On Tue, 22 Feb 2000 18:14:10 -0800, Dodd, Kelvin wrote:
> 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
> > > > >
> > > >
> > >
> >
When did the MG's start using hadened seats? I think the american built cars
started using unleaded gasoline in about 74 or 75.
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