british-cars
[Top] [All Lists]

TR-8 emmissions

To: sol@hoosier
Subject: TR-8 emmissions
From: Lawrence Buja <mit-eddie!CC.UTAH.EDU!ccm0b%PURCCVM.BITNET@EDDIE.MIT.EDU>
Date: Mon, 13 Aug 1990 10:41 EST
 
To: barry@sybase.com
Re: TR8 Air Pump
 
    (e-mail to Barry Klawans bounced, so i'm posting it thru SOL.)
 
    The reason that my recent posting seemed oblivious to your first
 note (Fri.  Jul 27 ) is because it was--I don't have access to the
 net directly.  I mail a disk to my brother Lawrence who posts them
 for me, so I had no idea that you were looking for information on an
 air pump.  I hope this information arrives in time for you to make a
 decision about purchasing an 8.
 
     I have a 1980 TR8 convertible, with twin carbs, and manual gearbox.
When I removed the air pump from the car, I was able to remove a plastic
filter and found the following information cast into the drive-end
face of the air pump:  7826366 CAV 8   K (The K was upside down in
relation to the previous string of characters.)  There was a date grid
that indicated that the unit was manufactured in the 4th week of January
79.  On the back plate was cast the following: A       8352
                                               S    7817872
The 8352 was upside-down as compared to the 781782, and the letters AS
were each rotated 90 degrees clockwise from the way I've shown them
here.  There was a machined boss on the case of the air pump that had
the number 205192 stamped into it.
    Since the TR8 repair manual gave no information about servicing the
air pump, I looked in a few shop manuals in my local Whitlock autoparts
store.  I found a 1982 Oldsmobile shop manual that had an air pump that
looked exactly like mine, but since I don't have an early 1980s GM car,
I've provided the above information so that you can rummage around
under the hoods of some early 80's GM cars to see if the air pumps
installed in them are comparable with the TR8 installation.  Your local
salvage yard may be able to satisfy your needs....
 
    As to your request for a shop manual, try The Roadster Factory.  The
TR8 Repair Operations Manual is available as part number AKM3971 and was
priced at $39.95 in the latest TRF publication (Triumph Newsletter,
dated May 7, 1990).  This manual is worth every penny--I cannot
recommend it highly enough!  Seriously, it does lack some disassembly
details as compared to GM and Ford shop manuals, but it is many times
better than the Bentley manual that I had for my GTI and a thousand
times better than the factory Saab manual that I had for my '83 900.
 
    The Repair Operations Manual gives a concise description on the
operation of the air injection system, but it seems to have been
copied from a TR7 manual as it describes the operation of a diverter
valve during high manifold vacuum to prevent backfire in the exhaust
system during the temporarily rich mixture experienced during rapid
throttle closure.  This system seems to be exclusive to the TR7--no
diverter valve is present on the TR8.
 
    The stock emissions setup on a 1980 TR8 seems to have included the
following equipment:
                Federal                       California
 
Fuel/Exhaust:   Twin carbs (Z-S 175 CDSET)    Lucas-Bosch Digital Fuel
                with air pump, twin           Injection with oxygen
                catalysts                     sensors, twin (3-way?)
                                              catalysts
 
Distributor:    Lucas electronic, type 35DE8  same
 
EGR Valve:      in left exh. manifold         in right exh. manifold
 
Evaporative
Loss controls:  Twin charcoal canisters       same
 
Crankcase
ventilation:    canister to LH valve cover    filter in LH valve cover
                through crankcase to RH       through crankcase to RH
                valve cover to constant       valve cover to constant
                vacuum area of carbs          vacuum area between air
                                              metering flap & throttle
 
Air Injection:  Twin vane positive            none
                displacement air pump,
                one pressure relief valve,
                two check valves (one per
                air manifold on each exhaust
                manifold), eight air injectors
                (downstream from the exhaust
                valves, facing upstream) in
                the exhaust manifolds
 
    The catalytic converters differ between the Federal and California
models, both in size and physical appearance.  The latest version of
Victoria British's TR7 and 8 catalog shows the exhaust systems for all
versions in fairly good detail.  The Roadster Factory's TR7 and 8
catalog shows even greater detail as to how the hardware fits together,
although it is a bit tougher to decipher dates as to when changes were
made.  I think that the catalysts used with fuel injection are 3-way
units that control CO, NOx and HC because they are used with oxygen
sensors.  If you look closely enough in the catalogs that I mention
above, you'll notice that the California converters are larger in both
diameter and length, and that the Fuel Injection catalysts include
the intermediate pipe.  The Carb. models have a separate intermediate
pipe between the catalyst and center mufflers.
     You may be asking why there are California carburetor catalysts--it
seems that in some cases, Federal models were equipped with "California"
emissions spec engines.  This would be indicated by the engine number
starting with 12E or 13E.  The engine number is found on the left side
of the engine, below the exhaust manifold.  In my case, I have a
Federal model (carbs), but have an engine number beginning with 12E.  I
have California-type (large) catalysts and separate intermediate pipes.
Confused?  I still am....    Maybe there is someone out in the net who
knows what the reasoning would be for this confusion....
 
          Tim Buja                          Cherry Valley, IL


<Prev in Thread] Current Thread [Next in Thread>
  • TR-8 emmissions, Lawrence Buja <=