My 20+ years of experience as a car constructor and competitor, plus the expertise of our specialist technicians at GGR, is now available to you in a series of tips that we will regularly update, allowing you to advance your knowledge along with us.
This issue of Tip of the Pits is simply a listing of basic technical information to aid you as you work on your Cosworth.

Have Fun !
Graham.

Remember, the Golden Rule is,
"If you do not have the right equipment or experience, save yourself money and heartache and entrust the work to someone who does."

TIGHTENING TORQUES
Remember it is as important to ensure that bolts are not over tightened as under tightened.
Nmlb/ft
OIL DRAIN BUNG INTO SUMP21-2716-20
ALTERNATOR TO MOUNTING BRACKET18-2514-19
ADJUSTMENT STRAP TO ALTERNATOR18-2514-19
ALTERNATOR STRAP TO WATER PUMP18-2514-19
TIMING BELT COVER(ALL BOLTS)8-106-8
SECONDARY TO PRIMARY EXHAUST MANIFOLD(2WD)32-3624-27
TURBOCHARGER TO MANIFOLD40-4830-36
CAM CAP TO CYLINDER HEAD(M6)8-106-8
CAM CAP TO CYLINDER HEAD(M8)12-239-17
CAM PULLEY TO CAMSHAFT59-6344-47
CAMBELT TENSIONER RETAINING NUT40-4830-36
CRANKSHAFT PULLEY TO CRANKSHAFT122-13592-101
CAM COVER BOLTS10-158-11
CYLINDER HEAD(STRETCH BOLTS)
  • STAGE 1
  • STAGE 2
  • STAGE 3
  • STAGE 4

    • 20-25
    45-50
    +90deg
    +90deg
    15-19
    34-38


    CHECK TORQUE(IF BOLTS TURN-REPLACE THEM)11083
    SPARK PLUG TO CYLINDER HEAD(LUBRICATE THREADS)28-3321-25
    WHEEL NUTS10075

    OIL PRESSURE (ALL MODELS)
    MINIMUM OIL PRESSURE WHEN AT NORMAL OPERATING TEMPERATURE.
    IDLE SPEED1.8 BAR (26 PSI)
    2000 RPM2.4 BAR (35 PSI)

    FUEL PRESSURE (ALL MODELS)
    IDLE SPEED3.0 BAR (44 PSI)
    WITH PRESSURE PIPE REMOVED FROM REGULATOR 3.5 BAR (51 PSI)

    SPARK PLUGS
    There is a huge range of spark plugs that can be fitted to the Cosworth engine. Based on our experience, here are our recommendations:
    TYPEUSEELECTRODE GAP
    MOTORCRAFT AGPR 12PPSTANDARD SMALL TURBO ESCORT1.1 - 1.2mm (0.044" - 0.048")
    MODIFIED SMALL TURBO ESCORT0.86 - 0.9mm (0.034" - 0.036")
    MOTORCRAFT AGPR 12 PP8 (AS ABOVE BUT 0.8mm GAP STANDARD) STANDARD LARGE TURBO ESCORT1.1 - 1.2mm (0.044" - 0.048")
    STANDARD SIERRA COSWORTH0.7 - 0.8mm (0.028" - 0.032")
    MODIFIED COSWORTH SIERRA OR ESCORT (MAX. BOOST 1.6 BAR)0.7 - 0.8mm (0.028" - 0.032")
    MOTORCRAFT AGPR 902 P (COOLER RUNNING THAN AGPR 12 PP8)MODIFIED COSWORTH SIERRA OR ESCORT (MAX. BOOST 2.0 BAR)0.6 - 0.7mm (0.024" - 0.028")
    CHAMPION C 59 CCOMPETITION OR TRACK DAY COSWORTH (BOOST PRESSURE DEPENDANT)0,5 - 0.7mm (0.020" - 0.028")
    CHAMPION C 57 CAS ABOVE BUT FOR HARDER WORKING CONDITIONS (COOLER RUNNING PLUG)AS ABOVE

    TYRE PRESSURES
    FRONTREARUSE
    SIERRA COSWORTH
    205/50 VR 152.1 BAR(31 PSI)2.3 BAR(34 PSI)Normal load & speed
    2.3 BAR(34 PSI)2.5 BAR(37 PSI)Heavy load, Normal speed
    205/50 VR 152.3 BAR(34 PSI)2.5 BAR(37 PSI)Normal load, High speed
    2.6 BAR(38 PSI)3.0 BAR(44 PSI)Heavy load, High speed
    ESCORT COSWORTH
    225/45 ZR 162.0 BAR(29 PSI)2.2 BAR(32 PSI)Normal load & speed
    2.2 BAR(32 PSI)2.4 BAR(35 PSI)Heavy load, Normal speed
    2.2 BAR(32 PSI)2.4 BAR(35 PSI)Normal load, High speed
    2.5 BAR(37 PSI)2.9 BAR(43 PSI)Heavy load, High speed
    T125/80 R16 97M Emergency spare tyre - 4.2 BAR (62 PSI)

    PLEASE NOTE THAT AS A GENERAL RULE, INCREASES IN WHEEL DIAMETER REQUIRE A SMALL INCREASE IN PRESSURE [0.1 BAR (1.5 PSI) PER INCH], AND INCREASES IN TYRE WIDTH MAY REQUIRE A SMALL DECREASE IN PRESSURE.

    LUBRICATION RECOMMENDATIONS
    GEARBOX(2WD)AUTOMATIC TRANSMISSION FLUID2.55 LTRS(0-5mm BELOW PLUG)
    GEARBOX(4x4)DEDICATED MT75 TRANSMISSION OIL (SIMILAR TO AUTO TRANSMISSION OIL)1.2 LTRS(0-5mm BELOW PLUG)
    TRANSFER BOX(4x4)DEXTRON TYPE AUTO TRANSMISSION0.5 LTRS(18mm BELOW PLUG)
    ENGINE OILFULLY SYNTHETIC ENGINE OIL 5W/40 OR 15W/50NOMINAL CAPACITY 4 LTRS(3-6mm BELOW TOP MARK ON DIPSTICK)
    DIFFERENTIAL OIL75/90W SEMI/FULLY SYNTHETICNOMINAL CAPACITY 1 LITRE (0- 5mm BELOW PLUG)

    BRAKE DISC DETAILS

    DIAMETER    		ORIGINAL THICKNESSMINIMUM THICKNESS
    2 WHEEL DRIVE FRONT283mm24.15mm22.8mm
    2 WHEEL DRIVE REAR273mm10.3mm8.9mm
    4 WHEEL FRONT278mm24.15mm22.8mm
    4 WHEEL REAR273mm20.00mm18.0mm

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    Correspondence/Requests
    Sales Enquiries: sales@grahamgoode.com
    Technical Enquiries: tech@grahamgoode.com
    Tel: +44 (0)116 244 0080
    Fax: +44 (0)116 244 0140