62 Classic Car Mart Spring 2016
Both the injection engines featured enlarged
porting and bigger valves.
The B18 and B20 also appeared in the Volvo
140 series, with the D-Jetronic injection replaced
by the simper analogue K-Jetronic system for the
final year of production in 1974.
The engine was destined to disappear from
passenger car production with the launch of
the 140’s successor the 240 but the B20 did
make an appearance in very early production
240s before being replaced by the overhead-
cam B19 design.
Meanwhile, the engine lasted until 1981 in the
Volvo military truck known as C202 in its military
form but more commonly by its ‘Laplander’
nickname. Really not a bad innings for a design
which had first fired in 1944.
STRENGTHS AND WEAKNESSES
Oil changes are needed every 3000 miles,
with spark plugs and air filters being replaced
at 12,500-mile intervals. British specification
engines were specified to run on 10W/30 or
10W/40 mineral oil in period, but many owners
prefer classic 20W/50 as engines age and
tolerances widen. It’s always worth buying
genuine Volvo oil filters, too – they’re fitted with a
relief valve which maintains oil pressure from the
moment you turn the key.
The breather gauzes are also worth cleaning
at each service – there are two of them. One is
located in the filler cap, the other in a cam-
shaped housing on the right-hand side of the
engine block. These can easily clog up and
contribute to heavy engine breathing.
The basic 121 models used a single Zenith
36VN or Stromberg CD175 carburettor. 122S
and 123GT variants breathed through a pair of
SU HS6s. Rebuild kits and new linkage parts
are available for all, although in the case of
the former it’s worth retaining the original jets
and float valves as parts within Zenith overhaul
packs can vary. 36VN-carburetted cars also
use an all-in-one air cleaner with the element
sealed in – the entire unit should be thrown
away at each service. Other models have
replaceable filters.
Balancing the twin SUs can prove difficult, but
the clubs will have technically-minded members
in your area who can help.
Using an Amazon every day throws up a few
common problems which various specialists
have tackled. One such issue is the rear crank oil
seal. The factory specified felt from new, which
deteriorates in time leading to oil contamination
of the clutch. The solution is to fit a neoprene
seal into the housing. It’s a specialist job,
with Amazon Cars and Brookhouse offering
reconditioned seals on an exchange basis – send
your old part in and a surcharge is refunded on
its replacement.
Weaknesses in the timing gear can also show
up on older engines – the original fibre teeth can
break up in use. These can be supplanted with
alloy items although they are noisier in use. CCM The B18 and B20 versions saw service in the 140-series cars.