COMPARISONS - a dissection of a 1923 Model.
Much is made of the great interchangeability of components
within the various models of
Austin Sevens. But many parts, although they may be capable
of being swapped around,
are quite different when it comes to making your car "as
original". If we take say a mid-
1923 model compared to a 1927 model, here are just a few of
the differences in the
Starting at the front, the
two piece, the handle cottered to the shaft,
whereas the '27 handle is one piece.
Crankcase & Block
- the early crankcases are quickly recognizable by the
symbol being cast in a different place on the outside. The
block had gone to the 56mm
bore, but the tappet
plungers for a while continued to be of the
quite different from the familiar straight-sided plungers.
Obviously the brass tappet
guides were a different shape to suit. The gudgeon pins
altered and early on the cylinder heads were fitted with priming cocks.
Timing gear cover
- Because the
camshaft on the earlier car had no locating shoulder
for the front bushing, it was necessary to adjust
end float from the exterior - and
provision for this is located on the front of the cover.
- the familiar flat meshed frame did not appear in the
Instead, a dished sheet-metal plate had three wells along
its length, each well having a
solid bottom but meshed sides.
These early cars had
no speedometer, no fan, for a while
no choke flap on the
carburetter, no starter motor
(the clutch chamber had a two-piece cover on its top), the
had no chamfer (no need for ring-gear clearance before
starter motors were
fitted), the gearbox
filler was located on the front of the top cover (once
were fitted they covered the filler hole so it was necessary
to relocate & recast towards
the rear of the lid).
had the outlet tap located directly over the exhaust pipe,
so this tap was
moved on later models. The early tanks had no mounting lugs
at the rear, the tank being
located by its rear sitting on the instrument board lip and
fastened to it by a long brass
strap which ran over the top rear and down each side.
The rear of the gearbox
did not have the familiar flexible disc, but a Hookes joint
end of the output shaft. This was located to a Hookes joint
on the end of the
tail shaft by
a slotted ball acting as a universal joint and enclosed by a
two-piece brass housing.
featured in the early days, from a
housing, to the
instrument panel with ammeter,
aluminium-covered cut-out, to
head and tail
The horn button
was located on the instrument panel, not the steering wheel,
itself was a small
Benjamin, not a large Rist and the
to a BLIC.
The chassis rails
had no upturn lip on the top-hat flanges, had
no brackets for shock
absorbers at the rear,
had a simpler
nose-piece casting with again no provision for
had only two holes to attach the
instead of the triangular riveted backing plate on the
front radius-arm ball mounting, it
just had the ball backed by a threaded stud which went
through the cross member & was
held by a washer and nut. The
front cross member
had no inboard supporting brackets
for the floor.
The front axle
had no bosses or holes to mount a damper, had
no tin dust shields,
no casting for grease nipples
at the kingpins - instead it had a fitting with a
to lubricate the
swivel pins. The important difference was
the stub axles
so that tapered bore wheel
bearings were necessary.
no dust shields,
had tapered bore bearings,
also the c w& p
housing had strengthening
flutes running from the central drum to the axle trousers -
three each side.
front and rear had 6"
brake drums. Over the years Austin Seven
brake levers lengthened, but the '23 ones are even
shorter than the short 1927 levers!
In summary, it's more a matter of what was
not there as much
as what was different or