Buick straight-8 engine

The Buick straight-8 engine (Fireball 8) was a straight-eight cylinder automobile engine produced from 1931 to 1953 by the Buick division of General Motors. It replaced the Buick Straight-6 engine across the board in all models on its debut.

Design

Unlike most other car makers at the time, Buick had been using a valve-in-head/OHV overhead valve reverse-flow cylinder head design or I-head since their inception and continued this practice in their straight-eight designs. The engine was sold in different displacements depending on the model of car and the year and was constructed upon two distinct (possibly more) block castings. The engine block in the smaller displacement versions internally resembled the 1937-53 inline Chevrolet 216, 235 & 261" straight six (the combustion chamber design was quite different), albeit with additional cylinders. The large block version (320 cid and 345 cid; used in large-chassis models such as the Roadmaster) was considerably heavier and this weight adversely affected vehicle performance and handling. In earlier years the engines used cast-in-place bearings that were then machined, which made engine rebuilding an expensive procedure, but after 1937 they began using drop-in bearings.

Initial compression ratio varied between 4.5:1 and 4.75:1 in different engines, with Template:Cvt, Template:Cvt and Template:Cvt for 221, 273 and 345 engines respectively; when the 320 engine was introduced, it produced Template:Cvt, increasing to Template:Cvt later.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

The last year for Buick's straight-eight was 1953, but only in the lower-cost Buick Special. All other lines using the same basic chassis received the new [[Buick V8 engine#322|V8 Template:Cvt Fireball]]. Starting in 1954, the Special received the V8 as well.

Production	Engine	Displacement	Bore x Stroke
1931	221	Template:Cvt	Template:Cvt
1931–1933	273	Template:Cvt	Template:Cvt
1931–1935	345	Template:Cvt	Template:Cvt
1932–1933	230	Template:Cvt	Template:Cvt
1934–1935	235	Template:Cvt	Template:Cvt
1934–1935	278	Template:Cvt	Template:Cvt
1934–1936	233	Template:Cvt	Template:Cvt
1936–1952	320	Template:Cvt	Template:Cvt
1937–1950	248	Template:Cvt	Template:Cvt
1950–1953	263	Template:Cvt	Template:Cvt
source: Carnut.com<ref>{{#invoke:citation/CS1|citation				CitationClass=web }}</ref>

File:1939 Buick Dynaflash inline-eight in a Series 40 Special.jpg

1939 iteration ("Dynaflash") in a Series 40 Special, Template:Cvt

1952 Production Engines and Ratings

Series	Engine	Displacement	Bore x Stroke	Power
40	263	Template:Cvt	Template:Cvt	Template:Cvt at 3600 rpm
50				Template:Cvt at 3600 rpm
70	320	Template:Cvt	Template:Cvt	Template:Cvt at 3800 rpm
Note: The 320 has a head length of 34 Template:Frac" while the smaller engines are 31 Template:Frac" long.
source: 1952 Buick service manual<ref>{{#invoke:citation/CS1|citation					CitationClass=web }}</ref>

See also

• Buick V8 engine
• Buick V6 engine
• Buick Straight-6 engine
• List of GM engines

References

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