Camshaft install tips and tricks
(→Comp Cams's position on break-in additive and nitriding) |
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{{!}}Use this list as a guideline so that you remember to check all these things when installing a new flat tappet camshaft. This list is not gospel, and if the manufacturer of the camshaft you're using recommends procedures that differ from what is shown here, use the manufacturer's recommendations instead. | {{!}}Use this list as a guideline so that you remember to check all these things when installing a new flat tappet camshaft. This list is not gospel, and if the manufacturer of the camshaft you're using recommends procedures that differ from what is shown here, use the manufacturer's recommendations instead. | ||
| − | ==Mistakes that may | + | ==Mistakes that may cause failure of a flat-tappet camshaft and lifters == |
===Cleaning=== | ===Cleaning=== | ||
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===Engine RPM for break in=== | ===Engine RPM for break in=== | ||
| − | '''13. Failure to run the motor at 2500 rpm or higher (alternating 500/1000 rpm up and down) to allow the crank and rod big ends to throw oil onto the cam, for a minimum of | + | '''13. Failure to run the motor at 2500 rpm or higher (alternating 500/1000 rpm up and down) to allow the crank and rod big ends to throw oil onto the cam, for a minimum of 20 minutes.''' |
{{Warning}} No idling! The motor should not be run at less than 2500 rpm for a minimum of 20 minutes. If a problem develops, shut the motor down and fix it, then resume break-in. The main sources of camshaft lubrication is oil thrown off of the rods and crankshaft, drain back from the oil rings and oil blowing around inside the crankcase (this is known as "windage"). At idle, the crank isn't spinning fast enough to provide sufficient oil splash to the camshaft/lifters for proper break in protection. | {{Warning}} No idling! The motor should not be run at less than 2500 rpm for a minimum of 20 minutes. If a problem develops, shut the motor down and fix it, then resume break-in. The main sources of camshaft lubrication is oil thrown off of the rods and crankshaft, drain back from the oil rings and oil blowing around inside the crankcase (this is known as "windage"). At idle, the crank isn't spinning fast enough to provide sufficient oil splash to the camshaft/lifters for proper break in protection. | ||
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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. If you purchase a used flat tappet cam from a swap meet or yard sale, plan on using it for a doorstop. New lifters should not be used on an old cam, either. Given the reasonable cost of a new cam and lifter set (~$100 ca. 2012), vs. the cost of cleaning and repairing the damage done by a failed cam and lifters, the choice to use new parts is obvious. | 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. If you purchase a used flat tappet cam from a swap meet or yard sale, plan on using it for a doorstop. New lifters should not be used on an old cam, either. Given the reasonable cost of a new cam and lifter set (~$100 ca. 2012), vs. the cost of cleaning and repairing the damage done by a failed cam and lifters, the choice to use new parts is obvious. | ||
| + | Used lifters and a used solid lifter camshaft can be used, it is unfortunate that the cam grinders themselves have published this false wives tale for a very long time. In the order of preference, new camshaft/new lifters, used camshaft/new lifters and then used camshaft/used lifters. It is also preferable that the lifters stay matched to the lobe but if you have mixed them up or sourced them from a different, all is not lost. | ||
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| + | Several things must be accomplished to make a used camshaft/used lifter deal work. Each of the lifters will require that you properly polish the bottom of the lifter using a piece of window glass and a new sheet of 600 wet/dry sandpaper. The sandpaper will need to stay lubricated with a light solvent, WD-40 or similar is a good choice. Keep the lifters flat but understand that lifters have a slight convex to them. As you polish them in a figure 8 pattern you should see the center polishing first, if not and the polishing reveals the entire bottom, the lifter is beyond saving. Coloring the bottom of the lifter with a dark color magic marker will help you to see you progress. After polishing, clean all of the lifters thoroughly, several times is best. For the used camshaft, you want to make sure that there are no nicks or injuries to the lobe surfaces. You must also change out your valve springs to the lightest tension possible, not checking springs but something with minimal pressure. Apply Cam lube (Moly) to all surfaces of the lobes and bottoms of lifters - make sure to spend time rubbing the moly into the metal. A motor oil with a high level of ZDP should be used for the initial break-in period, removed after 30-40 minutes of run time and a second dose of the same oil along with a new filter should be used until the first oil change. Also during the initial break-in period, the oil level should be raised one to two quarts to encourage splash lubrication. In some instances a slightly hotter spark plug might be required due to oil fouling. | ||
'''19. Failure to observe the lifters and pushrods turning with the motor running.''' | '''19. Failure to observe the lifters and pushrods turning with the motor running.''' | ||
| − | If the lifter is not turning, the cam lobe is hitting on the same spot on the lifter every revolution and it won't be long until the lifter yields and then takes the lobe out with it. All lifters and all pushrods must be turning for successful engine operation. | + | If the lifter is not turning, the cam lobe is hitting on the same spot on the lifter every revolution and it won't be long until the lifter yields and then takes the lobe out with it. All lifters and all pushrods must be turning for successful engine operation. |
| − | + | ||
==Lubrication== | ==Lubrication== | ||
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</blockquote> | </blockquote> | ||
| − | George "Honker" Striegel (owner of Clay Smith Cams) said in an article on Ford inline 6 engines: Lets talk about that special treatment Comp Cams offers, for an additional $110 dollars. It's true that nitriding a cam raises the Rockwell hardness to 55-60, however they do nothing to increase the hardness of their lifters and most everyone will agree that it's the lifters that go first, then take out the lobe. In fact, the tech at Comp Cams told me that once the cam is broke in, the nitrided surface breaks down and eventually matches the hardness of the lifter. Right.... Clay Smith, Isky, Crane, and several others, experimented with nitriding several years ago. They found that nitriding offered no advantage, simply because they couldn't offer a lifter with the same hardness, at an affordable price. Yes, lifters can be made to match the hardness, but at a considerably higher price (which is probably why Comp Cams doesn't offer them). Next they discovered that a cam, or crankshaft, that had been nitrated was more prone to cracking due to stress resulting from flex and temperature fluctuations. Once the surface is damaged in any way, it cracks and eventually disintegrates, which accelerates wear at an even faster pace. And as expected, the mismatched cam and lifter hardness accelerates wear on the weaker component (lifters), which is true on all metal parts where the hardness is mismatched, such as distributor gears. On a final note, the nitrided cam carries the same warranty as a non-treated cam. If the process is as good as they say, why don’t they offer an extended warranty on the treated cams? | + | George "Honker" Striegel (owner of Clay Smith Cams) said the following in an article on Ford inline 6 engines (to be taken with a grain of salt): Lets talk about that special treatment Comp Cams offers, for an additional $110 dollars. It's true that nitriding a cam raises the Rockwell hardness to 55-60, however they do nothing to increase the hardness of their lifters and most everyone will agree that it's the lifters that go first, then take out the lobe. In fact, the tech at Comp Cams told me that once the cam is broke in, the nitrided surface breaks down and eventually matches the hardness of the lifter. Right.... Clay Smith, Isky, Crane, and several others, experimented with nitriding several years ago. They found that nitriding offered no advantage, simply because they couldn't offer a lifter with the same hardness, at an affordable price. Yes, lifters can be made to match the hardness, but at a considerably higher price (which is probably why Comp Cams doesn't offer them). Next they discovered that a cam, or crankshaft, that had been nitrated was more prone to cracking due to stress resulting from flex and temperature fluctuations. Once the surface is damaged in any way, it cracks and eventually disintegrates, which accelerates wear at an even faster pace. And as expected, the mismatched cam and lifter hardness accelerates wear on the weaker component (lifters), which is true on all metal parts where the hardness is mismatched, such as distributor gears. On a final note, the nitrided cam carries the same warranty as a non-treated cam. If the process is as good as they say, why don’t they offer an extended warranty on the treated cams? |
Cam manufacturers found the better solution was to produce cams cores with a higher nickel content, which raised the hardness to 42-46 on the Rockwell scale. By using lifters that match the hardness of the cam, which are affordable to produce, wear is greatly diminished. Today there are literally millions of consumers using high nickel cams, of which a very small percentage have had wear issues that are directly related to cam hardness. Cam failures, or lobe wear, can almost always be traced back to improper break-in, the use of cheaper motor oils, or the use of high volume oil pumps. As such cam manufacturers don't offer nitriding, simply because it isn't needed, especially if you use a good quality oil and follow the recommended break-in procedures, including a high quality break-in oil. On the other hand, if you insist on using a high volume oil pump and/or high pressure valve springs for boosted applications, then a treated cam might be better suited. Just be prepared to change out the lifters on a regular basis, which means pulling the cylinder head frequently, or spending several hundreds of dollars on chilled lifters. | Cam manufacturers found the better solution was to produce cams cores with a higher nickel content, which raised the hardness to 42-46 on the Rockwell scale. By using lifters that match the hardness of the cam, which are affordable to produce, wear is greatly diminished. Today there are literally millions of consumers using high nickel cams, of which a very small percentage have had wear issues that are directly related to cam hardness. Cam failures, or lobe wear, can almost always be traced back to improper break-in, the use of cheaper motor oils, or the use of high volume oil pumps. As such cam manufacturers don't offer nitriding, simply because it isn't needed, especially if you use a good quality oil and follow the recommended break-in procedures, including a high quality break-in oil. On the other hand, if you insist on using a high volume oil pump and/or high pressure valve springs for boosted applications, then a treated cam might be better suited. Just be prepared to change out the lifters on a regular basis, which means pulling the cylinder head frequently, or spending several hundreds of dollars on chilled lifters. | ||
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While the move has been made by the OEMs to stop using flat tappet cams and lifters in production vehicle engines (replaced by hydraulic roller cams and lifters), they are not immune to failure. | While the move has been made by the OEMs to stop using flat tappet cams and lifters in production vehicle engines (replaced by hydraulic roller cams and lifters), they are not immune to failure. | ||
| − | The same type of oil additives should be used, because it is not just the cam and lifters that require a high pressure lubricant additive; | + | The same type of oil additives should be used, because it is not just the cam and lifters that require a high pressure lubricant additive; use the heavy moly cam break in lube on a roller cam or lifter- it will cure problems. If those are not available for some unknown reason (all should be found online), use motor oil or a roller lifter-specific lube for the roller lifters and cam. |
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