jeffquitney
patreon
Chevy 396 / 402 / 427 cu in 390 hp Engines from "Impact '66" (1966) Chevrolet Division, General Motors
🕑 Added 2020-01-09 21:51:34 +0000 UTCmore at http://quickfound.net/
'Announcement film introducing the new 1966 Chevrolet models.'
Originally a public domain film from the Library of Congress Prelinger Archives, slightly cropped to remove uneven edges, with the aspect ratio corrected, and one-pass brightness-contrast-color correction & mild video noise reduction applied.
The soundtrack was also processed with volume normalization, noise reduction, clipping reduction, and/or equalization (the resulting sound, though not perfect, is far less noisy than the original).
https://en.wikipedia.org/wiki/Chevrolet_big-block_engine
Wikipedia license: http://creativecommons.org/licenses/by-sa/3.0/
The Chevrolet "Big Block" is a term for a series of large displacement V8 engines that have been developed and produced in the United States from the 1950s until 2009. As American automobiles grew in size and weight following the Second World War, the engines powering them had to keep pace. Chevrolet had introduced its popular small block V8 in 1955, but needed something larger to power its medium duty trucks and the heavier cars that were on the drawing board...
The 396 cu in (6.5 L) V8 was introduced in the 1965 Corvette as the L78 option and in the Z16 Chevelle as the L37 option. It had a bore x stroke of 4.094 in × 3.760 in (104 mm × 95.5 mm), and produced 375 bhp (380 PS; 280 kW) at 5600 rpm and 415 lb⋅ft (563 N⋅m) of torque at 3600 rpm. The solid lifter version was capable of being operated in the upper 6000 rpm range, and when installed in the 1965 Corvette, was factory-rated at 425 hp (317 kW).
Introduced in 1970, the 402 cu in (6.6 L) was a 396 cu in (6.5 L) bored out by 0.03 in (0.76 mm). Despite the fact that it was 6 cubic inches (98 cc) larger, Chevrolet continued marketing it under the popular "396" label in the smaller cars while at the same time labeling it "Turbo-Jet 400" in the full-size cars...
The highly successful and versatile 427 cu in (7.0 L) version of the Mark IV engine was introduced in 1966 as a production engine option for full-sized Chevrolets and Corvettes. The bore was increased to 4 1⁄4 in (108 mm), with power ratings varying widely depending on the application. There were smooth running versions with hydraulic lifters suitable for powering the family station wagon, as well as rough-idling, high-revving solid lifter models usually applied to a minimally equipped, plain-looking, two-door Biscayne sedan fitted with the 425 hp (317 kW) version of the 427 - (RPO L72).
Perhaps the ultimate 427 for street applications was the 435 bhp (441 PS; 324 kW) at 5800 rpm and 460 lb⋅ft (624 N⋅m) at 4000 rpm of torque L71 version available in 1967 to 1969 Corvettes, and in the Italian Iso Grifo. This engine was identical to the 425 hp (317 kW) L72 427 (first introduced in 1966), but was fitted with 3X2-barrel Holley carburetors, known as "Tri-Power", in lieu of the L72's single 4-barrel carburetor. Both engines used the same high-lift, long-duration, high-overlap camshaft and large-port, cast-iron heads to maximize cylinder head airflow (and, hence, engine power) at elevated engine-operating speeds. Consequently, the engines offered very similar performance and resulted in a car whose performance was described by one automotive journalist as "the ultimate in sheer neck-snapping overkill". Typical magazine road tests of the day yielded 0-60 mph (97 km/h) in 5.6 seconds and 1⁄4 mile (402 m) in 13.8 second at 104 mph (167 km/h) range for both the L72 and L71.
In 2011, Super Chevy Magazine conducted a chassis dynamometer test of a well documented, production-line, stock but well-tuned L-72 "COPO" Camaro, and recorded a peak 287 hp (214 kW) at the rear wheels, demonstrating the substantial difference between 1960s-era SAE "gross" horsepower ratings and horsepower at the wheels on a chassis dynomometer. Wheel horsepower (which is obtained at the drive wheels and thus takes into account drivetrain power loss) does not equate to SAE net HP (which is horsepower at the flywheel, like SAE gross, but with all accessories included, unlike SAE gross).
The RPO L89 was an L71 fitted with aluminum heads. While this option produced no power advantage, it did reduce engine (and hence, vehicle) weight by roughly 75 pounds (34 kg). This resulted in superior vehicle weight distribution for improved handling, although the difference in straight line performance was negligible.
The 1969 ZL1 version of the 427 engine was developed primarily for Can-Am racing, where it was very successful in cars like the McLaren M8B...
