Camshaft install tips and tricks
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==Lubrication== | ==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. | 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's position on oil level during break-in=== | ||
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''"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."'' | ''"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> | </blockquote> | ||
| + | |||
| + | ===Lubrication requirements after break in=== | ||
| + | For the same reasons break in oil or break in oil additives are used to break in the cam and lifters, '''''after''''' cam/lifter break in, only oils formulated for flat tappet equipped performance engines should be used. Also acceptable is using additives like ZDDPlus, etc. (in the correct quantity- less than for initial break in) added to over the counter motor oil. | ||
===Lubricants=== | ===Lubricants=== | ||
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*[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.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] | *[http://www.hotrodders.com/forum/assembley-lube-good-anything-174183.html#post1239633 Hotrodders forum thread on cam and assembly lubricants] | ||
| − | + | *[http://www.enginebuildermag.com/Article/106244/breakinin_is_hard_to_do.aspx How break-in oils are different than the rest and why you need them] Engine Builders Magazine | |
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==Adjusting the cam timing or "phasing"== | ==Adjusting the cam timing or "phasing"== | ||
Cam phasing is the relationship of the camshaft position to the crankshaft position in reference to TDC. A change of 2 degrees at the cam gear equals 4 degrees at the crank. | Cam phasing is the relationship of the camshaft position to the crankshaft position in reference to TDC. A change of 2 degrees at the cam gear equals 4 degrees at the crank. | ||
| − | {{ | + | {{Note1}}When advancing/retarding the cam, be sure to check valve to piston clearance. Each degree of change effects valve clearance approximately 0.010". Example: If you advance the camshaft 4 degrees, you will '''lose''' about 0.040" clearance between the intake valve and piston, and you will ''gain'' about 0.040" clearance between the exhaust valve and piston. It will be the opposite if the camshaft is retarded. |
The cam timing, or phasing, can be changed at the time of installation by using a multi-keyway timing set, or an adjustable cam gear like [http://www.cloyes.com/HighPerformance/Products/HexAJustTrueRollerSets/tabid/383/language/en-US/Default.aspx Cloyes Hex-A-Just]. | The cam timing, or phasing, can be changed at the time of installation by using a multi-keyway timing set, or an adjustable cam gear like [http://www.cloyes.com/HighPerformance/Products/HexAJustTrueRollerSets/tabid/383/language/en-US/Default.aspx Cloyes Hex-A-Just]. | ||
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*Increases piston to intake valve clearance | *Increases piston to intake valve clearance | ||
*Decreases piston to exhaust valve clearance | *Decreases piston to exhaust valve clearance | ||
| + | ;Also see [http://www.crankshaftcoalition.com/wiki/How_to_choose_a_camshaft#Phasing_the_camshaft Phasing the camshaft] | ||
==Effects of changing lobe separation angle== | ==Effects of changing lobe separation angle== | ||
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*Overlap increases | *Overlap increases | ||
*Natural EGR effect increases | *Natural EGR effect increases | ||
| − | *Decreases piston-to-valve clearance | + | *Decreases piston-to-valve clearance |
| + | |||
| + | ==Roller cams are '''not''' immune== | ||
| + | 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 however do not use the heavy moly cam break in lube on a roller cam or lifter- it will cause much more problems than it will cure. Instead, follow the manufacturer's instructions. 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. | ||
| + | |||
| + | {| | ||
| + | |[[File:Bad roller lobe.jpg|thumb|center|460px|Bad roller cam lobe caused by insufficient lubrication and/or valve train failure, possibly due to clearance problems]] | ||
| + | |[[File:Bad lifter rollers.jpg|thumb|center|500px|Heavily chipped/pitted/galled lifter roller]] | ||
| + | |} | ||
==Resources== | ==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.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 | ||
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*[http://www.sirgalahad.org/tyler/misc/camdesign.txt Cam design] | *[http://www.sirgalahad.org/tyler/misc/camdesign.txt Cam design] | ||
;Crankshaft Coalition Wiki articles | ;Crankshaft Coalition Wiki articles | ||
| + | *[[How to choose a camshaft]] | ||
| + | *[[Cam and compression ratio compatibility]] | ||
| + | *[[Lifters]] | ||
*[[Adjusting hydraulic lifters]] | *[[Adjusting hydraulic lifters]] | ||
| + | *[[Adjusting solid lifters]] | ||
*[[How to prep and start a rebuilt engine]] | *[[How to prep and start a rebuilt engine]] | ||
*[[Valve train points to check]] | *[[Valve train points to check]] | ||
| + | *[[Valve train geometry]] | ||
| + | *[[Pushrod length checking tool, homemade]] | ||
| + | *[[Valve spring tech]] | ||
*[http://www.crankshaftcoalition.com/wiki/Category:Adjust_valves Adjust valves] | *[http://www.crankshaftcoalition.com/wiki/Category:Adjust_valves Adjust valves] | ||
| + | *[[Camshaft tech by Dimitri Elgin]] | ||
;Hotrodders forum threads | ;Hotrodders forum threads | ||
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