On this day in engineering history, the last American-built
Rolls-Royce Phantom I was delivered to the home of Mrs. M.S. Morrow of Whitestone, New
York. Manufactured at the Rolls-Royce plant in Springfield, Massachusetts,
the Phantom had replaced the Silver Ghost, a 6-cylinder vehicle whose
popularity had prompted the British-based company to open a second American
factory in Springfield in 1921. Ultimately, over 1500 "Springfield Ghosts" graced the roadways
of the United States.
Some Phantom I vehicles (as shown in the picture at left) are still in working condition today.
Pushrod Engine
Unlike its predecessor, the Rolls-Royce Phantom I featured a
new pushrod, straight-6 (L6) engine that used aluminum instead of iron in its
cylinder heads. Sometimes called an overhead valve (OHV) engine or I-head
engine, a pushrod engine places the camshaft in the cylinder block. Rods or
pushrods then actuate the rocker arms above the cylinder heads. In turn, this
actuates the valves. The lifters or tappets, parts of the rocker arms that make
contact with the valve-stems above the cylinder heads, transfer sideways force
and impart linear motion. Tappets fail or break over time, however, and pushrods
can flex or snap at high engine speeds.
Both Sides of the Pond
The 7668-cc engine in the Rolls-Royce Phantom I is also
notable in that it produced relatively large amounts of power for its automotive
era. Equipped with a 4.25-in. bore and 5.5-in. stroke for a total of 7.7 L of
displacement, the pushrod engine was designed to move a heavy car along
primitive roads. During the 1920s and 1930s, Rolls-Royce built a total of 1,241
Phantom I's at its factory in Springfield,
Massachusetts. A larger number of
vehicles (3.500+) were built at the Rolls-Royce factory in Derby, England.
Three-Speed and Four-Speed Transmissions
Unlike their American counterparts, the British-built
vehicles featured a manual, four-speed transmission instead of a three-speed
design. Both the British-built and American-made vehicles were considered to be
luxury cars, however, as their elegant design still suggests.
Resources:
http://www.history.com/this-day-in-history.do?action=Article&id=7577
http://en.wikipedia.org/wiki/Rolls-Royce_Phantom_I
http://en.wikipedia.org/wiki/Rolls-Royce_Limited
http://en.wikipedia.org/wiki/Pushrod_engine
http://en.wikipedia.org/wiki/Tappet
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