Adjusting solid lifters
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| − | == | + | ==Adjusting the lash== |
| + | {{Note1}}Expect the lash to change (often it will tighten) on a new cam and lifters (not a lot, but noticeable) until the valve train is bedded in together. Once this is done, you'll not be needing to adjust the lash very often, although you still need to occasionally check the lash. A good time to check the lash is at oil change intervals. | ||
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*In many cases the hot lash setting may be used for initial start-up unless the manufacturer's instructions say to do otherwise. If there's any question as to what cold lash to use for start up, refer to manufacturer's instructions. | *In many cases the hot lash setting may be used for initial start-up unless the manufacturer's instructions say to do otherwise. If there's any question as to what cold lash to use for start up, refer to manufacturer's instructions. | ||
*After the engine is hot, the valves get adjusted to their correct hot lash setting. *Then after a '''complete''' cool-down (overnight is preferred), the lash is remeasured and recorded for future use when checking/setting the lash ''cold''. That will get it '''right''' as opposed to ''close''. | *After the engine is hot, the valves get adjusted to their correct hot lash setting. *Then after a '''complete''' cool-down (overnight is preferred), the lash is remeasured and recorded for future use when checking/setting the lash ''cold''. That will get it '''right''' as opposed to ''close''. | ||
| − | + | ==Cold adjustment for first start up== | |
| + | Because all engines are different, be sure to use this as a guide only. Checking what your engine does is important because of the variables involved. | ||
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| + | ===Comp Cams=== | ||
| + | ;Setting Solid Lifter Valve Lash | ||
| + | Consult the cam spec card for the correct lash specification. All COMP Cams® spec cards list the “hot” (operating temperature) lash setting, but it will also work for initial start-up. | ||
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| + | ===Crane=== | ||
| + | The same basic adjustment procedure should be used for mechanical lifter cams. Instead of lifter preload, you must use the clearance specs on the cam card for your cam. | ||
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| + | Also see '''[[Adjusting solid lifters#Compensating for a Cold Engine when Adjusting Valve Lash|Info from Crane]]'''. | ||
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| + | ===Lunati=== | ||
| + | To adjust VALVE LASH ON MECHANICAL (solid) LIFTER CAMS, follow the same basic procedure as above (adjust with lifter on base circle of cam). Instead of hydraulic lifter | ||
| + | pre-load and zero lash, use the valve lash specs printed on your Lunati cam spec card. After engine start-up and break-in, change the oil and filter, and verify the valve lash settings. You’ll need to check this periodically based on vehicle usage. (The | ||
| + | valve lash settings noted on the spec card are “HOT” settings, and will need to be verified with the engine at operating temperature.) | ||
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On a SBC and most other V8s, you can cut the center out of an old valve cover to use when setting lash hot, engine running. It will keep most of the oil from splashing out. You would use 45 degree bent feelers (or bend them yourself), and if you use polylocs, using a valve adjusting tool like shown below can make things easier. A tool like that can even help when setting the lash cold because it's easier to get the same 'feel' from valve to valve. | On a SBC and most other V8s, you can cut the center out of an old valve cover to use when setting lash hot, engine running. It will keep most of the oil from splashing out. You would use 45 degree bent feelers (or bend them yourself), and if you use polylocs, using a valve adjusting tool like shown below can make things easier. A tool like that can even help when setting the lash cold because it's easier to get the same 'feel' from valve to valve. | ||
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[[File:Go-no go valve feeler.jpg]] | [[File:Go-no go valve feeler.jpg]] | ||
| − | ==Info from Crane | + | ==Info from Crane== |
All pushrod engines using mechanical (solid) lifters, or mechanical roller lifters, must have an adjustable valve train so that precise adjustment for "Valve Lash" can be made to match the camshaft's requirements. Valve lash is the running clearance that exists between the tip of the valve stem and the valves mating surface of the rocker arm. (It is expressed in the Crane Catalog as "Valve Lash" and on the camshaft specification card as "Valve Setting". Both terms mean the same thing.) | All pushrod engines using mechanical (solid) lifters, or mechanical roller lifters, must have an adjustable valve train so that precise adjustment for "Valve Lash" can be made to match the camshaft's requirements. Valve lash is the running clearance that exists between the tip of the valve stem and the valves mating surface of the rocker arm. (It is expressed in the Crane Catalog as "Valve Lash" and on the camshaft specification card as "Valve Setting". Both terms mean the same thing.) | ||
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For this reason, Crane requires that the valve lash be set with the engine "Hot" on all pushrod engines using mechanical lifters. This will insure that the minimum required clearance (valve lash) is maintained throughout the engine's operating temperature range. | For this reason, Crane requires that the valve lash be set with the engine "Hot" on all pushrod engines using mechanical lifters. This will insure that the minimum required clearance (valve lash) is maintained throughout the engine's operating temperature range. | ||
| − | + | ===Compensating for a Cold Engine when Adjusting Valve Lash=== | |
When installing a new cam, the engine will be cold but the lash specifications are for a hot engine. What are you to do? There is a correction factor that can be used to get close. We mentioned that the alloy of the engine parts can be affected by thermal expansion in different ways, therefore the amount of correction factor to the lash setting depends on whether the cylinder heads and block are made out of cast iron or aluminum. | When installing a new cam, the engine will be cold but the lash specifications are for a hot engine. What are you to do? There is a correction factor that can be used to get close. We mentioned that the alloy of the engine parts can be affected by thermal expansion in different ways, therefore the amount of correction factor to the lash setting depends on whether the cylinder heads and block are made out of cast iron or aluminum. | ||
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