The
Commander / President Straight Eight:
1929 – 1930: The Commander Straight Eight engine was a
completely new engine design, patterned after it's big brother the
President Eight. It was released in the Model FD Commander. It had
a bore of 3 1/16 inch and a stroke of 4 1/4 inch (250.4 cubic
inches), making 80 HP. It had one refinement, yet to reach it's
sibling, the President, it was designed with nine main bearings.
Revisions:
1931, (Model 70 Commander): valve spring dampeners,
carburetor silencer, new carburetor, dual intake manifold, and
improved torsional vibration dampener. Horsepower increased to 101.
1932, (Model 71 Commander): no changes to the engine
design.
1933, (Model 82 President): in 1933, no Dictator Eight
was manufactured, therefore, the Commander Eight used the Dictator
engine, except bored out to 4 inches. This freed up the existing
Commander Eight engine ( 3 1/16 x 4 ¼ – 205.4 cubic inches – 110
HP) for use on the Model 82 President.
1934, (Model C President): no engine changes.
1935, (Model 1C President): no engine changes.
1935, (Model 1B Commander): this engine is used for the
last time on the Commander, with a cast iron head and compression
ratio of 6.0 to 1, making 107 HP.
1936, (Model 2C President): compression ratio increased
to 6.5 to 1, Horsepower increased to 115.
1937, (Model 3C President): no engine changes.
1938, (Model 4C President): compression ratio decreased
to 6.0 to 1, Horsepower decreased to 110. The water pump was moved to
the front of the engine, driven off the fan pulley.
1939, (Model 5C President): no engine changes.
1940, (Model 6C President): no engine changes.
1941, (Model 7C President): compression ratio increased
to 6.5 to 1, Horsepower increased to 117.
1942, (Model 8C President): no engine changes.
After
1942, the Commander / President Straight Eight would never again be
manufactured.
The
Dictator Straight Eight:
1930, (Model FC Dictator): the Dictator Straight Eight
engine was a completely new engine design, patterned after the
Commander Eight, but with a shorter stroke. It had a bore of 3 1/16
inch and a stroke of 3 ¾ inch (221 cubic inches), making 70 HP.
Revisions:
1931, (Model 61 Dictator): improvements in manifolding,
and the carburetor, result in 81 HP.
1932, (Model 62 Dictator): horsepower increases to 85.
1933, (Model 73 Commander): as there were no Dictator
models manufactured in 1933, the Dictator engine became available for
the Commander, which had lost it's Commander engine to the President
line. The stroke was increased to 4 inches (236 cubic inches),
making 100 HP.
1934, (Model B Commander): the dimensions and
displacement, reverts back to the original Dictator engine (3 1/16
inch bore and stroke of 3 ¾ inch - 221 cubic inches). Horsepower
is raised to 103 by increasing the compression ratio to 6.3 to 1 and
using an aluminum cylinder head.
1934
would be the last time the Dictator Straight Eight engine would be
manufactured.
Credit: The information source for this article came from "Studebaker The Complete Story" by William Cannon and Fred Fox.