John has a 1980 spitfire. I think you are correct for engine numbers up to
109090. After which, a "air distribution manifold" or air rail was used.
>From the pump to a one way check valve (to prevent damage to the pump in the
case of a backfire or a broken belt). The tube travels around the back of
the engine, having a support bracket at the right rear head stud. Four
smaller tubes branch off the rail and enter at the surface of the head. The
purpose was/is to combine pressurized air with exhaust gases and "...assist
in making more complete the oxidization process in the exhaust system."
Currently, emission standards for the state of Pennsylvania are with respect
to metropolitan areas only. There are no testing/requirements in rural,
outlying areas.
Ed Hamilton
----- Original Message -----
From: <Growe58@aol.com>
To: <spitfires@autox.team.net>
Sent: Monday, September 27, 1999 12:53 PM
Subject: Re: Amateur Confusion
>
> Hi, John.
>
> On the federal 78s, a rubber hose exits from the back of the air pump,
> runs behind the engine into a one way check valve (prevents backfires from
> damaging the air pump), into a metal pipe that fits directly into the
manifold
> above the converter and below the four branches. I think that the idea
was
> to provide air for additional combustion of the mixture and maybe some
> dilution for the cat.
>
> Trouble with the manifolds is that they break easily (ask me how I know)
due
> to the weight of the cat. There is a bracket and clamp to provide
additional
> support on the bellhousing, but this often breaks itself or is removed
(ask me
> how I know). These exhaust manifolds are therefore somewhat difficult to
> obtain
> at this point (ask me how I know). That may be why a header is fitted.
>
> I assume that the header means that your cat converter and EGR valve are
> also missing? I didn't notice what state you're from, but I can tell you
> (from
> expereince) that a properly tuned spit can pass a tail pipe sniff test
> WITHOUT
> the emissions equipment. Unfortuneatly some states also require and verify
> that the emissions equipment is in place, as PA now does ...
>
> Good luck!
>
> Greg Rowe
> 78 Spit
>
>
>
> In a message dated 9/27/1999 9:39:35 AM EST, JOrwin308@aol.com writes:
>
> > So, I am trying to figure out where the air rail is supposed to tap
into.
> > The head on the engine does NOT have passages for the air rail to bolt
> into.
> >
> > Is it supposed to bolt into the head, or the exhaust manifold? It is a
> > Federal model if that makes a difference. Someone please tell me I
don't
> > need to replace the head as well!
> >
>
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