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Car Craft - How To Degree A Cam In An LS Engine - Step By Step

Discussion in 'COMP Cams Technical Reference Articles' started by jjamros, Feb 14, 2011.

  1. jjamros

    jjamros Guest

    Horsepower has never been easier to make, and the motor leading the charge is the new LS engine. What we've learned is that just the simple addition of a more aggressive camshaft can easily add 50 to 100 hp to an otherwise stock LS engine. This applies to virtually all the LS series of engines. And if you're going to the effort of bolting in a camshaft, you might as well degree it to ensure it will be timed properly. If you've never degreed a camshaft, now is a great time to learn. And if you've been through it a few times before, much of this will be very familiar, even if we're doing it on a new engine. Let's get started.

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    There are some interesting details about cam timing that may come in handy when you begin the engine-building process. The lobe-separation angle (sometimes called the lobe-center angle) is the distance in cam degrees between the intake and exhaust lobe centerlines. Decreasing the angle (106 versus 114 degrees) between these lobe centerlines increases the amount of overlap. Generally, with longer-duration camshafts, a wider lobe-separation angle is needed to maintain a given amount of overlap. If duration is increased and lobe-separation angle is tightened, it drastically increases the amount of overlap. Conversely, a wide lobe-separation angle used in stock LS engines can approach 116 to 118 degrees or more, reduce the overlap, and create a very smooth idle.

    As an example, the cam we used in the degree process has a lobe-separation angle of 113 degrees, yet the intake centerline is listed as 109 degrees ATDC. If a camshaft is ground with no advance, the intake centerline and lobe-separation angle will be the same. With the Comp cam used in our story, the intake centerline is actually 4 degrees advanced in relation to TDC. Most cam manufacturers dial a certain amount of advance into cams intended for street use to improve low-speed throttle response with earlier opening and closing points. Since the camshaft is already advanced before it finds its way into the engine, degreeing the cam is important to verify the valve opening and closing points and also points out why advancing the cam further may not be a good idea.

    To read the rest of the article, pick up the March, 2011 issue of Car Craft magazine or visit the Car Craft website here.

    Source:
    March, 2011 issue of Car Craft
    By Jeff Smith
    Photography by Jeff Smith
    COMP Cams LS Engine Degree Kit
     

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    Last edited by a moderator: May 28, 2014

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