Setting Valve Lash

[cudabob496]

I assume if you set the valves hot, then come back the next day, before you put the valve covers back on, and check the lash numbers cold, you can then set
your valves cold from then on, with the cold lash numbers, and still meet the "setting them while engine hot" requirements/specifications?

[Oldschool]

As long as you have the correct lash settings when hot, then check and measure the lash when cold, you can then use the cold measurements to set the lash when the engine is cold....

[cudabob496]

As long as you have the correct lash settings when hot, then check and measure the lash when cold, you can then use the cold measurements to set the lash when the engine is cold....

Cool, my cam is a solid roller, with lash 20 intake, 22 ex.  How much do you think it might change when I take cold readings?

[73EStroker]

My Lunati solid has 0.016 gap and I set it at 0.014 cold.

[Chryco Psycho]

A lot with alum heads

[cudabob496]

 

My Lunati solid has 0.016 gap and I set it at 0.014 cold.

Interesting, I would have thought, when cold, the gap would have gotten bigger, due to the metals
contracting?

[Changin Gears]

Interesting, I would have thought, when cold, the gap would have gotten bigger, due to the metals
contracting?

The aluminum heads expand more than the steel pushrods, this makes the pushrod "shorter", which causes more gap. 

[high perf mopar]

see chart in the attachment for req,,,the chart would not copy/paste...

Compensating for a Cold Engine when Adjusting Valve LashWhen 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.

You can take the "hot" setting given to you in the catalog or cam specification card and alter it by the following amount to get a "cold" lash setting.

 Note: 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.

http://www.crankshaftcoalition.com/wiki/Adjusting_solid_lifters#Compensating_for_a_Cold_Engine_when_Adjusting_Valve_Lash

[StRoKeR]

I set mine .006 cold and when hot they are right at .018- (aluminum block and heads) I also use EOIC for setting lash on my roller cam.

[high perf mopar]

The aluminum heads expand more than the steel pushrods, this makes the pushrod "shorter", which causes more gap.

thanks for explaining that,,i never thought about the pushrod expansion,,makes sense..just set them 4 tousands below the called 4 16 based upon cranes diagram..