Re: alfa-digest V9 #190 - valve clearances

[AlfaNeely@domain.elided]

       I am running my 84 spider SCCA ITB race car at 0.010 intake and 0.012 
inches exhaust.  The rule book requires stock cams, so a bit of extra lift 
helps.  I have had no problems.
       I am not positive, but Alfa valve clearances might open up when hot.  
I am basing this on an assumption that the aluminum will expand more than the 
steel of the valves and open the clearances.  I have never checked one hot.  
I guess I should.  NOTE: This is an OPINION, ungrounded, perhaps in anything 
related to the real world.
       But IF the clearances open up when the engine warms, then the valves 
are less likely to burn.  But if that were true, why did the factory not 
specify tight settings when the engine is cold?

Ciao,
Russ Neely
Oklahoma City



In a message dated 01/17/2003 9:05:00 AM Central Standard Time, 
owner-alfa-digest@domain.elided writes:


> Date: Fri, 17 Jan 2003 03:15:23 EST
> From: C2slayman@domain.elided
> Subject: Re: valve clearances
> 
> Kevin,
>        The problem with tight valve clearance is not piston interference  - 
> I 
> don't think a few mills is going to make the difference between bent valves 
> or not.  But if the clearance goes to zero, your going to burn valves!  So 
> if 
> you run on the tight side, check your clearance regularly.
> 
> Charlie
> 
> > Date: Sun, 12 Jan 2003 13:31:43 -0500
> > From: Kevin Trent <trentkc@domain.elided>
> > Subject: Re: valve clearances
> > 
> > I always lean to the tight side for the additional lift, and just set up 
> a 
> > 1750 head on a rebuild project with the lash set at .015 intake and .017 
> > exhaust.   I have a 2L that is set at .014 and .016.  Perhaps some more 
> > knowledgeable digester can provide reasons why this is not a good 
> practice 
> > - - the most obvious is the possibility for insufficient piston 
> > clearance.  It would seem to me that an important consideration is 
> > uniformity across cylinders, but I don't know how many thousandths would 
> > make a difference until cylinder "inequality" would affect how the engine 
> > runs.
> > 
> > //KCT, Powell, TN
--
to be removed from alfa, see /bin/digest-subs.cgi
or email "unsubscribe alfa" to majordomo@domain.elided