Corvette C2 Sting Ray Convertible - 1964.mp4

For the 1966 Corvette, the big-block V8 came in two forms: 390 hp (290 kW) on 10.25:1 compression, and 425 bhp via 11:1 compression, larger intake valves, a bigger Holley four-barrel carburetor on an aluminum manifold, mechanical lifters, and four- instead of two-hole main bearing caps. Though it had no more horsepower than the previous high-compression 396, the 427 cu in (7,000 cc), 430 hp (320 kW) V8 packed a lot more torque – 460 lb⋅ft (624 N⋅m) vs. 415 lb⋅ft (563 N⋅m). In the 1960s engine outputs were at times deliberately understated. This happened for two reasons; to placate nervous insurance companies, and to allow the cars to qualify for lower NHRA brackets based on horsepower and weight.[23] Estimates of 420 to 450 hp (313 to 336 kW) for the 427 have been suggested as being closer to the truth. Conversely, power ratings in the sixties were done in SAE Gross Horsepower, which is measured on an engine without accessories or air filter or restrictive stock exhaust manifold, invariably giving a significantly higher rating than the engine actually produces when installed in the automobile.[24] SAE Net Horsepower is measured with all accessories, air filters and factory exhaust system in place; this is the standard that all US automobile engines have been rated at since 1972. With big-block V8s being the order of the day, there was less demand for the 327, so small-block offerings were cut from five to two for 1966, and only the basic 300- and 350-bhp versions were retained. Both required premium fuel on compression ratios well over 10.0:1, and they didn't have the rocket-like thrust of the 427s, but their performance was impressive all the same. As before, both could be teamed with the Powerglide automatic, the standard three-speed manual, or either four-speed option. Editing Dr. Fernando Menichini.