Setting solid lifter lash on a cold engine
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Race Director
Joined: Nov 2000
Posts: 10,340
Likes: 664
From: Beverly Hills (Pine Ridge) Florida
Setting solid lifter lash on a cold engine
As printed in Engine Builder Magazine:
Compensating for a Cold Engine When Adjusting Mechanical Lifter Valve Lash
When installing a new cam, the engine will be cold but the lash specifications are for a hot engine. What should you do on an engine with mechanical lifters? There is a correction factor that can be used to get close.
Engine respond to the actual movement of the valves. Since the valve cannot move until all the running clearance (valve lash) has been taken up, the amount of valve lash you use affects the engine’s performance.
The alloys of certain 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 is made out of cast iron or aluminum.
You can take the “hot” setting given to you in your cam manufacturer's catalog or cam specification card and alter it by the following amount to get a “cold” lash setting:
• Iron Block Iron Heads – Add .002˝
• Iron Block Aluminum Heads – Subtract .006˝
• Aluminum Block Aluminum Heads – Subtract .012˝
Remember this correction adjustment is approximate and is only meant to get you close for the initial start up of the engine. After the engine is warmed up to its proper operating temperature range, you must go back and reset all the valves to the proper “hot” valve lash settings.
Source: Crane Cams
Compensating for a Cold Engine When Adjusting Mechanical Lifter Valve Lash
When installing a new cam, the engine will be cold but the lash specifications are for a hot engine. What should you do on an engine with mechanical lifters? There is a correction factor that can be used to get close.
Engine respond to the actual movement of the valves. Since the valve cannot move until all the running clearance (valve lash) has been taken up, the amount of valve lash you use affects the engine’s performance.
The alloys of certain 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 is made out of cast iron or aluminum.
You can take the “hot” setting given to you in your cam manufacturer's catalog or cam specification card and alter it by the following amount to get a “cold” lash setting:
• Iron Block Iron Heads – Add .002˝
• Iron Block Aluminum Heads – Subtract .006˝
• Aluminum Block Aluminum Heads – Subtract .012˝
Remember this correction adjustment is approximate and is only meant to get you close for the initial start up of the engine. After the engine is warmed up to its proper operating temperature range, you must go back and reset all the valves to the proper “hot” valve lash settings.
Source: Crane Cams
Le Mans Master
Joined: Nov 2008
Posts: 5,691
Likes: 12
From: columbus oh
that pretty much nails it as far as the different metals are concerned
an one can see, it makes really no difference on cast iron assemblies....
even after warm up both the figures for aluminum in the two instances will be right on, excluding small initial wear of new components.....
an one can see, it makes really no difference on cast iron assemblies....
even after warm up both the figures for aluminum in the two instances will be right on, excluding small initial wear of new components.....
Safety Car
Joined: Jan 2006
Posts: 4,786
Likes: 70
From: Park Bench #805 NE Indiana
As printed in Engine Builder Magazine:
Compensating for a Cold Engine When Adjusting Mechanical Lifter Valve Lash
When installing a new cam, the engine will be cold but the lash specifications are for a hot engine. What should you do on an engine with mechanical lifters? There is a correction factor that can be used to get close.
Engine respond to the actual movement of the valves. Since the valve cannot move until all the running clearance (valve lash) has been taken up, the amount of valve lash you use affects the engine’s performance.
The alloys of certain 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 is made out of cast iron or aluminum.
You can take the “hot” setting given to you in your cam manufacturer's catalog or cam specification card and alter it by the following amount to get a “cold” lash setting:
• Iron Block Iron Heads – Add .002˝
• Iron Block Aluminum Heads – Subtract .006˝
• Aluminum Block Aluminum Heads – Subtract .012˝
Remember this correction adjustment is approximate and is only meant to get you close for the initial start up of the engine. After the engine is warmed up to its proper operating temperature range, you must go back and reset all the valves to the proper “hot” valve lash settings.
Source: Crane Cams
Compensating for a Cold Engine When Adjusting Mechanical Lifter Valve Lash
When installing a new cam, the engine will be cold but the lash specifications are for a hot engine. What should you do on an engine with mechanical lifters? There is a correction factor that can be used to get close.
Engine respond to the actual movement of the valves. Since the valve cannot move until all the running clearance (valve lash) has been taken up, the amount of valve lash you use affects the engine’s performance.
The alloys of certain 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 is made out of cast iron or aluminum.
You can take the “hot” setting given to you in your cam manufacturer's catalog or cam specification card and alter it by the following amount to get a “cold” lash setting:
• Iron Block Iron Heads – Add .002˝
• Iron Block Aluminum Heads – Subtract .006˝
• Aluminum Block Aluminum Heads – Subtract .012˝
Remember this correction adjustment is approximate and is only meant to get you close for the initial start up of the engine. After the engine is warmed up to its proper operating temperature range, you must go back and reset all the valves to the proper “hot” valve lash settings.
Source: Crane Cams
