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.
Fits '87+ GEN 1 Chevrolet 305-350 Small Blocks w/ Factory Roller Camshafts (Not LT-1/LS1 etc)
Notes- Fits only 1987 and newer blocks that have provisions (spider tray) for a roller camshaft.
Documents
Attributes
Camshaft Series: | Thumpr |
Usage: | Street/Strip |
Cam Type: | Hydraulic Roller |
Grind Number: | 291THR7 |
Basic Operating RPM Range: | 1,900-5,600 R3 |
Intake Duration at .050 Inch Lift: | 235 DD |
Exhaust Duration at .050 inch Lift: | 249 DD |
Advertised Intake Duration: | 291 DD |
Advertised Exhaust Duration: | 311 DD |
Lobe Separation: | 107 DD |
Intake Valve Lift: | 0.522 IN |
Exhaust Valve Lift: | 0.509 IN |
Valve Springs Required: | Yes |
Camshaft Gear Attachment: | 3-Bolt |
Camshaft Material: | Austempered Ductile Iron |
Engine Family: | Chevrolet 305-350 c.i. 8 Cylinder O.E. Roller (1987-1998) |
Cam, Lifter and Gear Drive Upgrade: | GK08-601-8 |
Cam and Lifter Kit Upgrade: | CL08-601-8 |
California Proposition 65: | WARNING: Cancer and Reproductive Harm P65Warnings.ca.gov |
K-Kit Upgrade: | K08-601-8 |
Lifter Type: | Hydraulic Roller |
Title: | Mutha' Thumpr 235/249 Hydraulic Roller Cam for OE Roller SBC |
Amazon ASIN: | B002EDZVUU |
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. Exempt for Federally Certified Vehicles Manufactured Before 1967?: | Yes, but must meet tailpipe emission standards for year of vehicle. |
C.A.R.B. Exempt for California Certified Vehicles Manufactured Before 1965?: | Yes, but must meet tailpipe emission standards for year of vehicle. |
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. Exemption Reason: | N/A |
C.A.R.B. E.O. Number: | N/A |
Package Information
Orderable Status:YesQuantity:1Package UOM:Smallest Pack (Consumer Level)Package Level GTIN:00036584171980Package Bar Code:036584171980Weight Variance:0.000000000Stacking Factor:0Inner Quantity:1 Each
Extended Information
Core Return Days to Expiry:0Country of Origin (Primary):USEmission Code:Not in CAHarmonized Tariff Code (HTS):8409914000Harmonized Tariff Code (Schedule B):8409914000Life Cycle Status Code:Available to OrderLife Cycle Status Description:Available to OrderMSDS Required Flag:NoMSDS Sheet Number:N/ANAFTA Preference Criterion Code:Criteria BNational Popularity Code:Top 60% of Product Group Sales Value (Units x $, Hits, etc.)National Popularity Description:Top 60% of Product Group Sales Value (Units x $, Hits, etc.)OEM’s Part Number:NOriginal Equipment Manufacturer:NOriginal Supplier:NOriginal Supplier Part Number:NPart Number – Old:N/APart Number Superseded To:N/ARefurbished Part:NoRemanufactured Part:NoStock Status:Shelf StockTaxable:YesWarranty Time:12Warranty Time UOM:Month