aluminum 426 hemi cold valve lash
#1335960
11/16/12 12:57 AM
11/16/12 12:57 AM
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Joined: Jan 2012
Posts: 2,636
Stuttgart, Arkansas
rickseeman
OP
master
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OP
master
Joined: Jan 2012
Posts: 2,636
Stuttgart, Arkansas
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On a cast iron hemi with aluminum heads I set the valve lash at -7 to be correct when it is hot. What do I set it at cold with a Keith Black aluminum block and aluminum heads? Thanks for youir help.
2011 Drag Pak Challenger
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Re: aluminum 426 hemi cold valve lash
[Re: rickseeman]
#1335964
11/16/12 10:03 AM
11/16/12 10:03 AM
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Joined: Jan 2003
Posts: 13,357
Marion, South Carolina [><]
an8sec70cuda
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 13,357
Marion, South Carolina [><]
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I set mine .013" tighter when cold. I lash em at .010" cold so I have .023" hot. KB block, MP heads. 
CHIP
'70 hemicuda, 575" Hemi, 727, Dana 60
'69 road runner, 440-6, 18 spline 4 speed, Dana 60
'71 Demon, 340, low gear 904, 8.75
'73 Chrysler New Yorker, 440, 727, 8.75
'90 Chevy 454SS Silverado, 476" BBC, TH400, 14 bolt
'06 GMC 2500HD LBZ Duramax
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Re: aluminum 426 hemi cold valve lash
[Re: B G Racing]
#1335967
11/16/12 12:56 PM
11/16/12 12:56 PM
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Joined: Jan 2003
Posts: 1,938
Sonora CA
Mopar_Rich
top fuel
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top fuel
Joined: Jan 2003
Posts: 1,938
Sonora CA
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Quote:
Expansion rate on a all aluminium engine is .015/.018.This can be subtracted from the recommended hot lash setting,but never go tighter than .005. Example:If the hot lash is .026int..028 exh.Then set int.at .011 and the exh.at.013.Then check lash hot.By doing this you can determine the actual expansion rate and zero in on the correct cold setting.
I agree, but it also might matter where you live and how cold it might get when starting. For example, I have customers that have to start their aluminum engines in the winter when it's 30 degrees in their shop. With a World block and Stage-V heads I set the cold lash at .005 (when very cold) just so the valves will actually close. After warm up I typically see about .020 and .024.
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Re: aluminum 426 hemi cold valve lash
[Re: Mopar_Rich]
#1335968
11/16/12 01:33 PM
11/16/12 01:33 PM
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Joined: Mar 2006
Posts: 9,910
Eighty Four, PA
B G Racing
master
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master
Joined: Mar 2006
Posts: 9,910
Eighty Four, PA
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Quote:
Quote:
Expansion rate on a all aluminium engine is .015/.018.This can be subtracted from the recommended hot lash setting,but never go tighter than .005. Example:If the hot lash is .026int..028 exh.Then set int.at .011 and the exh.at.013.Then check lash hot.By doing this you can determine the actual expansion rate and zero in on the correct cold setting.
I agree, but it also might matter where you live and how cold it might get when starting. For example, I have customers that have to start their aluminum engines in the winter when it's 30 degrees in their shop. With a World block and Stage-V heads I set the cold lash at .005 (when very cold) just so the valves will actually close. After warm up I typically see about .020 and .024.
 No tighter than .005,I don't recommend anyone trying to start a race engine at below 30 degrees.I suggest some type of engine coolant heater or other means of bringing up the temperture.It's tough to control any race fuel or oil stability at that cold of temperture. 
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