1967 - 1969 L88 Corvette Engine Specifications
The following specifications come from a wide variety of resources. Because there has'nt been a lot of information published on the L88 engines over the years, it was difficult to take the bits and pieces we had from various sources and compile them into an easy to follow summary. Due to variations in the reported numbers between these resources, we cannot guarantee the accuracy of the information reported.
You will notice that in some cases, a specific piece of data is blank. We simply left the space blank because it was data that we did not have. As more information becomes available to us, we will update these specifications.
| 1967 - 1969 L88 Corvette Engine Specifications | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1967 | 1968 | 1969 | ||||||||||
| General | ||||||||||||
| SAE Gross Horsepower (advertised): | 430 hp @ 5,200 rpm | |||||||||||
| SAE Net Torque (advertised): | 460 ft. lbs @ 4,000 rpm | |||||||||||
| SAE Gross Horsepower (actual): | Approx. 550 - 570 hp @ 6,200 - 6,400 rpm | |||||||||||
| SAE Net Torque (actual): | Approx. 470 ft. lbs @ 5,200 rpm | |||||||||||
| Displacement: | 427 CID, 6997 cc | |||||||||||
| Bore and Stroke: | 4.251 in. x 3.760 in. (108.0 x 95.2 mm) | |||||||||||
| Compression Ratio: Maximum: Nominal: |
12.8:1 12.5:1 |
12.9:1 12.0:1 |
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| Camshafts | ||||||||||||
| P/N: | 3928911 | 3928911 | ||||||||||
| Casting No: | 3928911 | 3928911 | ||||||||||
| Base Circle | 32.8 mm (1.291 in.) | NA | NA | |||||||||
| Lobe Lift | 9.9 mm (0.39 in.) | NA | NA | |||||||||
| Supplier | GM Bay City | NA | NA | |||||||||
| Connecting Rods | ||||||||||||
| Length: | 6.135" | NA | NA | |||||||||
| Crankcase | ||||||||||||
| Descriptions | Open deck 4-bolt fastening per bearing panel | |||||||||||
| Cylinder Head Volume: | 103.3 | 114.8 | ||||||||||
| Deck Clearance: | .008 | |||||||||||
| Deck Height | 9.800 in. | |||||||||||
| Head Gasket Thickness (Compressed): | .043 | |||||||||||
| Head Gasket Volume: | 10.81 cc | |||||||||||
| Min. Combustion Chamber Vol: | 74.15 cc | 73.47 cc | ||||||||||
| Crankshaft | ||||||||||||
| Material: | Forged premium alloy 5140 steel with "tuftride" surface coating | |||||||||||
| Cylinder Head | ||||||||||||
| Casting Number: | 3919842 | 3946074 | ||||||||||
| Manufacturer: | Winters Foundry | NA | NA | |||||||||
| Material: | Aluminum - (Early prototypes used cast iron) | |||||||||||
| Induction | ||||||||||||
| Make / Type: | 850 CFM Holley 1 x 4 bbl. D.D. | |||||||||||
| Material: | Aluminum | |||||||||||
| Model No. - Auto. Trans: | NA | NA | 3955205 | |||||||||
| Model No. - Man. Trans: | 3925519 | 3955205 | ||||||||||
| Intake Manifold Cast. No: | 3885069 or 3933198 | 3933198 | ||||||||||
| Lifter Type: | Mechanical - Solid | |||||||||||
| Rocker Arm Ratio: | 1.70:1 | 1.70:1 | ||||||||||
| Pistons | ||||||||||||
| Description: | dome head valve cutout | |||||||||||
| Displacement of Dish/Dome, etc: | 45.7 cc | 51.7 cc | ||||||||||
| Height of Dome or Depth of Dish: |
.454 | .454 | ||||||||||
| Manufacturer: | TRW | NA | NA | |||||||||
| Material: | High-silicon-alloy aluminum | NA | NA | |||||||||
| Timing | ||||||||||||
| Check Cl: | Intake: .020 Exhaust: .020 |
Intake: .020 Exhaust: .020 |
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| Opens: | Intake: 61o BTC Exhaust: 108o BBC |
Intake: 61o BTC Exhaust: 108o BBC |
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| Closes: | Intake: 113o ABC Exhaust: 72o ATC |
Intake: 113o ABC Exhaust: 72o ATC |
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| Overlap: | Intake: 133o Exhaust: |
Intake: 133o Exhaust: |
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| Duration: | Intake: 332o Exhaust: 333o |
Intake: 354o Exhaust: 360o |
Intake: 354o Exhaust: 360o |
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| Lift: | Intake: .560 @ .024 - lash Exhaust: .580 @ .026 - lash |
Intake: .540 @ .022 - lash Exhaust: .560 @ .024 - lash |
Intake: .540 @ .022 - lash Exhaust: .560 @ .024 - lash |
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| Springs | ||||||||||||
| Outer Closed: | Intake: 77 @ 1.88 Exhaust: 77 @ 1.88 | |||||||||||
| Outer Open: | Intake: 190 @ 1.344 Exhaust: 195 @ 1.324 | |||||||||||
| Inner Closed: | Intake: 43 @ 1.78 Exhaust: 43 @ 1.78 | |||||||||||
| Inner Open: | Intake: 100 @ 1.244 Exhaust: 103 @ 1.244 | |||||||||||
| Valves | ||||||||||||
| Head Diameter: | Intake: 2.19 Exhaust: 1.88 | |||||||||||
| Angle of Seat & Face: | Intake: 45o Exhaust: 45o | |||||||||||
References:
- Automobile Quarterly, Third Quarter 1990, Volume 28, Number 3, pg. 322-333
- Best of Vette Vues Magazine, Volume One-Nine, May 1981
- Corvettes Technically Speaking, by Michael C. Harrison, 1st. Edition Limited, Copyright 1977