As some of you may know,my recently completed Vitesse/Sports Six Convertible
is fitted with a warmed over engine,beautifully built,and triple dual-choke
Weber 40DCOE-18 Carburettors,I have now driven the car for a total of 1713
miles from new,I've solved the usual shakedown problems,eg.wrong type of fuel
pumps,S.U.'s now replaced by Facet Silver-tops,and meltdown of Triumph Stag
Fuse box,thanks Joe Lucas,caused by overheating glass fuses,replaced by
Bosch/Hella Fuse box with Ceramic Fuses,problem solved.
However,the car has become increasingly difficult to start from cold only,and
isn't running anything like as smoothly or as powerfully as it should.The 17
mpg fuel consumption is certainly no joke either,remember if you will that
British gallons are 10% bigger than US gallons,(yes we do have something
bigger!),the price of fuel here is more than three times that in the US at
present,(green taxes,you know)...
The problem has been tracked down to a combination of the Moss Motors
three-part ally inlet manifolds,(the sloping ones designed for GT6's with
sloping bonnets/hoods,because the straight TWM manifolds don't fit under the
Vitesse bonnet),these three inlet manifolds have three pedastals supporting a
brass bar,(not tube),running directly in the aluminium casting,the three
weber carbs are linked together by three thin metal brackets,which clamp onto
the brass bar with a bolt,washer and thin nyloc nut.these have gradually
loosened,and have rotated on the brass bar at different rates,thus throwing
the carbs well out of balance.
The Carbs themselves have no visible means of support,apart from where they
are bolted on to the inlet manifolds,(not a clever arrangement),because even
bolted as tight as practicable/recommended the carbs are moving up & down a
little,the front one more than the other two,allowing frothing to take
place.The carbs themselves are attached to the inlet manifolds by studs,thick
rubber button washers/metal cups,and nyloc nuts,this arrangement is thought
to be inferior to the 'double-spring' thackeray washers,also the throttle
linkage itself is a twin-magard affair with ordinary cables,(the nylon lined
cables melted after they were wrongly positioned over the hot headers!).(not
by me).
What I propose to do next is to remove carbs & inlet manifolds,have the
pedastals machined to take needle-roller bearings and a chromed & hardened
copper tube,replace the thin steel carb linkages with ally TWM link-arms,use
thackeray spring washers instead of the rubber button washers/metal cups,make
up rubber mounted support brackets between the outer end of the carbs &
engine block,and replace the rather clumsy & stiff throttle mechanism with
something a little simpler & more elegant from the USA,another pair of
nylon-lined cables and see if that doesn't improve matters somewhat?
To enable me to keep my Triumph on the road,while that lot is being
machined,I'm fitting an inlet manifold & a pair of 1.5" SU's being lent to me
by a local Triumph club member for the duration of the work.
If any of you fine guys & gals out there have any ideas/experience in dealing
with any of the above sidedraught Weber Carb linkages etc,I should be
exceedingly gratified to hear your thoughts/suggestions etc.
Now,I'm off to the TR Register International Rally at Shepton Mallet,in the
west of England,Weber Carb problems or not!
ps.I actually met Johnny Storm,International Race Car Driver at the TSSC
International last weekend,and told him how much all you fellow listers were
missing him! (I think).
Kind Regards
Leon F Guyot
TSSC International Liaison Secretary
|