• P177970 Image Large
    Hydraulic-roller cams have become the new darling of the performance world. The least expensive route is to build an ’87-or-later small-block that came with a hydraulic-roller cam so you can employ factory hydraulic-roller tappets. This is the GM Performance Parts Hot cam and accessories for a hydraulic-roller-cam block.
    Hydraulic-roller cams have become the new darling of the performance world. The least expe
  • P177971 Image Large
    Flat-tappet cams (below) are less expensive than hydraulic-roller cams (top), but a roller offers significant power potential, especially for mild street engines.
    Flat-tappet cams (below) are less expensive than hydraulic-roller cams (top), but a roller
  • P177972 Image Large
    Rocker arms are an easy way to add valve lift to an existing camshaft. Shown from the left are stock stamped rockers from Crane, Crane Gold Race aluminum rollers, and Comp Cams Pro Magnum roller rockers.
    Rocker arms are an easy way to add valve lift to an existing camshaft. Shown from the left
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    Rocker-arm ratio is based on the distance between the pushrod cup and the centerline of the rocker. To increase the rocker ratio, the pushrod cup moves closer to the rocker centerline. The rocker on the left is a 1.52:1 ratio, and the rocker on the right is a 1.6.
    Rocker-arm ratio is based on the distance between the pushrod cup and the centerline of
  • P177974 Image Large
    More aggressive camshafts, especially hydraulic-roller cams, require stronger valvesprings. One way to accommodate more lift is with a larger- diameter spring that increases the spring pressure. Stock small-block springs are generally 1.250-inch outside diameter (od). Larger 1.440-inch springs are the next step up.
    More aggressive camshafts, especially hydraulic-roller cams, require stronger valvesprings
  • P177975 Image Large
    Crane makes an excellent H-11 Tool Steel spring that will fit the confines of the stock small-block spring pad while offering a 406-lb/in rate that can handle up to 0.600-inch valve lift. This spring requires a guide with an inside diameter no larger than 0.760 inch.
    Crane makes an excellent H-11 Tool Steel spring that will fit the confines of the stock sm
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    ARP makes an excellent poly lock called the Perma-Lock, which offers a 12-point hex that prevents the wrench from slipping down over the lock during lash adjustment. This is a very useful feature for adjusting valves.
    ARP makes an excellent poly lock called the Perma-Lock, which offers a 12-point hex that p
  • P177981 Image Large
    Adjusting valves is easy if you remember this simple procedure. When the exhaust valve just starts to open, adjust the intake. Then bump the engine over and when the intake is almost closed, adjust the exhaust. The shorthand is exhaust opening (EO), intake closing (IC)—or EO-IC.
    Adjusting valves is easy if you remember this simple procedure. When the exhaust valve j
  • P177982 Image Large
    GM Performance Parts makes an interesting 1.330-inch-od spring for ’96 LT4 engines. It employs an ovate wire to increase valve-lift potential (kit, PN 12495494; spring retainer, PN 10212808). This spring can handle up to 0.510-inch valve lift.
    GM Performance Parts makes an interesting 1.330-inch-od spring for ’96 LT4 engines. I

If cylinder heads are the heart of an engine, then the camshaft and valvetrain have to be the brains of the operation. Timing the opening, closing, lift, and duration of each valve event is central to increasing power and torque. While something this complex might seem expensive, the price of camshaft admission is surprisingly affordable.

Rather than deal specifically with camshafts in this particular story, we’ll focus instead on several options that you can take concerning rocker ratios, poly locks for the street to maintain that valve lash, and how to save a little money on your next engine buildup using a hydraulic-roller camshaft. So climb on board as we take a high-tech ride on the valvetrain.

SOURCE
Automotive Racing Products (ARP)
531 Spectrum Circle
Oxnard
CA  93030
805-278-7223 		GM Performance Products
Contact your nearest dealer
COMP Cams Scoggin-Dickey Parts Center
Lubbock
TX
N/A
www.sdparts.com
Crane Cams
530 Fentress Blvd.
Daytona Beach
FL  32114
3-86/-252-1151
N/A
www.cranecams.com
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