You are correct in your understanding that the lead in race gas is bad for
the O2 sensor. People have tried to resurrect them after fouling with a
torch. I personally have not done this.
Regarding EGT (Exhaust gas temp.) themocouples and gauges. I use two sending
unit one the #1 and one on the #4 header pipes. These are quite small and only
the tip is inside the tube. The temperature readings are great way of
seeing if the air/fuel mixture is even at LOAD. But I always correlate them
with the plugs.
In fact at a recent race for whatever reason the number 4 cyl. exhaust
was way too cool and I compensated by asymetriclally jetting the webber.
It really made a difference. Now why was that cyl cooler is still not
clear.
Mordy Dunst
______________________________ Reply Separator _________________________________
Subject: Oxygen sensors or Exhaust Gas Temps
Author: Malcolm Cox <malcox@napanet.net> at INTERNET
Date: 9/8/96 11:41 PM
Im getting an urge to fiddle with my carbs, but have been advised it may stunt
my
pistons.
Specifically, @ 12:1, I have heard that there seems to be great risk of erring
on
the lean side
and perforating same.
On the shallow face of it, it seems that an Oxygen sensor would be a foolproof
me thod of getting
the mixture right, presumably one for each carb/exhaust combo would be spiffing.
However
these sensors seem to be big and cannot stand leaded racing gas for long and so
w ould only be
useful for an occasional test and tune session.
On the other hand, fitting exhaust gas sensors could also be useful in setting
th e mixture, with
the advantage that the thermocouple is small and can be left in place and you
ca
n keep your eye
on it while racing. Presumably somewhere there is a good correlation chart from
temps to
mixture strength to help me get it right.
Your thoughts, agreements and denials, gentlemen please.
(By the way, these are or course vintage oxygen sensors and vintage exhaust gas
t emperature
thermocouples I am referring to ;-).
--
Malcolm Cox, Napa, CA malcox@napanet.net
Vintage Race MGA 1960, #80
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