the CVS—II.   The Audi and Buick are considered

         unacceptable test vehicles because their odometer mileage

          (1450 and 237 mfles respectively) indicates that they may not

         be stabilized with respect to emfssions and fuel economy.      The

         Mustang was tested with a defective carburetor, and is also
         considered unsuitable as a test vehicle.

*The Scoyer yalye is obtainable in various metering configurations to
 accommodate different engine sizes. The number of holes in the orifice
 plate controls the metering. A four hole plate is the proper size for a
289. CID engine.

IV.   Air Resources Board Testing

      The Air Resources Board (ARB) conducted a confirmatory test on a

      1974 Chevrolet Vega with a 140 CID, 4 cylinder engine.       The base—

      lTine tests were performed with the vehicie adjusted to vehicle

      manufacturer‘s specifications.      The device was installed according

      to the device manufacturer‘s instructions, except that timing was

      retarded as for a vehicle using premium grade fuel.       The Vega

      was designed for regular grade fuel, and the test results given

      in Appendix II are therefore not used in the evaluation.

      A retest was conducted on the same car at the correct (OEM) timing
      setting.   The results of the retest are presented below in Table 2.

                    Table 2 — ARB Emission Test Results

                                             HC        CO         NOx          FE
Vehfcle               Test                   g/mi      g/mi       g/mi         mi/gal

1974 Chey        Baseline — cold CVS—II      2.46      13.44       1.97        20.8
Vega, 140 CID    Device — cold CVS—II        2.01      13.98       1.85        20.6
                                             —18%       4%         —6%         —1%

1974 Chev        Baseline — HFET             1.04       3.07      7.60         26.7
Vega, 140 CID    Device — HFET               1.09       3.33      1.47         27.6
                                              5%       ~8%        =—8%          3%

      A filter was used on a hot start CVS—75 test to trap particulates

      and measure possible carburetor contamination.        The filter accumulated

      0.006 grams of particulates during the hot—start CVS—75 cycle, or

      approximately 0.0005 grams per mile with a total exhaust flow through

      the valve of 4.354 standard cubic feet (SCF) or approximately 0.392



 Evaluation of the emission data in table 1 shows a borderline
 (10—15%) tendency to increase emissions in the test vehicles.     The

 1979 Chevrolet shows a 41% increase in CO.   No significant

 increase in fuel economy is evident from any of the tests.

 The exhaust carries approximately 0.0005 grams of particulates per

 mile for the test vehicle.   This was measured by installing a

 fiberglass filter in the Scover valve line and weighing the filter
 before and after a hot—start CVS—II.   The amount of particulates

 is insignificant in this case, but could conceivably cause problems

 in vehicies which have Scover valves with higher rates of exhaust

_ gas recirculation to the air cieaner or poor engine condition.     OEM

 exhaust gas recirculation is a nominal 9—10 standard cubic feet per

 minute {SCFM) compared to. 4—5 SCF for the entire CVS—II cycle
‘through the Scover valve (approk. 31 minutes).   The amount of

 Scover recirculation in this vehicle is a small percentage of

 the OEM recirculation except that the Scover valve operates in all

 engine modes while an OEM valve does not.

 Adding inert exhaust gas to carburetor inlet air has the effect
 of causing enrichment of the air/fuel mixture which can only be

 slightly compensated for by adjusting idle mixture screws.    If the

 exhaust gas recirculatton is 15rge enough to reduce NOx then it
 could also be expected to decrease fuel economy and increase HC

    and CO.   The HC and CO effects of enrichment might be offset if

    the cylinders are scavenged as the applicant describes, but then

    the NOx could be expected to increase because the residual exhaust

    gases in the cylinders which act to lower NOx are removed.

    Under the conditions stated in an Executive Order, the AES, Inc.

    may not clatm reduced emissions.      Other claims such as increased

     fue? economy and performance have not been substantiated.     Some,

     claims appear to be contradictory.     For instance, timing retard

     and exhaust gas recirculation are known to reduce fuel economy

     and performance in most cases.

VI. ‘Recommendation

    The staff recommends that the Executive Officer exempt the Scover

     Energy System from the prohibitions of VC 27156 as no significant

     increase in emissions can. be documented.

         nc guuovelr   pnergy systeMm must Lo     anstuiled in a yertjeal fosition
        on   the   exhaust manifold.   (See   illustrations.)

                                       1}     Locate a suitable position on the exhau:
                                              manifold. Preferably, near where two
                                              exhaust ports join together and where
                                              the Scover Energy System can be mounted
                                              in a yvertical position.

                                              Note:    In some cases it may be necessary
                                                       to drill the manifold hole at a
                                                       nonvertical position, then use
                                                       adapter ({included in package) in
                                                       order to correctly mount the Scove
                                                       Energy System in a vertical positi
  STALLATIO    5   OLLEY                                     .                has         .
Jh%fifiL‘hfl    N_USING LLEW OR           2)     Aftcor   locating correct position,       drill
                5T CONVENIENT
          IS MOST       ENIENT .              a hole using a 7/16using
                                              exhaust manifold,
                                                                   .     bit in the
                                                                       grease as a

                                              lubricant to catch filings.           Tap the
                                              hole deep, using a 1/4 — 1% NPT tapered
                                              tap.   Start engine, part throttle, to bl
                                              out any remaining filings from manifold
                                              area.     ‘Turn engine off.

                                        3)    Turn the      lock nut to its top position
                                              on the male thread of the Scover unit.
                                              when     adapters are being   used,    install
                                              the adaptcr into the manifold making
                                              sure it is tight.  Install Scover unit
                                              into adapter and/or manifold hand
                                              tight.  Tighten lock nut to  secure
                                              Scover unit to adapter and/or



                                                     SIDE MANIFOLD INSTALLATION


                                  4)   Determinc the correct position on the:
                                       clean air side of the air filter housing

                                       Note: The clean air side is defined as
                                             being a position after the air has
                                             passed through the air filter
                                             cleaning element and is entering
                                             the carburetor.   If it   is imposs—
            4)                               ible to correctly install the tubi:
                                             to the top side of the air filter
Clean Alr Side                               housing due to insufficient hood
                                             clearance between the housing and
                                             the hood, the connection should
                                             be made to the underside of the
                                             housing.  If doubtful about the
                                             hood clearence, a check should be
                                             made by placing a lump of putty on
                                             the housing and closing the hood.
                    AIR CLEANER              Then measure the clearance availab.

                                             Drill a 7/16" hole at the selected
                                             position in the housing.  Tighten
                                             the tubing into place using lock
                                             nut that is provided on the

        Air Filter Connector — The lock nut on the inside of the air
        cleaner housing must be secured from any possibility of working

        Now the engine must be started and run until it has attained
        normal operating temperature.  Then, adjust to manufacturer‘s

            Note:    All enginc timing must remain set at manufacturer‘s
                     specifications with the   exception   listed below.

   6)   Engines manufactured prior to    1975 which require premium fuel
        can use regular fuel with the Scover Energy System by retarding
        timing 50% of value, i.e., manufacturer‘s specification 6° BTDC,
        set timing with Scover Energy System to 3° BTDC.

        Attach timing instruction label adjacent to the vehicle man—
        ufacturer‘s tune—up label in engine compartment.

Document Created: 2005-09-01 12:40:40
Document Modified: 2005-09-01 12:40:40

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