Camshaft install tips and tricks

4. Failure to use an extreme pressure lubricant additive in the engine oil for camshaft break-in. Each cam grinder has his own specific product to facilitate valid cam break-in. The aftermarket has also come to our rescue with many different formulations of ZDDP. Here are a couple of offerings for your approval....Most of them will recommend a specific quantity in the oil for break-in and then half that amount for each subsequent oil change. Yes, it is possible to get too much ZDDP in the oil and generate spalling of the cam lobes, so do your research or use roller lifters where this stuff is not required.  

4. Failure to use an extreme pressure lubricant additive in the engine oil for camshaft break-in. Each cam grinder has his own specific product to facilitate valid cam break-in. The aftermarket has also come to our rescue with many different formulations of ZDDP. Here are a couple of offerings for your approval....Most of them will recommend a specific quantity in the oil for break-in and then half that amount for each subsequent oil change. Yes, it is possible to get too much ZDDP in the oil and generate spalling of the cam lobes, so do your research or use roller lifters where this stuff is not required.  

5. Failure to use the proper valve springs for cam break-in. You can't use the 300 lb over-the-nose springs that you'll eventually use in the motor and expect the cam to live at break-in. Assemble the heads with stock or weak single springs to break in the cam, then use one of the many tools available to change the springs with the heads on the motor. Those without shop air to hold the valves up through this operation can feed some clothesline cord through the spark plug hole and then bring the piston up to smash the rope and hold the valves up. Alternately, assemble the heads with the springs you will run and use reduced-ratio break-in rockers, then change out the rockers after break-in. Although pretty "spendy", these are available from Crower in different ratios for different motors. A popular ratio for a small block Chevy would be a 1.3:1 rocker. In other words, let's say the lift at the cam is 0.350" and the theoretical lift at the valve with 1.5:1 rockers is 0.525". Using the 1.3:1 rockers would result in lift at the valve of only 0.455", thus reducing stress at the camshaft/lifter interface during the crucial break-in period. Of course, you would have to elongate the pushrod holes to accomodate the shorter pushrod cup to pivot dimension and maybe alter the slots in your guide plates as well.  

5. Failure to use the proper valve springs for cam break-in. You can't use the 300 lb over-the-nose springs that you'll eventually use in the motor and expect the cam to live at break-in. Assemble the heads with stock or weak single springs to break in the cam, then use one of the many tools available to change the springs with the heads on the motor. Those without shop air to hold the valves up through this operation can feed some clothesline cord through the spark plug hole and then bring the piston up to smash the rope and hold the valves up. Alternately, assemble the heads with the springs you will run and use reduced-ratio break-in rockers, then change out the rockers after break-in. Although pretty "spendy", these are available from Crower in different ratios for different motors. A popular ratio for a small block Chevy would be a 1.3:1 rocker. In other words, let's say the lift at the cam is 0.350" and the theoretical lift at the valve with 1.5:1 rockers is 0.525". Using the 1.3:1 rockers would result in lift at the valve of only 0.455", thus reducing stress at the camshaft/lifter interface during the crucial break-in period. Of course, you would have to elongate the pushrod holes to accomodate the shorter pushrod cup to pivot dimension and maybe alter the slots in your guide plates as well.  

11. Failure to clearance lifters in their bores so that they spin freely. Lifter clearance should be 0.0012" to 0.002", with 0.0015" (one and one/half thousandths) considered close to ideal. Too loose is as bad as too tight. One more way to "bulletproof" a flat tappet installation is to groove the lifter bores for oiling the cam lobes. See the first tool in this link....

11. Failure to clearance lifters in their bores so that they spin freely. Lifter clearance should be 0.0012" to 0.002", with 0.0015" (one and one/half thousandths) considered close to ideal. Too loose is as bad as too tight. One more way to "bulletproof" a flat tappet installation is to groove the lifter bores for oiling the cam lobes. See the first tool in this link....

15. Failure to prime the oiling system prior to firing the motor. Prime until you get oil out of the top of each and every pushrod. Observe the oil pressure gauge to be sure pressure is registering. Priming will aid lubing the valvetrain at initial startup. It's the last area of the motor to get lubed on dry start. You can make a tool by disassembling an old distributor and removing the gear or just grinding off the gear teeth so that the teeth don't engage the cam teeth. Or, you can spring for 20 bucks and get a very nice priming tool that will be a nice addition to your tool chest. In either case, you will NOT get oil to the passenger side rockers unless you use either the distributor or the tool to block off the oil galley under where the distributor bolts down.

15. Failure to prime the oiling system prior to firing the motor. Prime until you get oil out of the top of each and every pushrod. Observe the oil pressure gauge to be sure pressure is registering. Priming will aid lubing the valvetrain at initial startup. It's the last area of the motor to get lubed on dry start. You can make a tool by disassembling an old distributor and removing the gear or just grinding off the gear teeth so that the teeth don't engage the cam teeth. Or, you can spring for 20 bucks and get a very nice priming tool that will be a nice addition to your tool chest. In either case, you will NOT get oil to the passenger side rockers unless you use either the distributor or the tool to block off the oil galley under where the distributor bolts down.

16. Failure to use new lifters on a used cam. Used lifters should only be used on the very same cam, in the very same block and in the very same positions they were removed from. Chances that the lifter bores will be machined on the very same angles on a different block as the block the lifters came out of are about equal to you hitting the lottery.

16. Failure to use new lifters on a used cam. Used lifters should only be used on the very same cam, in the very same block and in the very same positions they were removed from. Chances that the lifter bores will be machined on the very same angles on a different block as the block the lifters came out of are about equal to you hitting the lottery.