327 Chevy Engine: Unveiling Untapped Potential

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There is no question that Chevy knew how to make a small block V8 in the day. But one of the best was the 5.4L 327 V8, dubbed the “Mighty Mouse.”

During its eight-year run, the 5.4L (327) V8 is a small block built by Chevrolet from 1962 - ‘69. It was nicknamed the “mighty mouse” due to its power and compact size. The horsepower was 360 hp with 352 lb-ft of torque. The engine was used in various models as the base V8 and optional V8 motor.

While most people envision the Corvette as a powerful beast, ready to take on all comers, the sports car had humble beginnings. While the initial buzz for the concept car was brisk, sales of the early models didn’t take off. A large part of the issue was the car's lack of power under the hood. The first Corvettes were powered by an inline six and had no more power than a normal sedan. GM knew they needed a more powerful performance engine to convince buyers to purchase their car. So, they got to work. Their efforts resulted in a small-block V8 (265 ci) that generated more horses but wasn’t quite strong enough. Chevy continued to tinker with their car for the next few years, and they finally settled on the 327 V8 as the powerhouse the Corvette deserved. This scrappy little V8 would be Chevy’s longest-produced small-block, perhaps its best. The “Mighty Mouse” would save the day and put Chevrolet on the map so the Corvette could take on all comers. The company liked the motor so well that it made countless versions and situated the V8 in almost every model it manufactured. Let’s look at this great V8 engine and see if it did live up to its reputation.

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When Was The 327 V8 First Developed?

The 327 V8 was released in 1962 as an update to the 283. Chevy had enjoyed success offering the previous 283 V8 in various vehicles, so it did not want to limit the new engine to just the Corvette. For 1962, the “new” 327 V8 was offered in the Corvette, Impala, Biscayne, and Bel Air. The Corvette also had a new engine, which meant thrilling new power for customers.

Chevy offered different options for the small block during the first few years, with differing power outputs and compressions based on the carburation installed. (Single 4 bbl or fuel injection). The 1962 sales brochure offered Corvette customers four different 327 ci V8s. The three single 4 bbl carburetor models had power ranging from 250 hp as the standard V8 (L30) to 300 hp (L74/75) or a 340 hp version. (While both used large aluminum carbs and modified intake manifolds, the 340 had a Duntov cam system with mechanical valve lifters). The ultimate peak performer was the 327 V8 that shelled out 360 hp (L84) with the Ramjet fuel injection system. Full-sized Chevy’s had to settle for just two versions of the 327; the 250 hp TurboFire V8 (L30) with a single 4bb carb and the 350 hp TurboFire V8 () with a four-bbl carburetor. (In fairness, Chevy offered two 409 Big Block V8s to compensate for it).

Over the next few years, Chevy continued to tinker with the 327 V8. In 1964, the horsepower was boosted again as Chevy released the L76, and the fuel injected L-84 but dropped both motors the next year when it brought out the legendary L-79, which was a modified L-76. In 1967, the company released a 2 bbl carburated version of the 327 V8 (LF-7), which they used in various models, including pickup trucks. The Corvette offered two choices of the 327 v8 that year, the L74/75 and the L79, but also tempted owners with new 427 ci small block V8s (L71).

In 1967, GM dropped the compression of the 327 V8 to a pitiful 8.5:1, severely affecting the power output (210 hp and 320 ft-lb of torque). It was clear that GM was spending its time and attention on the 350 V8, which Chevy had slapped into the new Camaro.

The 327 V8 was used by Checker for a couple of years in ‘68 - ‘69 to produce their A12 and A12w taxicabs. In addition, GM sent the engine to Gordon-Keeble, who used it in 99 of their vehicles. The 327 V8 was used by the Italian manufacturer ISO Rivolta until 1972. Holden of Australia used the small block V8 in their Monaro GTS327, which succeeded on the track as a race car.

By the time 1969 rolled around, Chevy started to quietly phase out the 327 V8 in favor of the 350 ci. The new 5.7L V8 (350) became the standard engine for the Corvette (L46), and the (L48) became the engine for the Camaro and Nova for a couple of years.

What Are The Features Of The 327 V8 Engine?

The 327 Chevy engine shared cast iron blocks and cylinder heads with a modified bore size of 4.0 inches (slightly larger than the 283 V8). The stroke is 3.25 inches. The 327 Chevy engine is bored and stroked out of the 283. The intake manifold was made in both cast iron and aluminum.

The carburetors were varied, as the lower powered Chevy 327s were installed with Carter AFB 4bbl, while higher output engines had a larger four-barrel Holley carburetor. The Ramjet fuel injection system was available on the highest-performing engine for the Corvette only until GM ceased production in mid-1965. While the RamJet system had made its debut in the fifties, the mechanics had been refined by the time the new Ramjet system appeared with the 327 V8. The mechanical injection system used vacuum pressure to dispense the appropriate fuel as the engine demanded. Clearly, the Ramjet significantly boosted power, and more power meant faster speeds, but the system was sometimes unstable. It was also much more expensive for Chevy to produce. The increased production costs forced Chevy to abandon the inconsistent fuel injection system for carburetor-mounted sports cars.

The compression ratios varied depending on which 327 engine you had. The base (L30 and L74/75) had a 10.5:1 ratio, while the L79 version was clocked at 11.0:1, and the 360 hp version bumped the compression to 11.25:1.

What Are The Specs Of The 5.4L (327) V8?

Why Did Chevy Stop Making The 327 V8?

When Chevy introduced its new Camaro with a more powerful 350 V8, the handwriting was on the wall for the small block engine. Chevy offered the new Camaro with a 210 Hp 327 V8 or 275 hp 327 V8 (25k units sold) and a 350 with 295 hp (29k Camaros sold).  Despite the new engine, most customers were not too impressed with the new V8, since the upper 327 V8 had as much power as the new motor.

What Were The Issues With the 327 V8?

There are very few issues that have been reported with the 327 V8. Considered to be extremely reliable and dependable engines that Chevy ever built, owners were very pleased with the motor's longevity.

One of the best things about the 327 is that they were easy to work on, and the parts could quickly be swapped with other motors. Many hotrodders and classic car enthusiasts used the Chevy small block and tweaked the motor to produce even more horsepower.

Is The 327 V8 A Reliable Engine?

History is always the best judge of a manufacturer’s work quality. Since the 327 V8 hasn’t had many issues, and was the preferred motor for many early drag racers or hotrodders, we would say that it is pretty reliable. If the engine had an issue, owners would have lit up the Internet about it, but there is scarcely a peep. Obviously, any engine has to be maintained to perform well.

Do They Still Make The 327 V8 As A Crate Engine?

Although GM no longer makes the 327 V8, it is possible to purchase a 327 V8 from an aftermarket purveyor. Many companies or Corvette specialty houses still carry the engine as a crate motor.

How Can I Tell If My Engine is A 327?

General Motors usually stamped their engines with an ID plate on the passenger side of the cylinder head just behind the alternator.