Surely there is room way at the back of the car near the rear muffler. Or
is it too cool to be useful by then? Why couldn't they have done it like
BMW did in the Mid-70's with a Thermal Reactor and no cat.
Peter s
----- Original Message -----
From: John Weale <tyre@u.washington.edu>
To: Atwell Haines <carbuff@nac.net>
Cc: Rick Gregory <rick_gregory@yahoo.com>; <spitfires@autox.team.net>
Sent: Monday, June 14, 1999 8:55 PM
Subject: Re: air pump
>
> I've been slogging through the smog check nightmare for a while,
> so I just had to chime in...
>
> On Mon, 14 Jun 1999, Atwell Haines wrote:
>
> >
> > At 08:09 AM 6/14/99 -0700, you wrote:
> >
> > Can't say. I know that mine goes put-put-put with the pump
disconnected.
> > I think the check valve's purpose is to prevent hot exhaust gases from
> > ruining the pump itself.
> That's in line with the 'official' Repair Operation Manual claim:
> "Check Valve: The check valve is a one-way valve positioned between the
> diverter and relief valve and the air manifold. Its purpose is to protect
> the pump from back-flow of exhaust gases. The valve closes if the pump
> pressure falls while the engine is running, should, for example, the dreve
> belt break." It also mentions that the relief valve is integral to the
> pump on later models.
>
>
> > >
> > >How could the catalytic converter be the cause of the
> > >problem? Restricted flow?
> >
> > I think so. (I don't claim to be an expert here.) When a carb runs rich
the
> > Cat overheats and literally 'melts' down into a lump. Instead of flowing
> > the exhaust through it, it blocks the gassy, hot mixture & it ignites.
> >
> I'm not sure it 'melts' down. Having just had the unfortunate
> chance to look at a failed Spit cat, it looks like a unmelted honey comb
> ceramic matrix crumbled into a pile of broken bits inside the can. No
> signs of melting, just shattering (this is on my 1980 Spit -- I replaced
> the manifold to get ready for a smog check and noticed my dead converter
> in the process:( ).
>
> There is a lot to this emissions garbage I'm finding. I think the
> gulp valve is being confused with the diverter valve in some of the
> anti-backfiring discussions, but I'm not following close enough to dare
> try to correct anyone :) (the gulp apparently gives a shot of air into
> the intake during sudden deceleration -- luckily, my '80 has the direct to
> manifold connection rather than the air rail w/ gulp valve *and* the
> diverter/check valve integral to the air pump so I don't have to worry
> about all the bits)(at least that's what I'll claim at the smog check
> station, now if only my cat was actually working I'd be set).
>
> A final note on catalytic converters, I checked with an exhaust
> shop today and they couldn't do anything with the Spit converter since all
> their custom or generic converters are for welding into a straight pipe.
> The way the Spitfire cat is also the flange that mates to the manifold
> seems to make it hard to kludge with a generic replacement (bummer, since
> the generic is $100 vs. $300 for a Spitfire one).
>
> John Weale
> 1980 "British Racing Orange" Spitfire
>
> ---======================== John Weale(tyre@u.washington.edu)
==========---
> The world does revolve around engineers... they pick the coordinate
system.
>
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