Page 15 - Bentley Mark VI & R-Type

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ON WATSON FINE BO
MASCOTS
The earliest Bentley Mark VI cars were fitted with a rearward-leaning
Winged-’B’ mascot of a type first used in the late 1930s, using up stocks left
position when the bonnet was opened.
also had no mascot.
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over from pre-war production that once used up, gave way to the forward-
leaning pattern that served on Bentley cars for more than three decades.
The rearward-leaning Winged-’B’ was required to be turned 90 degrees
before opening the bonnet to avoid the bonnet fouling the mascot wing-
tips, whereas the later forward-leaning mascot could be left in its normal
Some Bentley Continentals lacked the dummy water filler cap and thus
The Silver Dawn was fitted with the ‘kneeling’ type Spirit of Ecstasy mascot
which, like the original 1911 mascot, was designed by celebrated artist and
sculptor Charles Sykes and introduced in 1934. This mascot was chromium-
plated and did not need to be turned before opening the bonnet.
CYLINDER LINERS
This is an instance in which Rolls-Royce Ltd’s legendary engineering
expertise appears to have twice faltered. In the earliest post-war engines
Rolls-Royce adopted its successful war-time aero engine practice of
‘flash-chroming’ the upper bores, with the intention that bore wear –
which mostly occurs in the upper part – would thus be minimised. The
avowed intention was that the post-war engines should have a life of at
© DALTON WATSON FINE BOOKS
least 100,000 miles before requiring a major overhaul. However, it quickly
became clear that ‘flash-chroming’, which consisted of a 15 thousandths
of an inch deposit of chromium on the upper 2¼-inches of the cylinders,
had produced mixed results when applied to motor car engines, and
from chassis B144DA short pressed-in high chromium content liners were
substituted. Many of the earlier engines were modified.
Although it was prematurely claimed that the short liners met “with
complete success”, unfortunately the passage of time has shown that after
high mileages they resulted in a ‘step’ forming in the bore due to the iron
below the liner wearing at a greater rate than the liner itself. The result was
broken rings and high oil consumption. The only reasonable solution, first
introduced on the Bentley Continental ‘D’ and ‘E’ series fitted with the
4,887 c.c. engine, was to adopt full-length liners, and many, if not most of
the earlier engines of 4,257 and 4,566 c.c. still in service have been so fitted.
LUBRICATION
At its introduction the Mark VI was equipped with a ‘by-pass’ engine oil
filtration scheme in which a proportion of the circulating oil was diverted
fitted with full-flow filtration.
Further Chassis & Coachwork Development © DALTON WATSON FINE BOO
through the filter. From the ‘M’ series – the first cars with the 4,566 c.c.
engine – a change was made to a full-flow system in which, as the name
suggests, all of the circulating oil passed through the filter on every pass.
The Silver Dawn followed suit from the start of the ‘C’ series.
Many earlier cars built with the by-pass system have been retrospectively
All models dealt with in this book were equipped with a centralised
chassis lubrication system which consisted of a system of small-bore brass
tubes carrying oil from a Girling-Bijur reservoir and pump operated by a
pedal under the fascia to various points of the steering and suspension.
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