The following specifications for the 1971 Corvette LS6 engine come from Corvettes Technically Speaking, by Michael C. Harrison, 1st. Edition Limited, Copyright 1977. The technical information published in the book was released by GM on 9-29-1970. As more information becomes available to us, we will update these specifications.
| General | ||
|---|---|---|
| SAE Horsepower: | 425 bhp @ 5,600 rpm | |
| SAE Torque: | 475 ft. lbs @ 4,000 rpm | |
| Displacement: | 454 CID | |
| Bore and Stroke: | 4.251 in. x 4.0 in. | |
| Compression Ratio: Maximum: Nominal: |
10.1:1 9.0:1 |
|
| Camshafts | ||
| P/N: | 3904366 | |
| Casting No: | 3904366 | |
| Base Circle | NA | |
| Lobe Lift | NA | |
| Supplier | NA | |
| Connecting Rods | ||
| Length: | NA | |
| Crankcase | ||
| Description | NA | |
| Cylinder Head Volume: | 103.1 | |
| Deck Clearance: | .008 below block | |
| Deck Height | NA | |
| Head Gasket Thickness (Compressed): | .021 | |
| Head Gasket Volume: | 7.09 cc | |
| Min. Combustion Chamber Vol: | 103.1 | |
| Crankshaft | ||
| Material: | NA | |
| Cylinder Head | ||
| Casting Number: | 3994026 (Iron) - 3946074 | |
| Manufacturer: | NA | |
| Material: | Cast Iron | |
| Induction | ||
| Make / Type: | 1 x 4 bbl. Holley Carburetor | |
| Intake | ||
| Material: | Aluminum | |
| Model No. - Auto. Trans: | 3986196 | |
| Model No. - Man. Trans: | 3986195 | |
| Intake Manifold Cast. No: | NA | |
| Lifter Type: | Mechanical | |
| Rocker Arm Ratio: | 1.7:1 | |
| Pistons | ||
| Description: | Domed | |
| Displacement of Dish/Dome, etc: | 13.1 cc | |
| Height of Dome or Depth of Dish: |
.095 | |
| Manufacturer: | NA | |
| Material: | NA | |
| Timing | ||
| Check Cl: | Intake: .024 Exhaust: .028 |
|
| Opens: | Intake: 44o BTC Exhaust: 86o BBC |
|
| Closes: | Intake: 92o ABC Exhaust: 36o ATC |
|
| Overlap: | Intake: 80o Exhaust: |
|
| Duration: | Intake: 316o Exhaust: 302o |
|
| Lift: | Intake: .5197 @ 0 - lash Exhaust: .5197 @ 0 - lash |
|
| Springs | ||
| Outer Closed: | Intake: 75 +/- 6 @ 1.88 Exhaust: 75 +/- 6 @ 1.88 | |
| Outer Open: | Intake: 240 +/- 12 @ 1.38 Exhaust: 240 +/- 12 @ 1.38 | |
| Inner Closed: | Intake: 30 +/- 4 @ 1.78 Exhaust: 30 +/- 4 @ 1.78 | |
| Inner Open: | Intake: 90 +/- 9 @ 1.18 Exhaust: 90 +/- 9 @ 1.18 | |
| Valves | ||
| Head Diameter: | Intake: 2.195 Exhaust: 1.885 | |
| Angle of Seat & Face: | Intake: 46o & 45o Exhaust: 46o & 45o | |