The Bentley Mark 6
and its brothers (or sisters if you prefer)

 

ROLLS-ROYCE'S new postwar "rationalised" production was based one chassis.

When Rolls-Royce shut down car manufacture for war production in the late 1930s they were producing what amounted to three different cars with little in common. This was unsustainable even then, and impossible after the War. Their postwar production was to be based on one chassis design.

The smallest version of this was the Bentley Mk 6, introduced in 1946. It was the first car to emerge from the factory complete with a standard pressed steel body, and although it was intended there should be a Rolls-Royce version at the same time, the Company was so nervous about having a "mass-produced" Rolls-Royce that they postponed its introduction.

The Rolls-Royce model available beside the Bentley was the Silver Wraith. This consisted of the same basic chassis, engine and transmission as the Bentley Mk 6, but intended for the coachbuilding trade. It had a wider track (achieved, according to rumour, by lengthening the front wishbones rather than widening the chassis rails), and a longer wheelbase. In fact, two longer wheelbases.

As we know, the Mk 6 was a commercial success, so the Rolls-Royce version, the Silver Dawn, appeared in 1949 and it too was a success. The Dawn used the same standard steel body from the scuttle back, but all the front sheet metal was different to accomodate the square radiator. The engine had one carburettor instead of two, and a bench seat was used instead of the two bucket front seats in the sportier Bentley.

The biggest and most radical expansion of the basic Mk 6 was the enormous Royal Phantom 4. This started with the longest wheelbase Silver Wraith chassis, and was lengthened still further. The all-up weight was so vast that even the gutsy 4.6 litre six just wasn't strong enough, so Rolls-Royce modified the straight 8 military engine (technically the same as the six), and at 5.7 litres it was sufficient for the job, having masses of torque.

Just think about it:
Wheelbases, for example:

Bentley Mark 6/Rolls-Royce Silver Dawn: 120 inches
Rolls-Royce Silver Wraith: 127 inches or 133 inches (a 7 inch or a 13 inch stretch)
Rolls-Royce Phantom 4: 145 inches (a 25 inch stretch).

And here are examples: A Mk 6, a Silver Wraith, and the Phantom 4 once owned by Princess Margaret. Hard to believe they are all the same basic design! (The Phantom 4 does looks like a huge Mk 6: compare the lines!)