High performance street/strip, needs 9:1 compression, 2500+ stall, intake, gears and headers, rough idle.
Designed to deliver an aggressive, hard-hitting exhaust note at idle, the Thumpr camshaft series from COMP Cams also delivers excellent horsepower gains and a broad torque curve. A perfect choice for muscle cars and street rods, the Thumpr series' early intake valve opening and long exhaust duration create optimum overlap for that race car idle. The Thumpr grinds all require an aftermarket torque converter and lower gear ratio to ensure the drivetrain always puts the engine in its powerband. Additionally, Thumpr camshafts typically deliver reduced vacuum at idle, making a vacuum canister, pump or hydroboost a requirement for vehicles running power brakes.
Designed to deliver an aggressive, hard-hitting exhaust note at idle, the Thumpr camshaft series from COMP Cams also delivers excellent horsepower gains and a broad torque curve. A perfect choice for muscle cars and street rods, the Thumpr series' early intake valve opening and long exhaust duration create optimum overlap for that race car idle. The Thumpr grinds all require an aftermarket torque converter and lower gear ratio to ensure the drivetrain always puts the engine in its powerband. Additionally, Thumpr camshafts typically deliver reduced vacuum at idle, making a vacuum canister, pump or hydroboost a requirement for vehicles running power brakes.
Application Summary:
| Year | Make/Model |
|---|---|
| 1987-1991 | Avanti II |
| 1991-1996 | Buick Commercial Chassis |
| 1987 | Buick Regal |
| 1991-1993 | Buick Roadmaster |
| 1990-1992 | Cadillac Brougham |
| 1992-1996 | Cadillac Commercial Chassis |
| 1993 | Cadillac Fleetwood |
| 1987-1994 | Chevrolet Blazer |
| 1988-1995 | Chevrolet C1500 |
| 1992-1995 | Chevrolet C1500 Suburban |
| 1987 | Chevrolet C20 |
| 1988-1995 | Chevrolet C2500 |
| 1992-1995 | Chevrolet C2500 Suburban |
| 1987-1998 | Chevrolet C35 |
| 1988-1995 | Chevrolet C3500 |
| 1987-1992 | Chevrolet Camaro |
| 1987-1993 | Chevrolet Caprice |
| 1997-1998 | Chevrolet Cargo Van |
| 1991-1994 | Chevrolet Commercial Chassis |
| 1987-1991 | Chevrolet Corvette |
| 1987 | Chevrolet El Camino |
| 1998 | Chevrolet Express 1500 |
| 1996 | Chevrolet Express 2500 |
| 1998 | Chevrolet Express 3500 |
| 1987-1995 | Chevrolet G10 |
| 1987-1995 | Chevrolet G20 |
| 1987-1996 | Chevrolet G30 |
| 1988-1995 | Chevrolet K1500 |
| 1992-1995 | Chevrolet K1500 Suburban |
| 1988-1995 | Chevrolet K2500 |
| 1992-1995 | Chevrolet K2500 Suburban |
| 1988-1995 | Chevrolet K3500 |
| 1987-1988 | Chevrolet Monte Carlo |
| 1987-1989 | Chevrolet P20 |
| 1987-1998 | Chevrolet P30 |
| 1987 | Chevrolet R10 |
| 1987-1988 | Chevrolet R10 Suburban |
| 1989-1991 | Chevrolet R1500 Suburban |
| 1987-1988 | Chevrolet R20 |
| 1987-1988 | Chevrolet R20 Suburban |
| 1989-1991 | Chevrolet R2500 Suburban |
| 1987-1988 | Chevrolet R30 |
| 1989-1991 | Chevrolet R3500 |
| 1995-1998 | Chevrolet Silverado |
| 1987-1994 | Chevrolet Suburban |
| 1995-1998 | Chevrolet Suburban 1500 |
| 1995 | Chevrolet Tahoe |
| 1987 | Chevrolet V10 |
| 1987-1988 | Chevrolet V10 Suburban |
| 1989-1991 | Chevrolet V1500 Suburban |
| 1987 | Chevrolet V20 |
| 1987-1988 | Chevrolet V20 Suburban |
| 1989-1991 | Chevrolet V2500 Suburban |
| 1987-1988 | Chevrolet V30 |
| 1989-1991 | Chevrolet V3500 |
| 1993 | Excalibur Limited |
| 1987-1989 | Excalibur Phaeton |
| 1988-1995 | GMC C1500 |
| 1992-1995 | GMC C1500 Suburban |
| 1988-1995 | GMC C2500 |
| 1992-1995 | GMC C2500 Suburban |
| 1988-1995 | GMC C3500 |
| 1987 | GMC Caballero |
| 1987-1995 | GMC G1500 |
| 1987-1995 | GMC G2500 |
| 1987-1996 | GMC G3500 |
| 1987-1991 | GMC Jimmy |
| 1988-1995 | GMC K1500 |
| 1992-1995 | GMC K1500 Suburban |
| 1988-1995 | GMC K2500 |
| 1992-1995 | GMC K2500 Suburban |
| 1988-1995 | GMC K3500 |
| Attributes | |
| Advertised Exhaust Duration | 311, 311 |
| Advertised Intake Duration | 291, 291 |
| Amazon ASIN | B002EDZVUU |
| ASIN | B002EDZVUU |
| Assembly Lubricant Included | No, No |
| Basic Operating RPM Range | 1,900-5,600, 1,900-5,600 |
| C.A.R.B. E.O. Number | N/A |
| C.A.R.B. Exempt for Foreign Vehicles Manufactured Before 1967? | Yes, but must meet tailpipe emission standards for year of vehicle. |
| C.A.R.B. Exempt for On-Road Vehicles? | No |
| C.A.R.B. Exempt for Racing and Off-Road Only Vehicles? | Yes, but must be a race/competition only vehicle. |
| C.A.R.B. Exemption Reason | N/A |
| California Proposition 65 | WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov |
| Cam and Lifter Kit Upgrade | CL08-601-8, CL08-601-8 |
| Cam Type | Hydraulic Roller, Hydraulic Roller |
| Cam, Lifter and Gear Drive Upgrade | GK08-601-8, GK08-601-8 |
| Camshaft Gear Attachment | 3-Bolt, 3-Bolt |
| Camshaft Material | Austempered Ductile Iron, Austempered Ductile Iron |
| Camshaft Series | Thumpr, Thumpr |
| Country of Origin (Primary) | US |
| Emission Code | Not in CA |
| Engine Family | Chevrolet 305-350 c.i. 8 Cylinder O.E. Roller (1987-1998), Chevrolet 305-350 c.i. 8 Cylinder O.E. Roller (1987-1998) |
| Engine Make/Size | Chevy Small Block (262-400) |
| Exh. Duration @ .050 in. (Deg) | 249 |
| Exh. Duration Advertised (Deg) | 311 |
| Exhaust Duration at .050 inch Lift | 249, 249 |
| Exhaust Valve Lift | 0.509, 0.509 |
| Exhaust Valve Lift (in.) | 0.509 |
| Grind Number | 291THR7, 291THR7 |
| Harmonized Tariff Code (Schedule B) | 8409914000 |
| Hazardous Material Code | N |
| Int. Duration @ .050 in. (Deg) | 235 |
| Int. Duration Advertised (Deg) | 291 |
| Intake Duration at .050 Inch Lift | 235, 235 |
| Intake Valve Lift | 0.522, 0.522 |
| Intake Valve Lift (in.) | 0.522 |
| K-Kit Upgrade | K08-601-8, K08-601-8 |
| Life Cycle Status Code | Available to Order |
| Lifter Style | Hydraulic Roller |
| Lifter Type | Hydraulic Roller Retrofit, Hydraulic Roller |
| Lifters Included | No, No |
| Lobe Separation | 107, 107 |
| NAFTA Preference Criterion Code | B |
| RPM Range | 1900-5600 |
| SDR Required Flag | N |
| SDS Sheet Number | N/A |
| Usage | Street/Strip, Street/Strip |
| Valve Springs Required | Yes, Yes |
| Warranty Time | 12 |
| GTIN | 00036584171980 |