Editing Buick V8 engine (section)

==Second-generation Nailhead==
Buick's second variation of the "Nailhead" was produced from 1957–1966. The "Fireball" name was dropped after 1957, but the 364 was very briefly called the "B-12000", referring to the 12,000 pounds of force generated by each piston.<ref name=Flory>{{cite book|last=Flory Jr.|first=J. "Kelly"|title=American Cars, 1946-1959 Every Model Every Year|year=2008|publisher=McFarland |isbn=978-0-7864-3229-5}}</ref> Second generation Nailheads were painted "Late"{{clarify-inline|date=July 2024}} Buick Green, with the exception of those installed in the 1963 Riviera, which were silver, and the 1966 Riviera, which were red.<ref name=TeamBuickengcol/>

===364===
Buick, like most of its competitors, continued to expand their V8 engine to larger displacements. The {{cvt|364|CID|L|1}} was introduced in 1957 and produced through 1961, with a {{convert|4.125|x|3.4|in|mm}} (bore by stroke). The Special series cars came standard with the {{cvt|250|hp|0}} [[Carburetor#Two-barrel_and_four-barrel_designs|two-barrel]] carburetor version, where all other models got the {{cvt|300|hp|0}} [[Carburetor#Two-barrel_and_four-barrel_designs|four-barrel]] engine. 

==={{anchor|401}}401 (400)===
[[File:1963 Buick 401 Nailhead.jpg|thumb|1963 401 Buick V8]]
The 364 was enlarged to {{cvt|6572|cc|CID L cc|1|adj=ri0|order=out}} and produced from 1959 to 1966. Bore and stroke were enlarged to {{convert|4.1875|x|3.64|in|mm}} respectively. Originally labelled a 401, it was later redesignated "400" (with no change to displacement) to meet 1960s GM directives for maximum allowable engine displacements in [[mid-size car]]s.

The 401/400 became Buick's [[muscle car]] powerplant of choice, used in the company's [[Buick Gran Sport|Skylark Gran Sport]], [[Buick Sport Wagon#1968–1969|Buick Sport Wagon]] and [[Buick Wildcat]] models, among others.  The engine was variously designated the Wildcat 375, Wildcat 410, and Wildcat 445 depending on the [[torque]] each version produced. The Wildcat 410 was the two-barrel carbureted engine, standard on the 1962-63 [[Buick LeSabre|LeSabre]]. The Wildcat 375 was a no-cost option for the 1962-63 LeSabre that used a lower compression ratio to run on lower-[[octane]] fuel. The various Wildcat engines had decals on their air cleaners indicating their version; however, the four-barrel edition of the 1966-67 small-block Buick 340 V8 was also labeled Wildcat 375 on its air cleaner, but was not a Nailhead.

The Wildcat 445, with a single four-barrel carburetor, was the standard engine in the [[Buick Invicta|Invicta]], 1959-1966 [[Buick Electra|Electra]], 1962–1966 [[Buick Wildcat]], 1963 [[Buick Riviera|Riviera]], and 1965 Riviera (the 1964 and 1966 Riviera models used the 425 with a single four-barrel carburetor, labeled Wildcat 465, as standard equipment).

In an effort to overcome the restrictive exhaust-port design of the Nailhead, Buick [[drag racing]] enthusiasts in the 1960s adapted [[supercharger]]s with a custom camshaft to feed intake air in through the exhaust ports; the larger intake ports became the exhaust outlets.

===425===
[[File:Super Wildcat 425ci 390hp Engine.jpg|thumb|Super Wildcat {{cvt|425|cid|L|1}} {{cvt|390|hp|0}} engine]]
The {{cvt|425|CID|L|1}} was produced from 1963 to 1966. Its bore and stroke measured {{convert|4.3125|x|3.64|in|mm}}. The largest-displacement version of the Nailhead, it began as an option on the 1963 Riviera, and was later available on the Wildcat and Electra models. The 1964 and 1966 Rivieras used the 425 engine as standard equipment. Mounted on a trolley, Buick 425s were also [[Pratt & Whitney J58#Starting|used as starter motors for the SR-71 Blackbird]] supersonic jet.<ref>{{Cite web|url=https://commons.wikimedia.org/wiki/File:AG330_start_cart.JPG|title=English: SR-71 Blackbird AG330 start cart, Hill Aerospace Museum, Utah|date=8 March 2010|access-date=7 June 2023|via=Wikimedia Commons}}</ref><!--Use of [[Buick V8 engine]] family is also supported by Graham 1996.-->

Four-barrel carburetion was standard on the basic 425, called the Wildcat 465 for the torque (as measured in lb-ft) it developed. The Super Wildcat ([[Regular Production Option]] {RPO}-coded Y48) was available on the 1964 Riviera as a factory option (2,122 produced), 1964 Electras (any model, production numbers unknown), 1965 Riviera Gran Sport and 1966 Wildcat GS, which included two four-barrel carburetors and matching [[intake manifold]]. Coded "MW", these parts were delivered in the car's trunk for dealer installation. Toward the end of the 1966 model year, around May 1966, Buick offered the Super Wildcat 465 with factory-installed 
dual four-barrel [[Carter Carburetor|Carter AFB]] [[carburetor]]s as an "MZ" option. Only 179 of the 1966 Riviera GS cars were built with the MZ package.
[[File:Buick400.jpg|alt=1969 Buick Grand Sport 400 Cubic Inch Engine|thumb|1969 Buick Grand Sport 400 Engine]]