Increase Your Horsepower By Installing A Cam In Your Muscle Car

The first step in installing a cam requires removing and labeling anything in front of the timing-chain cover and on top of the intake manifold. Once the coolant is drained and all the accessories are out of the way, remove the intake-manifold bolts. After removing the intake manifold, scrape the front and rear block rails clean of gasket material, silicone, oil, or any other substance. Line the lifter valley with paper towels to capture any debris.

The next step to installing a cam, is remove the valve covers to access the rockers, pushrods, and lifters. Keep the rockers and pushrods in order. While you remove the rocker nuts, the engine may have to be turned over a few times in order to take valvespring pressure away from certain rocker-to-valve stem contact points.

Installing a cam in an in-car installation, the timing cover is one of the most difficult parts believe-it-or-not! The oil pan must be lowered enough to remove the timing cover while also clearing the crankshafts snout. With the cover off the engine, remove the three upper timing-chain bolts, along with the lower timing gear if a new timing chain is to be installed. When installing a cam, a fresh chain provides cheap insurance; a "seasoned" chain has a tendency to stretch and can alter timing by as much as 2 degrees. A high-performance double roller chain can prevent stretch and is a lot less likely to break or skip a gear tooth that would otherwise destroy the entire valvetrain. After changing the upper and lower timing gears, remove the old camshaft.

You can work the cam out of the engine block by twisting it slowly and carefully, taking every precaution not to scratch or gall the cam-bearings in the process. Clean and lube the new cam before installation. Move it as far back as the plug at the rear of the block will allow, and fasten the upper timing gear. Once the camshaft's timing-gear bolts are secure, it's time to set the valve timing. Begin by making sure that the upper timing gear has the manufacturer's pre-marked timing dot at the 6 o'clock position. Then, in a linear sequence with the upper timing-gear dot, rotate the crankshaft until the same dot or equivalent marking on the lower timing gear is at 12 o'clock. This sets the engine's rotating assembly at Top Dead Center and its timing at 0 degrees of rotational advance.

We use the term "equivalent marking" because some high-performance chains offer different degrees of advance or retard for specific applications. These markings are visible on the crankshaft gear and tell the engine builder at what degree of rotation the crankshaft will be set at when the camshaft is installed. Many high-performance cams have timing advance pre-ground into the camshaft and require the installer to set the cam and crank gears in sequence with one another, so check the manufacturer's recommendation. With the camshaft in place, the upper timing gear should have its timing dot in the 6 o'clock position; the lower timing gear should show its zero-degree marking in the 12 o'clock position. Checking this will ensure proper valvetrain movement and allow the engine to respond the way the camshaft intends it to. There's more to installing a cam than you thought, right?

Once the timing chain is in place, take the utmost care in positioning the lower portion of the timing cover over the oil pan to make sure oil does not leak from the front of the engine. Thorough cleaning is critical before the silicone is applied between the oil pan and timing-cover seal contact points. Once a seal is created, the oil pan can be tightened back into place. If the gasket is undamaged, it can be cleaned before spreading a thin layer of silicone between the pan and the block.

Lube the new lifters liberally and drop them back into their bores. Then slide the pushrods through the cylinder-head holes and install the rocker arms. Put the pushrods against the rocker cups. At this point, it's also a good idea to check the pushrod length. Mark one of the valve tips with a black Sharpie before the rocker is installed and spin the engine through several revolutions. Remove the rocker arm and check out the valve tip. If the rub point is in the middle of the valve tip, the pushrod is the correct length. If it occurs closer to the rocker stud, the pushrod is too short, and visa-versa if it is too long. Now, you can adjust the valves.

Turn the engine over several times via the starter or by hand until the intake lifter of the number one cylinder begins to rise. When it reaches full lift, tighten the exhaust rocker until the lifter plunger just begins to move. From there, tighten the rocker nut 1/2-turn and lock it in place with the jam nut. The idea is to preload the lifter plunger but not bottom it out. Repeat the process across the engine, lashing the opposite rocker (of the same cylinder) of the one at full lift. When all 16 are complete, fasten the valve covers and install the intake manifold.

The intake manifold runners must be sealed tight after installing a cam, because a bad seal will suck oil into the combustion chamber, causing sluggish throttle response and poor fuel mileage. Once the new intake gaskets are installed, build up the oil valley rails by spreading a liberal bead of silicone across them. Set the intake down gently and use the bolts to pull it into place. Following the gasket manufacturer's torque sequence will ensure a proper manifold seal.

Now, as one of the final steps to installing a cam, you're ready to put the distributor back in the engine. First and foremost, the number one piston must be at Top Dead Center. Check this by removing the spark plug and placing a finger over the hole. As compression stroke finishes pushing air out of the hole, the piston is at Top Dead Center and properly set. Lower the distributor into the engine while making sure the rotor is pointing directly toward the number one spark plug lead. The trick is getting the rotor to face the proper direction while mating the oil-pump drive with the distributor shaft.

If necessary, use a long flat-head screwdriver to rotate the pump drive. A few tries and the distributor should mate with the oil-pump shaft and have the rotor facing close to the number 1 plug lead. With a little timing advance, the engine should easily fire and allow you to set the total timing. It's also a good idea to change the oil and filter after the camshaft is broken in.

A flat-tappet cam relies primarily on oil splash to lubricate its lobes, so it's important to raise engine rpm quickly and vary it between 2200 and 3500 rpm, depending on the manufacturer's recommendation. This allows the concave surface of each lifter to develop the minute wear pattern necessary to seat the lifter against its camshaft lobe. After about 20 minutes of break-in, we were ready to cook.

Here's some things you’ll need for installing a cam: New camshaft and lifters of course, distributor gasket, water pump gasket, valve cover gaskets, timing cover gasket, intake manifold gaskets, a pry bar, harmonic balancer puller, 1/4 inch standard sockets, 3/8 inch standard sockets, 1/2 inch standard sockets, flat-head screwdrivers, phillips screwdrivers, water pump pliers, an adjustable wrench, 1/4 inch ratchet, 3/8 inch ratchet, 1/2 inch ratchet, a torque wrench, a telescoping magnet, some carb cleaner, rags, oil, a new oil filter, antifreeze, and some oil Treatment.

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