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Specifications
Cosworth DFV (Dual Four Valve)
Introduced in 1968
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Dimensions
Cylinders arrangement: V8 (90o)
Strokes: 4
Bore x Stroke: 86.674 mm x 64.8 mm, 3.412" x 2.551"
Capacity: 2993cc, 186.6ci
Compression ratio: 11.5:1 or 11.0:1
Construction materials
Aluminium alloy block with cast iron cylinder wet liners, 104.1 mm bore spacing, 165.2 mm deck height
cast Aluminium alloy cylinder-head Central spark plug in pent-roof combustion chamber
flat-plane forged nitrided steel crankshaft with 5 main bearings 60.3 mm diameter, 49.2 mm rod bearing diameter (Flat plane/Cross plane)
Steel connecting rod length center to center 132.842 mm,
aluminium piston with 37.3 mm compression height, top ring 0.8 mm, middle 1.04 mm, oil 4.06 mm
Cylinder-head
Dual overhead camshafts (DOHC), gear driven
4 valves / cylinder - 32 valves total
intake valves inclination 16° from cylinder axis, exhaust valves inclination 16° from cylinder axis, 32° included angle
Intake valves diameter, 34.5 mm, with 38 mm center lines distance
exhaust valves diameter, 29.0 mm, with 34 mm center lines distance
valves stem, 7.14 mm
Aspiration
Natural with Lucas Mark II mechanical fuel injection
Ignition
natural aspiration with Lucas OPUS (Oscillating Pick-Up System) electronic (thyristor) ignition with conventional distributor with Autolite PG 403 or Champion G56R (10 mm)
Firing order, 1-8-3-6-4-5-2-7
Cylinder configuration:
Front
5-1
6-2
7-3
8-4
rear
Cooling and lubrication
Water cooled
Dry sump
Torque values
| Main bearing stud nuts (6 external) | 68 Nm Initially for seating, then 58 to 61 Nm on final assembly (Note: the six external main-bearing stud nuts (on the sump bottom for main bearings #1, #3 and #5) should be tightened to a "seating torque", then backed off to release all torque, and finally re-tightened to the specified assembly torque.) |
| Main Cap Stud Nuts (on Tapered Dowel Type Studs) | 58 to 61 Nm |
| Main Cap Side Stud Nuts 5/16" | 18 to 19 Nm |
| Main Cap 7/16" UNC screws | 72 to 75 Nm |
| Main Cap Side 5/16" UNC screws | 24 to 27 Nm |
| Connecting Rod Bolts | 56 to 57 Nm Anti-seize compound should be used under head of bolt, and engine oil on the threads |
| Cylinder Block Side Stud Nuts | 18 to 19 Nm, cadmium plated |
| Sump Side Plate 10-32 UNF screws | 34 Nm, use Loctite B under head |
| Cylinder Head Stud Nuts | 65 to 68 Nm |
| Cylinder Head Side Stud Nuts | 18 to 19 Nm, cadmium plated |
| Cam Cap Stud Nuts | 18 to 19 Nm |
| Cam Carrier Cover Stud Nuts | 22 to 24 Nm |
| Cam Cover 10-32 UNF Screws | 43 to 47 Nm |
| Flywheel Bolts | 72 to 75 Nm |
| Clutch Bolts | 18 to 20 Nm |
| Front Engine Mounting 5/16" Screws | 24 to 27 Nm |
| Front Engine Mounting 3/8" Screws | 46 to 49 Nm |
| Metering Unit Outlet Banjo Bolts | 122 to 136 Nm |
| Injectors | 8 Nm |
| Spark Plugs | 12 Nm, use graphite grease under head and on thread |
| Oil Filter Bowl | 5 to 8 Nm after initial tightening to 14 Nm and slackening |
| Mechanical Fuel Pump Check Valve Housing | 11 Nm |
| Alternator Drive Quill | 41 to 43 Nm, use Loctite A under head and on threads |
| All ¼" UNC Socket Head Cap Screws | 62 to 65 Nm |
| Engine mountings | The top mounting 5/16" UNF bolts should have washers (part number DA 0017) against the magnesium cover, carefully tightened to 22 to 24 Nm to avoid collapsing the magnesium alloy. |
| On lower mounting points, flat washers of .060" (1/16") min thickness must be used under the chassis bolt heads. | |
| The lower front mounting is marked "RT" (right top). If the lower front mounting is removed, it should be replaced with the letters "RT" towards the top of the engine. | |
| See also drawing numbers DA 0662 and DA 0774 |
Engine oil on thread and under the head, unless otherwise stated.
Models used and Output
| Year | Model | Induction | Compression ratio | Power | Torque |
|---|---|---|---|---|---|
| 1968 | Ford F3L P68 | Lucas Mk I | 11.5:1 | 420 HP / 313 KW @ 9000 rpm | 366 Nm / 270 ft lbs @ 7000 rpm |
| 1970 | McLaren M8C | Lucas Mk II | 11.5:1 | 420 HP / 313 KW @ 9000 rpm | 366 Nm / 270 ft lbs @ 7000 rpm |
| 1971 | Ligier JS2 | Lucas Mk II | 11.0:1 | 420 HP / 313 KW @ 9000 rpm | 366 Nm / 270 ft lbs @ 7000 rpm |
| 1971 | Ligier JS3 | Lucas Mk II | 11.0:1 | 420 HP / 313 KW @ 9000 rpm | 366 Nm / 270 ft lbs @ 7000 rpm |
| 1972 | Lola T280, S12 | Lucas Mk II | 11.0:1 | 445 HP / 332 KW @ 10500 rpm | 339 Nm / 250 ft lbs @ 8500 rpm |
| 1972 | Mirage M6, S12 | Lucas Mk II | 11.0:1 | 445 HP / 332 KW @ 10500 rpm | 339 Nm / 250 ft lbs @ 8500 rpm |
| 1973 | Lola T282, S12 | Lucas Mk II | 11.0:1 | 445 HP / 332 KW @ 10500 rpm | 339 Nm / 250 ft lbs @ 8500 rpm |
| 1974 | Mirage GR7, S12 | Lucas Mk II | 11.0:1 | 445 HP / 332 KW @ 10500 rpm | 339 Nm / 250 ft lbs @ 8500 rpm |
| 1975 | Ligier JS2 S12 | Lucas Mk II | 11.0:1 | 460 bhp / 343 KW @ 10200 rpm | 338 Nm / 249 ft lbs @ 8000 rpm |
| 1975 | Mirage GR8 | Lucas Mk II | 11.0:1 | 375 HP / 280 KW @ 9000 rpm | |
| 1976 | Lola T286, S12 | Lucas Mk II | 11.0:1 | 445 HP / 332 KW @ 10500 rpm | 339 Nm / 250 ft lbs @ 8500 rpm |
| 1978 | Rondeau M378 | Lucas Mk II | 11.0:1 | 460 bhp / 343 kW @ 10300 rpm | 324 Nm / 239 ft lbs @ 8300 rpm |
| 1979 | Rondeau M379 | Lucas Mk II | 11.0:1 | 460 bhp / 343 kW @ 10300 rpm | 324 Nm / 239 ft lbs @ 8300 rpm |
| 1981 | Lola T600, S12 | Lucas Mk II | 11.0:1 | 465 HP / 342 KW @ 10500 rpm | 339 Nm / 250 ft lbs @ 8500 rpm |
| 1982 | Rondeau M382, S12 | Lucas Mk II | 11.0:1 | 465 HP / 342 KW @ 10500 rpm | 339 Nm / 250 ft lbs @ 8500 rpm |
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