valve lash setting
#1
Junior Member
JOURNEYMAN
Thread Starter
Join Date: Nov 2006
Location: san antonio,texas
Posts: 28
valve lash setting
I just bought a new set of AFR heads, and as i was reading there directions, It said to run the valve lash .006 tighter than normal. I am running aluminum heads on a iron block.
i have never heard of this, is this true??????
i have never heard of this, is this true??????
#2
Senior Member
DYNO OPERATOR
Join Date: Apr 2008
Posts: 504
Cold valve lash with aluminum heads will measure about .006 greater when they heat up so when the engine is fresh you set the lash at .006 tighter cold to get started. Always lash the engine hot for an accurate final setting. The head will expand at different rates along the head due to thermal mass and unequal heating which is the condition that the engine runs in. Always do the lash and check it at the same temp every time. The hotter temp that you set them at the tighter they will be when cold.
Bruce
Bruce
#3
Senior Member
RACING JUNKIE
Join Date: Jun 2003
Location: Hobbs, NM
Posts: 842
Originally Posted by TopspeedLowet
Cold valve lash with aluminum heads will measure about .006 greater when they heat up so when the engine is fresh you set the lash at .006 tighter cold to get started. Always lash the engine hot for an accurate final setting. The head will expand at different rates along the head due to thermal mass and unequal heating which is the condition that the engine runs in. Always do the lash and check it at the same temp every time. The hotter temp that you set them at the tighter they will be when cold.
Bruce
Bruce
#5
Senior Member
RACING JUNKIE
Join Date: Jul 2007
Location: Independence, Missouri
Posts: 1,181
Originally Posted by Tod74
Just set them cold.Once it warms up check them and see how much they changed and then do the math....I set mine at .016 cold and when it warms up they are .022-.023 . Iron block aluminum heads.
#8
Junior Member
JOURNEYMAN
Thread Starter
Join Date: Nov 2006
Location: san antonio,texas
Posts: 28
i always have just brought it to temperture and set the valves,never had any problems. i did not no about the .006 tighter for alum heads.
30 years of doing this and still learning. no wonder i am still slow !!!!
Thanks for the imfo-----
30 years of doing this and still learning. no wonder i am still slow !!!!
Thanks for the imfo-----
#9
Senior Member
RACING JUNKIE
Join Date: Jun 2003
Location: Hobbs, NM
Posts: 842
Originally Posted by nova77
i always have just brought it to temperture and set the valves,never had any problems. i did not no about the .006 tighter for alum heads.
30 years of doing this and still learning. no wonder i am still slow !!!!
Thanks for the imfo-----
30 years of doing this and still learning. no wonder i am still slow !!!!
Thanks for the imfo-----