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COMP Cams CL51-233-4 - Comp Cams 'Magnum' Hydraulic Flat Tappet Camshafts

COMP Cams CL51-233-4 - Comp Cams 'Magnum' Hydraulic Flat Tappet Camshafts
COMP Cams CL51-233-4 - Comp Cams 'Magnum' Hydraulic Flat Tappet Camshafts
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JEGS Part Number: 249-CL51-233-4

Magnum 270H Hydraulic Flat Tappet Camshaft and Lifter Kit
Lift: .476''/.476"
Duration: 270°/270°
RPM Range: 1800-5800
  • Fits Applications:
  • 1977-1980
  • Click to see All

COMP Cams CL51-233-4 Details

Pontiac 265-455ci V-8 1955-81

Fair idle, good mid-range torque. Can use stock torque converter. Daily performance use.

Operating Range:1800-5800 RPM
Duration Advertised:270° Intake / 270° Exhaust
Duration @ .050'' Lift:224° Intake / 224° Exhaust
Valve Lift w/1.5 Rockers:.476'' Intake / .476'' Exhaust
Lobe Separation Angle:110°

Comp Cams 'Magnum' Hydraulic Flat Tappet Camshafts

Comp Cams Magnum Camshafts are very aggressive and specifically designed for the street enthusiast looking for more power with that Pro Street sound. Intended for performance oriented vehicles that will see little street use. The idle characteristics of your engine will change due to the increased duration and overlap of the Magnum Cam Series. You will notice a racey idle with the 280-grind while the 292 and 305-grinds will produce a rough or ''rumbly'' idle. Stock components are generally incompatible. Changes are needed in rear end gear ratios, headers and the torque converter. Magnum Cams will affect your power accessories to a certain extent. The 280 and 292-grinds are the biggest cams that should be used with power assisted brakes, air conditioning, etc. You should remember that the bigger the engine is, the less the cam will affect the vacuum which affects your power accessories. The smaller your engine is, the more the Magnum Camshaft will affect your power accessories. Most late model vehicles have a vacuum canister. If your vehicle does not have a vacuum canister, it may be necessary to add one.

  • Great high RPM power
  • Easy on valve train parts
  • Can be used with mild ratio rocker arms and traditional performance valve springs
  • Best with aftermarket converter and 9.5:1+ compression

    268H Series
    Good street performance with stock converter, choppy idle.

    270H Series
    Great for high performance driving in street machines. The 270H has a rough idle in small blocks and a noticeable idle in big blocks. This is the largest cam that can be used with a stock torque converter. The 270H should not affect power accessories, but should be used with headers and 4bbl carburetor.

    280H Series
    Best for serious street machines. This cam has a definite rough idle and will sometimes affect power accessories. It can be driven extensively on the street or raced on the weekends. The 280H needs an aftermarket converter, intake manifold and headers.

    286H Series
    Designed to fill in the gap between teh 280H and 292H. For serious street machines and bracket racers. With a rough idle and lower vacuum signal, this is not an average street cam. At least a 2500-RPM converter must be used, but a 3000 is recommended.

    292H Series
    This cam is for the serious street/strip type car. An aftermarket torque converter should be used as well as headers, intake and increased compression. The 292H has a radical, rough idle.

    305H Series
    The 305H should really be considered for Pro-Street type cars where actual streetability is not a major concern. The design of this cam also makes it ideal for all bracket racing engines. Major engine modifications are needed as well as transmission and driveline improvements. The 305H works best in large cubic inch engines and has a radical idle. This is the only hydraulic cam in the series that does not have an advance made into it and will need to be degreed in.

    Camshaft & Lifter Kits are indicated by a CL in their part number and include Camshaft, Lifters, Assembly Lube, Decals, and Instructions.

    Complete Kits are indicated by a K in their part number and include Camshaft, Lifters, Timing Chain & Gears, Valve Springs, Retainers, Locks, Assembly Lube, Decals, and Instructions.

    Small Kits are indicated by a SK in their part number and include Camshaft, Lifters, Timing Chain Set, Assembly Lube, Decals, and Instructions.

  • COMP Cams CL51-233-4

    Exhaust Valve Lift (in.)
    Intake Valve Lift (in.)
    RPM Range
    Exh. Duration @ .050 in. (Deg)
    Int. Duration @ .050 in. (Deg)
    Exh. Duration Advertised (Deg)
    Int. Duration Advertised (Deg)
    Lifter Type
    Hydraulic Flat Tappet
    Engine Make/Size
    Pontiac 265-455
    Gaskets Included
    Advertised Duration
    270 int./270 exh.
    Advertised Exhaust Duration
    Advertised Intake Duration
    Assembly Lubricant Included
    Basic Operating RPM Range
    Cam Style
    Hydraulic flat tappet
    Computer-Controlled Compatible
    Duration at 050 inch Lift
    224 int./224 exh.
    Exhaust Duration at 050 inch Lift
    Exhaust Valve Lift with Factory Rocker Arm Ratio (
    Grind Number
    Intake Duration at 050 inch Lift
    Intake Valve Lift with Factory Rocker Arm Ratio (i
    Lifter Style
    Hydraulic flat tappet
    Lifters Included
    Locks Included
    Pushrods Included
    Sold as a kit
    Retainers Included
    Rocker Arms Included
    Timing Chain and Gears Included
    Valve Lift with Factory Rocker Arm Ratio
    0.476 int./0.476 exh.
    Valve Springs Included
    Valve Springs Required
    Valve Stem Seals Included
    Lobe Separation (Deg)
    Manufacturer's Part Number:
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