James:
If the valves are kept adjusted correctly so that the seats arn't
hammered to death the original as cast seats hold up for a fair time. When
the factory went to unleaded, the seat areas were hardened slightly by heat
treating, but inserts were not used.
From my experience with unleaded fuel, I was getting about 20,000
miles out of the original seats following a valve and seat grind. Then the
seats were so recessed that the valves would not stay adjusted. At that
point the heads were replaced with less worn ones. I now have a pair of 18V
heads with exhaust seats completely worn out. Installing hardened seats is
a simple way to rejuvinate the head once it is worn out.
Keep in mind that valve and seat wear and failure is a combination
of factors. Valve train geometry, spring rate, fuel mixture, cooling,
maintenance etc. A little extra money spent at rebuild time tends to give
you more miles of carefree driving and a wider margin for error.
Kelvin.
> -----Original Message-----
> From: James Nazarian Jr [mailto:James.Nazarian@Colorado.EDU]
> Sent: Tuesday, February 22, 2000 5:57 PM
> To: Dodd, Kelvin
> Cc: James Nazarian Jr; mgs@autox.team.net
> Subject: RE: No lead
>
>
> So what you are saying is that I probably should have converted my '71
> when I put it on the road 5 years ago? I blew the head
> gasket racing last
> fall and replaced that and cleaned head, no holes and no minions but I
> think they are being eaten by the rust worms.
>
> James Nazarian
> '71 B roadster
> '71 BGT rust free and burnt orange
> '74 BGT going by-by soon
> '63 Buick 215
>
> On Tue, 22 Feb 2000, Dodd, Kelvin wrote:
>
> > James:
> >
> > The first indication of a problem is that the valves need
> to be adjusted
> > more often. This is fun the first time or two. When your
> lady complains
> > that she can't hear you over the clatter of the engine then
> beans you with a
> > handbag you realize that the world is no longer a friendly
> place. Shortly
> > thereafter holes appear in the edges of the exhaust valves,
> Cthulu's minions
> > crawl from the dark nether regions of the earth and the
> echo's of screams
> > replace the flatulant gasps of fumes pushed past worn out
> valve seats.
> >
> > In three words. Aggravated Valve Recession.
> >
> >
> > Kelvin.
> >
> > >
> > > What happens if nothing is done to convert? Do you burn
> oil or burn
> > > valves or what? Or will the entire universe collapse?
> > >
> > > James Nazarian
> > > '71 B roadster
> > > '71 BGT rust free and burnt orange
> > > '74 BGT going by-by soon
> > > '63 Buick 215
> > >
> > > On Sun, 20 Feb 2000, Charley & Peggy Robinson wrote:
> > >
> > > > Hi Carl,
> > > >
> > > > Haven't been on in a while, so just saw yer post. Best
> > > intelligence
> > > > I've received so far is that you need to have hardened
> valve seats
> > > > installed in AT LEAST the exhaust side of your head.
> You can run
> > > > stainless or stellite exhaust valves. I'm running
> > > stellites; lots of
> > > > cars running stainless.
> > > >
> > > > CR
> > > >
> > >
> >
>
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