If you're a Corvette Action Center forum member, you can login to the forums below. If you're not a member, you're welcome register here for free!


Supporting Vendors / Dealers - Advertising - Shop

Print Friendly and PDF



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