Camshaft install tips and tricks

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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.
 
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.
  
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===Installation and Pre-lube===
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===Pre-lube===
 
The lifters can be dipped into a container of oil but unless the manufacturer's instructions tell you otherwise, there's no need to pump hydraulic lifters up before installing them. There are some exceptions to this. For instance Rhodes lifters DO recommend their "[I]original[/I]" lifters be pumped up prior to installing, then for them to be adjusted to 3/4 of a turn, or so the lifter cup is about 1/16" below the retainer.
 
The lifters can be dipped into a container of oil but unless the manufacturer's instructions tell you otherwise, there's no need to pump hydraulic lifters up before installing them. There are some exceptions to this. For instance Rhodes lifters DO recommend their "[I]original[/I]" lifters be pumped up prior to installing, then for them to be adjusted to 3/4 of a turn, or so the lifter cup is about 1/16" below the retainer.
  
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'''3.  Actual installation of the camshaft into the block.'''
 
  
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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.
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'''3.  Failure to properly massage an extreme pressure lubricant such as molybdenum disulphide into the pores of the metal on all lobes and lifter faces.'''
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'''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.'''
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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.
 
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.
  
  
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'''5.  Failure to verify "lifter spin" on flat-tappet lifters.'''
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'''4. Failure to use an extreme pressure lubricant additive in the engine oil for camshaft break-in.'''
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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.
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'''6. Failure to use an extreme pressure lubricant additive in the engine oil for camshaft break-in.'''
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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).
 
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).
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*[http://www.zddplus.com/ZDDPlus%20MSDS.pdf ZDDPlus MSDS]
 
*[http://www.zddplus.com/ZDDPlus%20MSDS.pdf ZDDPlus MSDS]
 
*[http://www.zddpforum.com/forum/ ZDDP forum]
 
*[http://www.zddpforum.com/forum/ ZDDP forum]
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==Installation==
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'''5.  Actual installation of the camshaft into the block.'''
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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.
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'''6. 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.
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====Valve springs====
 
====Valve springs====
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===Checking clearances===
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'''Note:''' More info on checking clearances at [[Valve train points to check]].
 
'''8. Failure to check for valve spring coil bind at max lift.'''
 
'''8. Failure to check for valve spring coil bind at max lift.'''
  
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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.
 
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.
  
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===Checking clearances===
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'''10. Failure to check for binding at the rocker/stud interface with stamped steel rockers.'''
 
'''10. Failure to check for binding at the rocker/stud interface with stamped steel rockers.'''
  
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*[[Valve train points to check]]
 
*[[Valve train points to check]]
 
*[http://www.crankshaftcoalition.com/wiki/Category:Adjust_valves Adjust valves]
 
*[http://www.crankshaftcoalition.com/wiki/Category:Adjust_valves Adjust valves]
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;Hotrodders forum threads
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*[http://www.hotrodders.com/forum/difference-measured-vs-calculated-coil-bind-clearance-192254.html?highlight=between+single+coil Valve spring coil bind]
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*[http://www.hotrodders.com/forum/rocker-arm-199353.html Valvetrain geometry]
  
 
[[Category:Engine]]
 
[[Category:Engine]]

Revision as of 10:14, 10 June 2012

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