Re: Valve lash how tight?
[Re: BobR]
#228511
02/18/09 11:04 AM
02/18/09 11:04 AM
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Anonymous
Unregistered
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Anonymous
Unregistered
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With aluminum heads the lash will always change so check it HOT and too tight can and will slow you down--you have to have enough room for it to shut that valve at high RPM---I sent one out ran 5.60 all day long--next week started 5.90--still ran fine but where did all that ET go? Come to find out the customer had the valves too tight--more lash and back to 5.60 again
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Re: Valve lash how tight?
[Re: emarine01]
#228516
02/18/09 02:32 PM
02/18/09 02:32 PM
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Joined: Oct 2004
Posts: 8,165 Left Coast
BobR
master
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master
Joined: Oct 2004
Posts: 8,165
Left Coast
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Quote:
Just got off the phone with comp cams , tightest lash .010/.012 hot , so looks like .010 is the ticket Will make cam seem 2 to 3 degrees larger
Why that sounds familiar. And IMo there is nothing wrong with experimenting with lash. I've done it successfully several times over the years.
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Re: Valve lash how tight?
[Re: BobR]
#228517
02/18/09 02:44 PM
02/18/09 02:44 PM
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Joined: Sep 2004
Posts: 2,091 oberlin, Ohio
Rapid340
top fuel
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top fuel
Joined: Sep 2004
Posts: 2,091
oberlin, Ohio
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That is one of the nice things with a solid, you can adjust lash on intake and exhaust independantly and experiment.
BTW, be carefull on opening up lash too much, I would limit it to four or five thousanths more than the recomended lash.
1971 Factory Appearing Duster 340 11.000 @ 122 mph
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Re: Valve lash how tight?
[Re: emarine01]
#228521
02/18/09 07:21 PM
02/18/09 07:21 PM
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Anonymous
Unregistered
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Anonymous
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It was suggested to me to run about 6 to 8 thous. tighter with aluminum heads. I have a MP 590 cam, and is suppose to be 28-32 and I run them at 20-24 and it seems to run fine. I checked them several times and they stayed right on the numbers. Some racers ran them much tighter than that and said the car went faster. I'm just not williing to take that much of a chance. With indy heads cut down to 69 cc and a 0 decked block they had enough clearance at were I set them.
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Re: Valve lash how tight?
[Re: emarine01]
#228522
02/18/09 08:15 PM
02/18/09 08:15 PM
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Joined: Jul 2004
Posts: 19,317 State of confusion
Thumperdart
I Live Here
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I Live Here
Joined: Jul 2004
Posts: 19,317
State of confusion
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I have an isky solid roller w/.680-.660 lift and 275-280 dur@ .050 and the cam card calls for .026 hot in. and ex. I`ve set em that loose and can`t stand the rattle and it sounds like it`s coming apart so now I set em at .014(cold) and they end up at around .019-.020(hot) and runs the best so far.
72 Dart 470 n/a BB stroker street car `THUMPER`...Check me out on FB Dominic Thumper for videos and lots of carb pics......760-900-3895.....
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