Re: alfa-digest V9 #190 - valve clearances

["Thomas Moll" <moltek@domain.elided>]

I have 'heard' of ITB racers running 0.001-0.002 cold just because as Russ
is assuming the clearances on an Alfa Romeo opens up when it gets hot and
they wanted the extra lift. I'm running 0.007 intake and 0.008 exhaust on my
street car with Euro cams since several years back without any problems.

If what we are saying is true then why did the factory specify such loose
settings? Beats me, maybe to have a margin of safety.

Thomas Moll
Seattle, WA


----- Original Message -----
From: <AlfaNeely@domain.elided>
To: <trentkc@domain.elided>; <C2slayman@domain.elided>; <alfa-digest@domain.elided>
Sent: Friday, January 17, 2003 7:33 AM
Subject: Re: alfa-digest V9 #190 - valve clearances


>        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
nterference  -
> > 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
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