How to Break in a New Cam

Break-In Procedures

With the dummy oil-pump drive... 

   

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With the dummy oil-pump drive in the distributor hole, use an electric drill motor to spin the oil pump to create oil pressure. Remember to spin the oil pump in the correct rotation. Chevys spin clockwise while Fords spin counterclockwise.

Let's assume you've just finished bolting that killer new engine in your car. Before you hit the starter motor and shake the pavement with all that horsepower, there are a couple of crucial camshaft break-in procedures you should follow. Your first step should be to remove the distributor so you can prelube the engine. Prelubing uses an old distributor or a specialty tool to independently spin the oil pump.

We built an oil-pump primer out of an old point distributor for our small-block Chevy by removing the cam drive gear and cutting off the top of the distributor-shaft weight pivot. We then had a friend machine the top of the shaft so we could use either a 11/44- or 11/42-inch drill motor. A corded 11/42-inch drill motor has the most torque. We retained the distributor body, since it directs oil to both sides of the lifter galley. Without the distributor body, only one side is lubed. Engage the oil-pump driveshaft and spin the drill motor. It's also a good idea to rotate the engine by hand a quarter turn at a time to ensure all the lifters get oil. This process should only take about five minutes but can sometimes take longer. A big-block Chevy will take much longer to pump oil to all the rocker arms-perhaps as long as 20 minutes.

Now replace the distributor by positioning the engine at No. 1 cylinder at roughly 16 degrees before top dead center (BTDC) on the harmonic balancer. Line up the distributor rotor with the No. 1 spark-plug wire on the distributor cap and cinch the distributor down. This will ensure you have around 16 degrees of initial timing in the engine when you first hit the starter. Prime the carburetor by pouring some fuel into the primary fuel bowl through the vent tube. Work the accelerator linkage until you have fuel squirting into the manifold. Assuming you have also filled the engine with oil and the cooling system with water, you're ready to fire the engine. The reason for all this preparation is to minimize the amount of cranking necessary to start the engine. With everything set correctly, the engine will fire on the first or second revolution.

Once the engine fires, immediately bring the rpm up to between 2,000 and 3,000. All camshafts in V-8 engines are splash-lubricated from oil whipped up by the crankshaft. Spinning the engine at these higher speeds for the first 20 minutes ensures sufficient oil reaches the cam lobes. We prefer to have the full exhaust connected so we can hear the engine while it's running to listen for any misfire or engine problems. This is a good time to double-check the ignition timing. Also, make sure engine rpm never remains constant for the break-in period. Engine speed should vary between 2,000 and 3,000 the entire time. This ensures oil reaches all points on the camshaft. Do not merely set the fast idle on the choke and walk away from the engine. Also, use this break-in time to watch for leaks or other problem areas and to monitor the coolant level and temperature. We like to use tap water for this first break-in period so it can be easily drained if there is a problem

For the break-in period, any...        read full caption For the break-in period, any quality, multigrade oil is acceptable, since you are also going to be using an engine-oil supplement, such as GM's EOS or the cam-lube additives often included with the camshaft.	Make sure to add the break-in...        read full caption Make sure to add the break-in lubricant as well. This is Crane's Break-In Concentrate, but Comp Cams' additive and GM's Engine Oil Supplement are excellent alternatives.	When pressure-lubing the engine,...        read full caption When pressure-lubing the engine, remove the valve covers and watch for oil exiting the pushrods onto the rocker arms. Continue to prelube the engine until all 16 rockers have oil.
This is an assortment of engine-oil...        read full caption This is an assortment of engine-oil pump primers for small- and big-block Chevys. Our homemade tool used an old distributor with the top advance plate milled off.	If you pour carefully, you...        read full caption If you pour carefully, you can prime a Holley, Q-jet, or Edelbrock-style carburetor by filling the float bowl through the vent tube.