[v12-engine] Correct running temp and timing

Hi, all…

I know this topic has been beat to death, and I’ve searched
the archives for relevant info but haven’t found what I’m
looking for. Also have Kirby Palm’s book about V12’s but
that deals mostly with the XJ’s.

Also, the owner’s manual and the factory workshop manual for
my SIII Coupe say different things about how to set the
timing. Complicating things further, I do not have the
original ignition system in the car, instead having upgraded
to the XJ ignition system. I completely disassembled the
distributor and rebuilt it a couple years back. Then the
car was stolen and it has been sitting until I got the time
to rebuild the carbs and spend some time on the car. Now
it’s running again and I’m trying to line it out so I can
drive it regularly.

Bottom line, I’m trying to determine a ‘safe’ temp for the
car to be running. I have set the timing at 12 degrees BTDC
at idle. I’m taking vacuum from the driver’s rear carb. I
need to investigate this further because I have no vacuum at
idle, only the slightest blip of vac when the foot goes on
the gas. What I can say for sure is that I appear to have
about 30 degrees BTDC at maybe 2500RPM. I’m unsure about
exact numbers on the engine speed because the tach isn’t
working after the ignition changeover (subject for another
post/query). Last night I used a digital meat thermometer
in the header tank as the car warmed up. I found that I go
from about 90 degrees as the temp gauge comes off the peg,
140 at the ‘N’, 155 at the ‘R’, and approx. 180 at the ‘L’.
As I drive it, the car wants to run with the needle one
needle width to the right of the ‘L’, meaning about 190 or
so, although it never seems to push much past this point.
This seems very warm compared to where I remember the car
running before all the reworking. I definitely recall it
running closer to the ‘R’ when out on the road in past days.
The fans do come on and cycle somewhere just past the ‘L’,
and appear to pull plenty of air thru the radiator.

Do I have a problem? Last thing I want is to get
comfortable with this and end up with a big issue with the

Thanks for any guidance or experience with this.–
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !