Jerry :
I wish I could spread this mailing to everyone but as I understand it, no
one else would be able to view the pictures that I have scanned from my
spare carb for a TR4A application
At the time that I drilled this tapping I did not no where to obtain the
Brass tube that we are so accustomed to seeing on the carbs so I used a #10
Brass screw that I turned down with a drill and file and press fitted into
the carb body. As you can see in the file attachment that I have sent named
SU Bottom.
In the picture that I sent named Retard Tapping SU I attempted to
disclose the tapping through the drilled Hose Nipple(Brass Screw) into the
throat of the carb body on the Intake side of throttle plate not the air
Piston side I placed a piece of stainless wire through the hole so that it
might be more visible.
One can differentiate between a retard tapping by which side of the
throttle plate it is positioned,If it is on the air piston side and on the
top it will drive a vacuum advance unit, if it is on the intake side and on
the bottom it will drive a vacuum retard unit.I hope that this clears this
up on the carb drilling.
As far as the device you described as an external ZS mechanical linkage,
that I believe you are describing the apparatus mounted on the LH side of
the ZS (as you are looking at them)that is actuated at closed throttle, is
for the venting of the float bowl either to the air filter region In the
throttle closed position and to the canister at closed throttle.The only
valve that I am aware of is the thermo valve located in the radiator hose
which I have removed. At this time my vacuum circuit looks just like the
diagram located in the Bentley Manual page 223 (19.15.02C sheet3)bottom RH
with the exception that I have no EGR valve (plugged the head and
Intake),plugged the vacuum tapping for the EGR valve(at the top rear
carb),and omitted that entire vacuum circuit for the EGR.and I have no more
petrol trap.
I called Moss on there conversion they weren't sure that it had a retard
tapping or not but did say that they are running a Biased needle(spring
loaded)with a code I thought I understood to be BHE. I am unable to verify
the existence of this new cut needle does anyone else know of this needle?
These are very expensive carbs!!!
I don't know what everyone else does with there tank vent but I placed
a modified fuel filter on it to keep dirt and insects out of my vent system.
Brooks
74 TR6
Atlanta GA
----- Original Message -----
From: "Jerry Shaw" <jcs104@home.com>
To: <6pack@autox.team.net>
Sent: Friday, August 03, 2001 7:43 AM
Subject: Re: SU HS6 emissions setup
> Dick and Brooks
>
> Thanks for your inputs!
>
> This carb set came off of either a TR3 or early TR4, and probably already
> has the correct needles.
>
> So here's the plan with a couple questions having to do with EGR valves
and
> retard behavior.
>
> 1) I'm taking off all of the cannister stuff, including the anti-run-on
> switch and the radiator mounting bracket and putting it away, then taping
> the switch connection and rerouting the gas tank hose to a convienient
> non-vacuum place.
> 2) I'm going to route the valve cover vent hose through a PCV valve into
one
> of two holes in my intake manifold, which is the same manifold as for my
> ZS's. I assume any PCV valve will suffice (Dick suggested an early TR6
> version), and I think I need an easy-to-obtain brass fitting to do this,
or
> connect it to the cannister vacuum connection.
> 3) Now here's question #1. Do I remove the EGR valve? It had a connection
to
> the ZS's, as well as into one of the two manifold holes. I can just plug
the
> hole in my head (no jokes please), which leads to the exhaust stream, and
> plug the intake manifold hole.
> 4) And here's question #2. Do I just plug up the retard port on the
> distributor, and how do I compensate for the lack thereof? Brooks, you
> mentioned #55 hole on the throttle plate? My distributor is the later
> model with only centrifugal advance, and a retard vacuum diaphram unit.
> According to Bentley, this connection retards ignition timing during
> deceleration by opening a valve and applying vacuum to the distributor
> through a ZS external mechanical linkage and valve. Is it possible to
devise
> a similar valve linkage for SUs? The ZS valve is pretty simple.
>
> Okay, enough for now.
>
> Thanks
> Jerry Shaw
> '74 TR6
----- Original Message -----
From: "Jerry Shaw" <jcs104@home.com>
To: <6pack@autox.team.net>
Sent: Friday, August 03, 2001 7:43 AM
Subject: Re: SU HS6 emissions setup
> Dick and Brooks
>
> Thanks for your inputs!
>
> This carb set came off of either a TR3 or early TR4, and probably already
> has the correct needles.
>
> So here's the plan with a couple questions having to do with EGR valves
and
> retard behavior.
>
> 1) I'm taking off all of the cannister stuff, including the anti-run-on
> switch and the radiator mounting bracket and putting it away, then taping
> the switch connection and rerouting the gas tank hose to a convienient
> non-vacuum place.
> 2) I'm going to route the valve cover vent hose through a PCV valve into
one
> of two holes in my intake manifold, which is the same manifold as for my
> ZS's. I assume any PCV valve will suffice (Dick suggested an early TR6
> version), and I think I need an easy-to-obtain brass fitting to do this,
or
> connect it to the cannister vacuum connection.
> 3) Now here's question #1. Do I remove the EGR valve? It had a connection
to
> the ZS's, as well as into one of the two manifold holes. I can just plug
the
> hole in my head (no jokes please), which leads to the exhaust stream, and
> plug the intake manifold hole.
> 4) And here's question #2. Do I just plug up the retard port on the
> distributor, and how do I compensate for the lack thereof? Brooks, you
> mentioned #55 hole on the throttle plate? My distributor is the later
> model with only centrifugal advance, and a retard vacuum diaphram unit.
> According to Bentley, this connection retards ignition timing during
> deceleration by opening a valve and applying vacuum to the distributor
> through a ZS external mechanical linkage and valve. Is it possible to
devise
> a similar valve linkage for SUs? The ZS valve is pretty simple.
>
> Okay, enough for now.
>
> Thanks
> Jerry Shaw
> '74 TR6
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