Owners Manual
AUSTIN
A40
SERVICE
MANUAL
D/1
ENGINE
DURING
the early
part
of
its life the working parts
of
an
engine settle down with
the
result
that
various
clearances
and
adjustments need to be corrected. Thereafter, to obtain maximum efficiency, the engine should
be treated with due respect
and
afforded its regular maintenance
at
the prescribed intervals.
GENERAL DATA
Crankshaft and Bearings
Crankpins
and
Big End
Gudgeon
Pin
to Piston
Camshaft and Bearings
.
000£
to
. 002-in. (. 01905 to . 0508-mm.)
.000!
to .001!-in. (.0063 to .0381-mm.)
. . .
Thumb
Fit
at
70°F. (21. 1
oc.)
.
001
to . 002-in. (. 0254 to . 0508-mm.)
. 002 to . 008-in. (. 0508
to
. 2032-mm.)
. 002
to
. 003-in. (. 0508 to . 0762-mm.)
Camshaft
End
Clearance or Float
Crankshaft
End
Clearance
or
Float
Thrust
...
Side Clearance Connecting
Rod
and
Crankshaft
Crankshaft Diameter
of
Journals
Diameter
of
Crankpins
Valve Tappet Clearance
Piston
Fit
Piston Ring
Gap
Taken
by
thrust washers on centre main bearings.
.008t
to .Ol2t-in. (.2159 to .3175-mm.)
1.8749 to 1.8754-in. (4.7621
to
4.7634-cm.)
1.
7499
to 1. 7504-in. (4.4446 to 4.4591-cm.)
.015-in. (. 381-mm.)
.015-in. (.381-mm.)
at
top land: .0012-in. (.0304-mm.)
at
skirt.
.
008
to . 012-in. (. 2032 to . 3048-mm.)
Undersized bearings
of
.020-in. (.508-mm.) and .040-in. (1.016-mm.) are listed.
The
crankshaft regrinding sizes
for undersize bearings are tabulated below.
Regrinding
Sizes
Undersize
of
Crankpins Journals
Bearing
Minimum
Maximum Minimum
Maximum
.020-in. (.508-mm.)
1.
7299-in. ( 4;3938-cm.)
1.7304-in. (4.3951-cm.) 1.8549-in. (4.7113-cm.) 1.8554-in. (4.7126-cm.)
.040-in. (1.016-mm.)
1.
7099-in. (
4.
3440-cm.)
1.7104-in.
(4.3443-cm.) 1.8349-in. ( 4.6605-cm.) 1.8354-in. (4.6618-cm).
Cylinders and Crankcase
The
cylinders are
of
the
cast
iron
monobloc type
with the crankcase being
an
integral
part
of
the block.
The
cylinder bore diameter is 2. 578-in. (6. 5479 em.).
The maximum permissible reb ore
is
the diameter + l
6
-in.
(1. 5875
111111.).
Cylinder
Head
The
head is
of
cast
iron
construction
and
is
secured
to the block by eleven
i-in.
(15. 875 mm.) high tensile
steel studs. Between the cylinder
head
and
cylinder
block is fitted a copper armoured
hard
clay
board
washer which has a compressed thickness
of
. 053-in.
(I.
3462 mm.). Torque wrench loading for
cylinder head
nuts-40
lbs. ft. (5.
53
kgm.).
Crankshaft
The counter-balanced crankshaft is
of
forged steel
and
has three main bearing journals.
Main Bearings
Each
of
the three
main
bearing shells are
of
steel
construction and are fitted with linings
of
white metal.
The crankcase walls are recessed
to
locate each end
bearing cap, whilst the centre main bearing has a thrust
washer
at
each side to take end thrust.