Editing Camshaft install tips and tricks

==Disclaimer== 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 "frag" a flat-tappet camshaft and lifters== ===Cleaning=== '''1. Failure to remove all rust-preventative from cam and lifters with solvent once you get them home.''' This advice does not include removing coatings applied at the factory such as phosphates. It is only suggesting to remove rust-preventative grease that may or may not have been applied to the cam/lifters to prevent rust in storage. This grease will not have the extreme pressure characteristics that Molybdenum Disulphide has and should be removed so that MD can be applied properly. MD is the black, tar-like extreme-pressure grease that is recommended by some camshaft manufacturers to be applied to the lifter crowns/cam lobes for initial flat tappet camshaft break-in. '''2. Failure to wash the cam and lifters with hot soapy water to remove the remainder of rust-preventative not removed with solvent.''' Caution: wash only the crown of the lifters: the very bottom of the lifter where it contacts the camshaft lobe. Do not allow water to get into the interior of the lifter body. Be very careful here if the lifter has an oiling hole that has been EDM'd into the crown to provide oil from the interior of the lifter body to the camshaft lobe. Before applying molybdenum disulphide, dry the cam and lifter crowns thoroughly with hot air from a hot air gun or hair dryer, to remove all traces of moisture. Do not use any abrasive materials such as Scotch-Brite pads or sandpaper of any kind to accomplish these solvent and soap cleaning operations. Use only soft, clean rags. The camshaft is cleaned so that rust-preventative oils and greases can be completely removed. If left on the camshaft, such substances might hinder the penetration of an extreme pressure lubricant such as molybdenum disulphide. ===Installation and Pre-lube=== '''3. Actual installation of the camshaft into the block.''' On a complete engine assembly, it is often helpful to install the camshaft BEFORE the crankshaft; in many cases the cam would be the first major part to be installed by the assembler after "final cleaning" of the block. (The cam bearings and block plugs are likely to be installed by the machine shop.) If this is the case, it is very helpful to--if possible--set the block on the floor bellhousing-side DOWN, so the block is vertical. The camshaft then can be lowered into the block straight down, and there's minimal effort needed to assure that the cam lobes and cam journals DO NOT nick the bearings. If the cam MUST be installed horizontally, it is almost mandatory to use a "handle" on the front of the cam, and to take particular care that the cam doesn't bang into, or scrape across the bearings. Whether vertical or horizontal, if the crankshaft isn't in the way, it's easy to guide the cam through the bearings with one hand while supporting the front end of the cam with the other. '''4. Failure to properly massage an extreme pressure lubricant such as molybdenum disulphide into the pores of the metal on all lobes and lifter faces.''' Molybdenum disulphide will actually bond with the metal and give maximum protection to the lifter crown/lobe. Use the 'moly' lube on the distributor gear, cam lobes and the lifter foot that contacts the lobe only- '''not''' the bearing journals, and '''not''' the sides of the lifters. Engine oil or ATF can be used on the lifter bores or lifter sides, and the pushrod cups. '''5. Failure to verify "lifter spin" on flat-tappet lifters.''' With the camshaft and lifters installed, but before the timing chain is attached or the pushrods are installed, mark each lifter and lifter bore with a "Sharpie" or other marker. A simple stripe on the lifter bore aligned with a dot on the visible part of the top of the lifter is fine. Rotate the camshaft several revolutions, and assure that the lifters spin in the bores, as noted by the increasing misalignment of the dot on the lifter relative to the stripe on the lifter bore. The lifters may not all spin the same amount--some will spin more than others--but they must all show some rotational movement as the cam spins. The only exception to this that I'm aware of is Buick "Nailhead" V-8s, which (at least in OEM form) have no crown on the lifter foot, no taper on the cam lobe, and no offset between lifter bore and cam lobe. The Nailhead lifters are NOT intended to spin. '''6. Failure to use an extreme pressure lubricant additive in the engine oil for camshaft break-in.''' There are many different products for facilitating valid cam 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 Zinc dialkyldithiophosphates (ZDDP). Most ZDDP additives 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. ====ZDDP resources==== *[http://www.zddplus.com/ ZDDPlus.com] (includes various tech briefs) *[http://www.sfrcorp.com/product/sfr-100-petroleum-oil-fortifier/ SFR 100 Oil Fortifier] *[http://www.zddplus.com/ZDDPlus%20MSDS.pdf ZDDPlus MSDS] *[http://www.zddpforum.com/forum/ ZDDP forum] ====Valve springs==== '''7. 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 (if those springs will accept the amount of valve lift and the retainers will clear the valve seals/valve guides) 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 expensive, these are available from [http://crower.com/ 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 accommodate the longer pushrod cup to pivot dimension and maybe alter the slots in your guide plates as well. '''8. Failure to check for valve spring coil bind at max lift.''' If you cannot tell by eye, verify by inserting a .010" feeler gauge between the coils. A .010" between five coils would give a total of .050" safety margin before stacking the spring solid. If you cannot pass the feeler gauge between the coils, the spring is either coil bound or dangerously close to this condition, and you have probably over shimmed the spring (the fitted dimension is too short). '''9. Failure to check for retainer to valve guide/seal clearance.''' 1/16"-1/8" clearance at full valve lift is considered sufficient. This is the limiting lift factor with the stock L31 Vortec heads. Most uninformed people will say they can run a 0.500" lift cam with them stock. That leaves ZERO clearance between the retainer and the seal. Not good. GM says the limit is about 0.420" with the stock pieces. GM engineers say 0.420" lift allows 0.030" retainer-to-seal clearance. ===Checking clearances=== '''10. Failure to check for binding at the rocker/stud interface with stamped steel rockers.''' Long slot rockers are made specifically to cure this problem. Quality roller rockers with a needle bearing trunnion are as good as it gets with a stud-mounted rocker. '''11. Failure to check for piston/valve clearance''' 0.080" on the intake and 0.100" on the exhaust is considered by many to be the minimum clearance acceptable. You will probably find the closest near-miss at the exhaust valve on overlap, when the piston is chasing the exhaust valve back onto its seat. ===Engine RPM for break in=== '''10. Failure to run the motor at high rpm (2500 or higher, alternating 500/1000 rpm up and/or down to allow the crank to throw oil in different places at different revs) for a minimum of 20 minutes. 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 source of camshaft lubrication is oil thrown off of the crankshaft at speed, drain back from the oil rings and oil vapors circulating in the crankcase. At idle, the crank isn't spinning fast enough to provide sufficient oil splash to the camshaft/lifters for proper break-in protection. '''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 way to provide a flat tappet cam and lifters with additional lubrication is to groove the lifter bores. One tool for doing this operation is the [http://www.summitracing.com/parts/CCA-5003/ Comp Cams p/n 5003] lifter bore grooving tool sold by Summit. Solid lifter flat tappet lifters are available with a small machined hole in the lifter foot that feeds pressurized oil to the interface between the cam and lifter. '''12. Failure to initially adjust the valves properly.''' Using the "spin the pushrod until it feels tight" method may result in valves too tight. Holding the rocker arm tip down against the valve stem tip with one hand, jiggle the pushrod up and down with your thumb/forefinger of your other hand until all play is removed, then turn the rocker nut the number of times specified by the lifter manufacturer to set the preload. (Another good reason to buy lifters from someone you can talk with about them on the phone instead of buying them in a white cardboard box with no name on it). Builders who have done hundreds of engine builds may have the "feel" to do the "twist" method, but those who are doing their first few builds lack the experience to do this and will have better results with the "jiggle the pushrod up and down" method. '''13. Failure to inspect the distributor drive gear for wear.''' Too much wear can allow the cam to walk in its cam bore and contact an adjacent lifter. The builder is also responsible for using a distributor gear that is compatible with the camshaft gear material. Coordinate this with the cam grinder before you ever begin assembling the motor. Hardly anything will make you feel more stupid than finding one or the other of the gears eaten up, necessitating an engine tear-down to clean out all the shrapnel. '''14. Failure to have everything ready for the motor to fire on the first few turns.''' Fully charged battery, good starter, known-good carburetor with full fuel bowl, source of fuel to the carburetor to allow minimum 20 minutes of uninterrupted running. Ignition timing set. Warning: no grinding on the starter! '''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 certain that pressure is registering. Priming will aid lubing the valve train at initial start up. 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 of a Chevrolet-designed V-8 unless you use either the distributor or the tool to block off the oil galley under where the distributor bolts down. Here is an example of a tool for use with a Chevrolet engine: [http://paceperformance.com/index.asp?PageAction=VIEWPROD&ProdID=25140 Proform oil pump prime tool].That sort of tool is not needed on, for example, Oldsmobile- or Pontiac-designed V-8s. Priming is not intended to initially lubricate the internal engine components. Every moving part should have received lubrication when the engine was assembled. Priming the oil system is a process to remove air from the pressurized portions of the oiling system, i.e. the oil pump, the oil filter, and some of the oil galleries (the oil galleries will begin to drain the oil as soon as the priming stops but the oil pump and filter are likely to remain full.) Priming is "done" when you see oil pressure on the gauge, plus about ten or fifteen seconds additional. Often the crank will also be rotated two revolutions while the priming is being done to allow all the lifters to see pressurized oil from the lifter oil gallery. Engines that use a submerged oil pump--Chevrolet big- and small- blocks, Oldsmobile V-8, Pontiac V-8, etc., priming is usually done in ''less than one minute''. Engines with non-submerged oil pumps (Buick V-8, for example) may take considerably longer due to the difficulty in pulling oil through the long pickup tube to the remote-mounted pump. However, once you show pressure on the gauge, another ten or fifteen seconds is entirely sufficient. There is NO need to prime until the oil squirts over the fender; and in fact some engines won't show oil at the rocker arms until it's running. Engines with an oil pump that is not driven by the distributor like the GM LS-series, Vega 2.3L, some later Buick V-6, etc. can be primed by injecting pressurized oil into the oil pressure gauge port. A hand-pumped garden-sprayer-type pressure vessel will work if you can adapt the end of the hose to appropriately-threaded fittings to suit the port in the block. Put the engine oil into the pressure vessel, pump the handle, squirt all the oil into the oil sender port. The pressure used doesn't really matter--if the oil squeezes into the engine at two or five psi...that's just fine. '''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. If you purchase a used flat tappet cam from a swap meet or yard sale, plan on using it for a doorstop. ==Tools== *[http://www.summitracing.com/parts/CCA-5003/ Lifter bore grooving tool] allows pressurized oil from the lifter galley to be squirted directly onto the cam lobe/lifter interface ==Lubrication== That pencil-point of contact between the camshaft lobe and lifter crown is under somewhere between 250,000 and 300,000 pounds per square inch of pressure, so it should come as no surprise that extreme pressure lubrication is required, especially at break in where the contact point between lobe and lifter is irregular. The break in grease applied to the bottoms of the lifters and to the cam lobes is all the lubrication there is during the initial 5 to 10 seconds of operation, until motor oil reaches the interface. ===Comp Cams's position on break-in additive and nitriding=== <blockquote> ''"Due to federal legislation, motor oils no longer contain certain anti-scuffing agents that played a critical role in flat tappet camshaft break in. While incorrect valve spring pressure and not following proper break-in procedure are often the culprits, the changes in oil formulation have brought about a need for additional steps to be added to the break-in process.'' <br><br> ''COMP Cams has two ways to ensure proper break-in of flat tappet cams. COMP Cams Engine Break-In Additive (part #159) ensures that the camshaft will have the lubricants that it needs to seat the camshaft journals and lobe/lifter surfaces. This lubricant is poured into the engine crankcase after the camshaft and lifters have been coated with the initial break-in lubricant (molybdenum disulphide) supplied with the camshaft.'' <br><br> ''Another option for increasing flat tappet cam longevity is nitriding. Recently COMP Cams invested in a nitriding machine, the first of its kind owned by a major U.S. aftermarket camshaft manufacturer. Nitriding actually hardens the surface of the camshaft and tappet face by injecting nitrogen “needles” into the metal. The result is an ultra-hard surface on the face of the camshaft lobes and lifter face, which greatly improves the performance and break-in process for flat tappet cams. This process is an additional charge for COMP Cams camshafts, but for many extreme duty applications, it virtually ensures proper break-in and increased durability."'' </blockquote> ===Racer Brown's position on oil level during break-in=== Racer Brown is a world-renowned camshaft manufacturer/engineer who ground the hot cams for Chrysler Corporation during the horsepower wars of the 60's. <blockquote> ''"Overfill the crankcase by at least 4 or 5 quarts of oil so that the oil level comes to within an inch of the top of the oil pan. Install a set of fairly hot spark plugs with a gap of 0.050" to 0.060" to prevent oil-fouling of the plugs, which is otherwise inevitable under no-load conditions with all the extra oil aboard. During this operation, we want near-maximum oil flow, together with a maximum of oil vapors and liquid oil thrashing about in the crankcase so that the cam lobe and lifter interface lubrication is considerably better than marginal."'' </blockquote> ===Lubricants=== *[http://en.wikipedia.org/wiki/Molybdenum_disulfide Molybdenum disulfide] *[http://en.wikipedia.org/wiki/Zinc_dithiophosphate Zinc dithiophosphate] *[http://www.compperformancegroupstores.com/store/merchant.mvc?Screen=PROD&Store_Code=CC&Product_Code=159&Category_Code= Comp Cams Engine Break-In Oil Additive] *[http://www.hotrodders.com/forum/assembley-lube-good-anything-174183.html#post1239633 Hotrodders forum thread on cam and assembly lubricants] ==Resources== *[http://www.carcraft.com/techarticles/ccrp_1108_camshaft_break_in_guide/viewall.html Camshaft Break-In Guide - How To Break In That Flat-Tappet Cam] Car Craft, August, 2011 *[http://www.sirgalahad.org/tyler/misc/camdesign.txt Cam design] ==Crankshaft Coalition Wiki References== *[[Valve train points to check]] *[http://www.crankshaftcoalition.com/wiki/Category:Adjust_valves Adjust valves] [[Category:Engine]] [[Category:Camshaft]] [[Category:Adjust valves]] [[Category:Good articles]]

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