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Change in valve lash and performance #2169963
10/07/16 11:01 PM
10/07/16 11:01 PM
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KENTUCKY
69CHARGERMD Offline OP
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69CHARGERMD  Offline OP
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Lash hot should be .020,,,,,realized it was at .025 !!
I reset everything to spec.....
Any comments on what effects on performance I might notice ??
Going to the track tomorrow.

Re: Change in valve lash and performance [Re: 69CHARGERMD] #2169972
10/07/16 11:14 PM
10/07/16 11:14 PM
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Australia
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ozymaxwedge Offline
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Too many variables. Who knows it may go slower or faster but more than likely there will not be any difference.


1963 Plymouth Max Wedge
1971 Barracuda
Re: Change in valve lash and performance [Re: 69CHARGERMD] #2170032
10/08/16 12:46 AM
10/08/16 12:46 AM
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Bend,OR USA
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Cab_Burge Offline
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It depends on how consistent the car is and how close the density altitude was and is now at race time shruggy


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: Change in valve lash and performance [Re: 69CHARGERMD] #2170080
10/08/16 02:28 AM
10/08/16 02:28 AM
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Akron, Ohio
ProSport Offline
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Doug I think it's gonna be at least a half second faster grin


1970 Challenger, all aluminum 528 Hemi, HDK suspension, Tremec 5 speed manual
Re: Change in valve lash and performance [Re: 69CHARGERMD] #2170125
10/08/16 09:23 AM
10/08/16 09:23 AM
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Posts: 8,027
Tulsa OK
Bad340fish Offline
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Tulsa OK
Be careful it might slow down!


68 Barracuda Formula S 340
Re: Change in valve lash and performance [Re: 69CHARGERMD] #2170127
10/08/16 09:42 AM
10/08/16 09:42 AM
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Posts: 4,852
KENTUCKY
69CHARGERMD Offline OP
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69CHARGERMD  Offline OP
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Thanks guys.
The correct lash was .020 and unbeknownst to be I had it set at .025. I will see what it does at the "correct" setting for now. Didn't want any uncessary wear if the lash was too loose.
Will see if it picks up or slows down. Thanks guys.

Case of beer to Prosport if it picks up a 1/2 second. Lol. Thanks Bob. wink

Re: Change in valve lash and performance [Re: 69CHARGERMD] #2170134
10/08/16 10:23 AM
10/08/16 10:23 AM
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Tulsa OK
Bad340fish Offline
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If it slows down 1/2 second Prosport has to send you a case of beer lol.

Good luck!


68 Barracuda Formula S 340
Re: Change in valve lash and performance [Re: 69CHARGERMD] #2170497
10/08/16 07:17 PM
10/08/16 07:17 PM
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KENTUCKY
69CHARGERMD Offline OP
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Car picked up all around. Was running 6.42s last week similar air. 6.39 off the trailer. 6.40 second run. 60' seems a bit better. πŸ‘πŸ‘

Last edited by 69CHARGERMD; 10/08/16 07:18 PM.
Re: Change in valve lash and performance [Re: 69CHARGERMD] #2170499
10/08/16 07:20 PM
10/08/16 07:20 PM
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Bend,OR USA
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Cab_Burge Offline
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Every Mopar that I have tighten the lash up on ran faster at the track work Maybe you should try another .003 to .007 tighter now work scope twocents


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: Change in valve lash and performance [Re: Cab_Burge] #2170533
10/08/16 08:41 PM
10/08/16 08:41 PM
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Rittman Ohio
fourgearsavoy Offline
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I still don't understand why cam grinders specify such wide lash specs. I set mine at .012 so it's nice and quiet and it doesn't beat up the rockers and valves.
Gus beer


64 Plymouth Savoy
493 Indy EZ's by Nick at Compu-Flow
5-Speed Richmond faceplate Liberty box
Dana 60
Re: Change in valve lash and performance [Re: fourgearsavoy] #2170583
10/08/16 09:56 PM
10/08/16 09:56 PM
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Charlotte, North Carolina
sgcuda Offline
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Originally Posted By fourgearsavoy
I still don't understand why cam grinders specify such wide lash specs. I set mine at .012 so it's nice and quiet and it doesn't beat up the rockers and valves.
Gus beer


I have seen lash go away when the engine cools down and hang the valves open when too tight. Not a lot, just enough to not allow the engine to start.


[image][/image]
Re: Change in valve lash and performance [Re: 69CHARGERMD] #2170607
10/08/16 10:41 PM
10/08/16 10:41 PM
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KENTUCKY
69CHARGERMD Offline OP
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Ran another 6.39 with bad 60' this time. (1.44 instead of 1.41). Was hoping for a 6.36-7 per my weather station. New best MPH @ 107.5 MPH. Not sure where that came from.

Re: Change in valve lash and performance [Re: 69CHARGERMD] #2170625
10/08/16 11:16 PM
10/08/16 11:16 PM
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Australia
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ozymaxwedge Offline
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Well there you go,,, maybe I should put a little more time into my lash.

How do you guys go setting lash HOT ? Are you getting the temp right up, pulling plugs, covers, finding TDC firing and then starting the process ?
I have always followed the Mopar chart, tdc set 1in 8out rotate 90deg ect.
Buy the time you do all this it is half cold ???????


1963 Plymouth Max Wedge
1971 Barracuda
Re: Change in valve lash and performance [Re: 69CHARGERMD] #2170666
10/08/16 11:54 PM
10/08/16 11:54 PM
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Wi.
old_racer Offline
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set .006 tighter when dead cold with alum heads on iron block , have checked this when hot and it seems to be right on.

Re: Change in valve lash and performance [Re: old_racer] #2170667
10/08/16 11:58 PM
10/08/16 11:58 PM
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Frostbitefalls MN (Rocky&Bullw...
gregsdart Offline
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Originally Posted By old_racer
set .006 tighter when dead cold with alum heads on iron block , have checked this when hot and it seems to be right on.
iagree


8..603 156 mph best, 2905 lbs 549, indy 572-13, alky
Re: Change in valve lash and performance [Re: 69CHARGERMD] #2170669
10/09/16 12:00 AM
10/09/16 12:00 AM
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Ohio
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lockjaw-express Offline
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Greg All,

what would you set cold at with Aluminum block and Aluminum heads with a roller cam?

Mark

Re: Change in valve lash and performance [Re: 69CHARGERMD] #2170671
10/09/16 12:05 AM
10/09/16 12:05 AM
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Australia
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ozymaxwedge Offline
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Thanks Greg and old_racer .


1963 Plymouth Max Wedge
1971 Barracuda
Re: Change in valve lash and performance [Re: lockjaw-express] #2170677
10/09/16 12:14 AM
10/09/16 12:14 AM
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Washington
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madscientist Offline
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Originally Posted By lockjaw-express
Greg All,

what would you set cold at with Aluminum block and Aluminum heads with a roller cam?

Mark



Set it .010-.012 cold and check it hot. If it's still loose, tighten the cold lash to make up the difference.

I've set some all aluminum stuff as tight as .004 cold.

Last edited by madscientist; 10/09/16 12:14 AM.

Just because you think it won't make it true. Horsepower is KING. To dispute this is stupid. C. Alston
Re: Change in valve lash and performance [Re: 69CHARGERMD] #2170678
10/09/16 12:14 AM
10/09/16 12:14 AM
Joined: Jan 2003
Posts: 4,852
KENTUCKY
69CHARGERMD Offline OP
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69CHARGERMD  Offline OP
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Mine is supposed to be .020 Hot,,,,,but did all my adjustments with it Cold.
I am now at .016 COLD
Sounds like I can tighten it up a bit to .014 cold according to old racer and Greg. πŸ‘πŸ‘πŸΊπŸ‘ŠπŸ»
Will keep you guys posted if the car picks up more.

Re: Change in valve lash and performance [Re: lockjaw-express] #2170680
10/09/16 12:17 AM
10/09/16 12:17 AM
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Posts: 373
sandwich IL
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sandwich IL
Mine grows .017 edelbrock hemi heads and world block so if lash Is .024 I set .007...some people here set at zero lash as it will get to .017 hot...be carful as to always warm up before you rev.


70 charger ,all aluminum 528 hemi 727 cope rmvb,680hp 670 tq,full sequential holley hp efi,full hotchkis tvs,qa1 k and lowers,borgeson steering box cass viper 11.75 with cass s-trac dana 3.54
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