I've been considering multiple carbs vs. "Petrol Injection" (don't you just
love it), since I now own two TR6s, one driver and one toy. I just completed
a dual ZS to 1 3/4 " SU conversion on one, and after sleeping for 11 years,
my newly acquired '74 sprang to life on the first attempt to start it (after
prudent prep, of course).
As Glen Johnson says, however, just because SUs are easy to get going,
doesn't mean that they run optimally, so I've been also considering O2
sensors. So far, having not read, "How to Power Tune SU Carbs" yet, I've
found an interesting Web reference to practical advice on using O2 sensors
to tune SU carbs on Morgans by Fred Sisson:
http://www.team.net/www/morgan/tech/tuning.html . Note the reference to
SUNEEDLE, a DOS program that has a built in catalog of the umpty-ump SU
needles available.
Since I'm an experimentalist by training and inclination, I was intrigued by
the possibility of rolling my own O2 sensor read-out head, using either a
Radio Shack digital VM (I can velcro it to my dash) or an untested circuit
proposed by Dave Morrill http://www.team.net/www/morgan/tech/O2_LED.html
These are alternatives to buying the $100 versions from Racer Wholesale
Parts. In all cases, I'd pick up the 3-wire O2 sensor from JCWhitney or
others, since I understand that they're more responsive.
So the question is where in the exhaust path to place the sensor(s), since I
plan on dual SS headers and the sport exhaust system. Do you buy two sensors
and have the threaded adapters welded into the headers and use a switch or
what?
Anyone done this?
Jerry Shaw
'74 TR6 Sapphire Blue
'75 TR6 BRG
----- Original Message -----
From: "Sally or Dick Taylor" <tr6taylor@webtv.net>
To: "Glen Johnson" <glen@littledevil.com.au>
Cc: <6pack@autox.team.net>
Sent: Wednesday, September 05, 2001 3:06 AM
Subject: Re: Triple Webers
> Glen---If you haven't as yet given up on the 1.75 SU's, get hold of the
> manual "How to Power Tune the SU Carburetor". It makes balancing
> multiple carbs easy, and even how to modify the needles to suit
> yourself.
>
> Add an 02 sensor to the exhaust and A/F monitor where you can read it,
> and you will know where the "flat spots", or over carburetion is
> occuring. The 'monitor' is good to have regardless of which system you
> end up with.
>
> Dick Taylor
> L.A., Ca.
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