Approval Details

Valid E.O.

Validity

This Executive Order approved the specified parts on on November 16, 1994.
As of Friday, December 14th, 2018 this Executive Order has not been overturned or superceeded.

Approved Parts

Part NumberModelsModification
TFS-314000011986 and older GM vehicles equipped with a 262-400 c.i.d.V8 small block engine.A 160 degree Fahrenheit thermostat is required for installation on all 1994-95 vehicle applications.

This Executive Order may be listed as:
  • C.A.R.B.E.O. D-369
  • Executive Order 369 / D369
  • ARB # D-369
  • Executive Order No: D-369
  • C.A.R.B. No. D-369
  • Resolution D-369
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-369 PDF

D-369 Document:



                                                      (Page 1 of 2)

                                State of California
                                AIR RESOURCES BOARD

                               EXECUTIVE ORDER D~369
                     Relating to Exemptions Under Section 27156
                                of the Vehicle Code

                              SUMMIT RACING EQUIPMENT
                            TWISTED WEDGE CYLINDER HEADS
Pursuant to the authority vested in the Air Resources Board by Section 27156
of the Vehicle Code; and

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

IT IS ORDERED AND RESOLVED:      That the installation of the Twisted Wedge
cylinder heads manufactured by Summit Racing Equipment of 565 Kennedy Road,
Akron, Ohio 44305, as described in Table 1 of this Executive Order, has been
found not to reduce the effectiveness of the applicable vehicle poltution
control system and, therefore, is exempt from the prohibitions of Section
27156 of the Vehicle Code for 1995 and older General Motors vehicles
equipped with a 262—400 c.i.d. V8 small block engine.

                                     Table 1
                                                            Chamber
Application                            P/N _          Material    Vol.      Valve Size
1986   & older     . 2                 TFS—31400001   Aluminum    63   cc   2.02"x1.6"
1987   &=newer —%5                     TFS—31400002   Aluminum    63   cc   2.02"x1l.6"
1986   & older Corvettes non LT—1      TFS—31400003   Aluminum    63   cc   2.02"xl.6"
1992   & older Corvettes LT—~1         TFS—31400004   Aluminum    63   cc   2.02"x1.6"
1986 & older    a    . /2              TFS—31400005   Aluminum    63 cc     2.02"x1.6"
1987 &—rgewee — 15                    TFS—31400006    Aluminum    63 cc     2.02"xi.6"

This Executive Order is valid provided that the installation instructions
for the Twisted Wedge cylinder heads will not recommend tuning the vehicle
to specifications different from those of the vehicle manufacturer. A 160
degree Fahrenheit thermostat is required for installation on all 1994 & 1995
vehicle applicattons.
Changes made to the design or operating conditions of the Twisted Wedge
cylinder heads as exempt by the Air Resources Board, which adversely affect
the performance of a vehicle‘s pollution control system shall invalidate
this Executive Order.

Marketing of the Twisted Wedge cylinder heads using any identification other
than that shown in this Executive Order or marketing of the Twisted Wedge
cylinder heads for an application other than those listed in this Executive
Order shall be prohibited unless prior approval is obtained from the Air
Resources Board.


SUMMIT RACING EQUIPMENT                            EXECUTIVE ORDER D—369
                                                   (Page 2 of 2)



This Executive Order does not constitute any opinion as to the effect the
use of the Twisted Wedge cylinder heads may have on any warranty either
expressed or implied by the vehicle manufacturer.

THIS EXECUTIVE ORDER DOES NOT CONSTITUTE A CERTIFICATION, ACCREDITATION,
APPROVAL, OR ANY OTHER TYPE OF ENDORSEMENT BY THE AIR RESOURCES BOARD OF
CLAIMS OF THE APPLICANT CONCERNING ANTI—POLLUTION BENEFITS OR ANY ALLEGED
BENEFITS OF SUMMIT RACING EQUIPMENT‘S TWISTED WEDGE CYLINDER HEADS.
No claim of any kind, such as "Approved by the Air Resources Board" may be
made with respect to the action taken herein in any advertising or other
oral or written communication.

Violation of any of the above conditions shall be grounds for revocation of
this Executive Order.     The order may be revoked only after ten day written
notice of intention to revoke the order, in which period the holder of the
order may request in writing a hearing to contest the proposed revocation.
If a hearing is requested, it shall be held within ten days of receipt of
the request and the order may not be revoked until a determination after
hearing that grounds for revocation exist.

Executed at El Monte, California, this (25          of Navember, 1994.




                                      R. B,/Summerfield
                                      Assifétint Division Chief
                                      Mobile Source Division


                            State of California
                            AIR RESOURCES BOARD




  EVALUATION OF SUMMIT RACING EQUIPMENT‘S TWISTED WEDGE CYLINDER HEADS FOR
EXEMPTION FROM THE PROHIBITIONS OF VEKICLE CODE SECTIQON 27156 IN ACCORDANCE
     WITH SECTION 2222, TITLE 13, OF THE CALIFORNIA CODE OF REGULATIONS




                               November 1994


                            State of California
                            AIR RESOURCES BOARD




 EVALUATION OF SUMMIT RACING EQUIPMENT‘S TWISTED WEDGE CYLINDER HEADS FOR
EXEMPTION FROM THE PROHIBITIONS OF VEKICLE CODE SECTION 27156 IN ACCORDANCE
     WITH SECTION 2222, TITLE 13, OF THE CALIFORNIA CODE OF REGULATIONS




                                     by
                           Mobile Source Division
                            9528 Telstar Avenue
                          E1 Monte, CA    91731—2990




(This report has been reviewed by the staff of the California Air Resources
Board and approved for publication. Approval does not signify that the
contents necessarily reflect the views and policies of the Air Resources
Board, nor does mention of trade names or commercial products constitute
endorsement or recommendation for use.)


          Summit Racing Equipment of 565 Kennedy Road, Akron, Ohio 44305, has

applied for an exemption from the prohibitions in Section 27156 of the

California Vehicle Code (VC) for their Twisted Wedge cylinder heads.        The
Twisted Wedge cylinder heads are designed for installation on applicable 1995

and older General Motors vehicles equipped with a 262—400 c.i.d. small block
engine.

          Summit Racing Equipment submitted a completed application and other

required information, as well as emissions test data performed at the Edelbrock

Corporation located in Torrance, California, demonstrating that their Twisted

Wedge cylinder heads do not have any adverse effect on emissions.

          Based on the submitted information, the staff concludes that the

Twisted Wedge cylinder heads will not adversely affect exhaust emissions on

those vehicles for which an exemption is requested.

          The staff recommends that Summit Racing Equipment be granted an

exemption as requested and that Executive Order D—369 be issued.


                                 TABLE OF CONTENTS


                                                           Page Number



SUMMARY
CONTENTS                                                        1i
I.        INTRODUCTION
II.       CONCLUSION
III.      RECOMMENDATION
IV.       TWISTED WEDGE CYLINDER HEAD DESCRIPTION
          DISCUSSION OF THE TWISTED WEDGE CYLINDER HEADS




                                         11


 ieooomc Mn
       WITH SECTION 2222, TITLE 13, OF THE   CALIFORNIA CODE OF REGULATIONS

I.      INTRODUCTION
        Summit Racing Equipment of 565 Kennedy Road, Akron, Ohio 44305, has

applied for an exemption from the prohibitions in Section 27156 of the
California Vehicle Code (VC) for their Twisted Wedge cylinder heads.      The

Twisted Wedge cylinder heads are designed for installation on applicable 1995

and older General Motors vehicles equipped with a small block V8 engine.

II.     CONCLUSIONS
        Based on the submitted information, the staff concludes that the
Twisted Wedge cylinder heads will not adversely affect exhaust emissions from

the applicable vehicles for which an exemption is requested.

III.    RECOMMENDATION
        The staff recommends that Summit Racing Equipment be granted an

exemption for their Twisted Wedge cylinder heads for installation on applicable

1995 and older General Motors vehicles equipped with a 262—400 c.i.d. small

block engine.   The staff also recommends that Executive Order D—369 be issued.

IV.     TWISTED WEDGE CYLINDER HEAD DESCRIPTION
        The Twisted Wedge cylinder heads have been specifically designed for

installation on applicable 1995 and older General Motors vehicles equipped with

a 262—400 c.i.d. small block engine.   The Twisted Wedge cylinder heads are sold

as a set and operate in conjunction with the original equipment manufacturer‘s

(OEM) emissions control system already certified with the stock engine.         A 160

degree Fahrenheit thermostat is required for installation on all 1994 & 1995

vehicle applications.
        The purpose of using Twisted Wedge cylinder heads, according to
                                       —1—


the manufacturer, is to increase the engine‘s overall performance which is

accbmp]ished by designing the cylinder head‘s valves to be at an angle rather

than the typical valve that is linear to the piston.      The manufacturer also

claims that the cylinder heads are manufactured using the finest materials

available along with labor intensive machining.      The intake and exhaust ports

are machined to match the gasket and manifold surfaces, thus eliminating

reversion at those junctures.     The interior surfaces of the ports have been

machined in the critical areas to reduce backpressure and maintain laminar

flow.   The valve seats are machined to provide optimum sealing and increased

flow.   The combustion chambers are polished to eliminate hot spots which could

cause detonation or pre—ignition.

        The following are the Twisted Wedge cylinder head‘s specifications:



                                                                Chamber
Application                           P/N            Material   Vol.      Valve Size



1986 & older                          TFS—31400001   Aluminum   63 cc     2.02"x1.6"
1987 & newer                          TFS—31400002   Aluminum   63 cc     2.02"x1.6"
1986 & older Corvettes non LT—1       TFS—31400003   Aluminum   63 cc     2.02"x1.6"
1992 & older Corvettes LT—1           TFS—31400004   Aluminum   63 cc     2.02"x1i.6"
1986 & older                          TFS—31400005   Aluminum   63 cc     2.02"x1.6"
1987 & newer                          TFS—31400006   Aluminum   63 ce     2.02"x1.6"


V.      DISCUSSION_OF THE TWISTED WEDGE CYLINDER HEADS
        Summit Racing Equipment, has requested that the Twisted Wedge cylinder

heads be exempted for 1995 and older General Motors vehicles equipped with the
applicable small block V8 engine.     A 1994 Chevrolet truck equipped with a 5.7L
                                            —2—


engine, certified to Tier 1 emission standards, was used as the test vehicle.

One CVS—75 Federal Test Procedures was performed on the vehicle with the
Twisted Wedge cylinder heads, part no. TFS—31400002, and a 160 degree

Fahrenheit thermostat installed.   Summit Racing Equipment performed emissions

testing at the Edelbrock Corporation‘s emissions test facility.

        Results of the exhaust emissions test performed at Edelbrock are shown

in Table 1.


                                     Table 1
                               CVS—75 TEST RESULTS
                                           NMHC      CO      NOx
                 Device w/ applied DFs     0.31     3.4      0. 93
                 Standards                 0.32     4.4      1.0
                 Difference               —0.01    —1.0     —0.07


        The CVS—75 emissions test results at Edelbrock indicate that the HC, CO
and NOx emissions of the vehicle, with the cylinder heads and thermostat

installed, are below the emission standards set for that engine family.     The

Air Resources Board did not conduct confirmatory testing to validate the

emission test results submitted by Summit Racing Equipment

        Summit Racing Equipment‘s Twisted Wedge cylinder heads are functionally

identical to the original equipment manufacturer‘s Twisted Wedge cylinder heads

except for its valve size and chamber volume.     A typical General Motors vehicle

uses a 1.94" intake valve and a 1.5" exhaust valve and stock chamber volumes in
the range of 67 to 76cc.   Summit Racing Equipment consolidated these variations

by designing their Twisted Wedge cylinder heads to be at the top end of the OEM
scale at 2.02" on the intake and 1.6" on the exhaust with the chamber volume at
63cc.   Test results confirmed that the change in Twisted Wedge cylinder head‘s
specifications do not cause any significant change in vehicle emissions.

        Summit Racing Equipment submitted all of the required information

fulfilled the requirements for an exemption.
                                         —3—



Document Created: 2005-09-01 12:40:25
Document Modified: 2005-09-01 12:40:25

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