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Valve lash how tight? #228509
02/18/09 10:01 AM
02/18/09 10:01 AM
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emarine01 Offline OP
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On a solid roller that specs out for lash @ .020I & .022e hot , how much tighter can you safley go?

Re: Valve lash how tight? [Re: emarine01] #228510
02/18/09 10:10 AM
02/18/09 10:10 AM
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BobR Offline
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I've run .010/.012 with no problems. It will change the cam performance slightly.

Re: Valve lash how tight? [Re: BobR] #228511
02/18/09 11:04 AM
02/18/09 11:04 AM

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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

Re: Valve lash how tight? [Re: ] #228512
02/18/09 11:10 AM
02/18/09 11:10 AM
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emarine01 Offline OP
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I was thinking cuting back .010 on both ,trying to cheet on a small cam a bit

Re: Valve lash how tight? [Re: emarine01] #228513
02/18/09 01:26 PM
02/18/09 01:26 PM
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The tight lash cams can not be ran as tight as the loose lash cams can, I wouldn't start with ten thousands on your cam as it is in the middle of being a tight or loose lash cam. I would try .004 to .007 and see what the motor does and then try a little tighter if the motor repsonds to the tighter lash


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: Valve lash how tight? [Re: emarine01] #228514
02/18/09 01:47 PM
02/18/09 01:47 PM
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The cam designer specified that lash for a reason. I wouldn't change it.

Re: Valve lash how tight? [Re: AndyF] #228515
02/18/09 02:15 PM
02/18/09 02:15 PM
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emarine01 Offline OP
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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

Re: Valve lash how tight? [Re: emarine01] #228516
02/18/09 02:32 PM
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BobR Offline
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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.

Re: Valve lash how tight? [Re: BobR] #228517
02/18/09 02:44 PM
02/18/09 02:44 PM
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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
Re: Valve lash how tight? [Re: Rapid340] #228518
02/18/09 02:54 PM
02/18/09 02:54 PM
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emarine01 Offline OP
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I learned that on the hard way, I think I beat the lash caps in on 3 valves when we were opening up lash on a 280/284 @ .050 cam

Re: Valve lash how tight? [Re: emarine01] #228519
02/18/09 04:41 PM
02/18/09 04:41 PM
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One more thing to watch for is a piston/valve clearance change. If you are already close this is much more of an issue.

Re: Valve lash how tight? [Re: BobR] #228520
02/18/09 06:00 PM
02/18/09 06:00 PM
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Brookeville, Md
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wow I just did my 528 solid w/ 1.5 rollers at .026/.030...maybe I should go re-do them

Re: Valve lash how tight? [Re: emarine01] #228521
02/18/09 07:21 PM
02/18/09 07:21 PM

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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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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.


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