And one
published in the Jaguar Driver for April 1995
Startling
Discovery
JUST BEFORE GOING to press for this April edition,
SS Jaguar Historian Reg D.
Bates sent me details of a sensational project that SS cars were
working on in 1938,
and which he has just unearthed after years of patient probing. I'm
sure you will
agree with me when I say that, if only the factory had had more time
and money at
their disposal, this car could have turned out to be the greatest Grand
Tourer of the
1930s, and might have altered the whole of Jaguar's post-war
engineering direc-
tion. Reg apologises for the quality of the photo, but it almost turned
back into dust
as he handled it, and even with modern reproduction equipment that was
the best
he could manage. I will let Reg tell the whole story...
The SS Jaguar Straight Eight Coupe by Reg D. Bates
MUCH HAS BEEN written about the SS Jaguar 100 coupe that caused such a
sen-
sation at the 1938 Motor Show, but few are aware that this was only a
last minute
substitution for the real SS Jaguar Coupe. The real coupe was based on
the SS saloon
chassis and was fitted with a straight eight 3.5 litre engine. So far
as I know very little
evidence remains of this extravagant folly but with the recent
discovery of a section-
al drawing of the engine and what is believed to be the only surviving
photo
taken outside the Holbrook Lane works, now seems a good time to revisit
it.
It is well known that the 3.5 litre engine was developed from both
boring and
stroking the 2.5 but few people know that this engine was built as an
emergency
measure because of the development problems with the straight eight.
Retain-
ing the same cylinder dimensions as the 1.5 and 2.5 litre engines the
straight eight
was created by further lengthening the castings. Pistons, con rods,
bearings and
much of the valve gear was taken directly from the parts bins of the
smaller engines.
The result was an engine of 3552 cc which was claimed to produce a
power output of
140 bhp at 4500 rpm and have a maximum torque of 180 ft. Ibs at 2200
rpm.
The target vehicle for the eight was the SS Jaguar Coupe. The Coupe
shared the
same overall dimensions as the 2.5 litre saloon but was built on a
modified chas-
sis in which the gearbox crossmember was 8 inches further back.
Unfortunately
this relatively small change when compounded with the increased loading
resulting from the heavier engine block proved to be the downfall of
the design.
The front chassis members tended to act like a giant tuning fork which
was set
into oscillation by road shocks transmitted through the front springs.
By the time
of the Motor Show the car was in no fit state for display to a press
and public
keen to try out a dramatic newcomer.
It is said that on the eve of the show 1938 Motor Show it was well known
within the company that all was not well and that William Lyons himself
demand-
ed that the car be diverted from Earl's Court to Brooklands where he
carried out
the first true test drive on it. The occasion was marked by extreme
secrecy but after
a high speed lap of the notoriously bumpy track, Lyons apparently was
incredulous at the behaviour of the car. Those who were present had
expected the
somewhat shaken Lyons to vent his anger upon them but in the event
nothing fur-
ther was said except that the car would not be appearing at the show.
Thereafter further development work was continued with some small
improve-
ment being effected by a doubling in the size of the weights at the ends of the
harmonic
stabilising front bumper, but after failing to eliminate the
oscillations using two front bumpers
the project was abandoned. Early in April 1939 the only prototype was
buried close to the
works in a land fill site along with other debris in what eye witnesses
described as an event
marked by a sense of unreality.
Some say that the double bumpers of the Mark V were fitted purely as a
reminder of the
incredible problems encountered in the Coupe and that this unfortunate
memory has prevented
any further attempts with long straight eight engines. Others blame it
on the unlucky out of
sequence chassis number: 010495.