Steve Magnante's 1001 Corvette Facts. Steve Magnante
You’re kidnapped and the captors command you to tell a 1953 Corvette from a 1954 just by looking at the engine. Fact 57 could save your life.
58 The 1955 Corvette stands as a transitional model. It wore the early body but stepped up to V-8 power. Although General Motors became conservative with production to ward off an inventory glut, all but 7 of the 700 1955 Corvettes easily bruised European sports cars thanks to the new 265-ci OHV V-8. Arkus-Duntov obtained one of the first V-8 Corvettes and presented it to his wife, Elfie, for daily use. It wore special silver paint and a central racing stripe. Silver didn’t join Corvette’s option list until the 1957 arrival of Inca Silver.
59 Frugal buyers did not special-order the seven 6-cylinder Corvettes built in 1955. Rather, the St. Louis plant had leftover engines and had to “build them out” (as they say in the biz). It was up to dealers to find them homes. Still, buyers saved $135 ($2,774 versus $2,909 for the 195-hp 265 V-8). The seven 6-bangers carried VINs starting with E55. The new V-8s received VINs starting with VE55. In the 1978 Petersen Deluxe Series book Corvette: An American Classic, John Amgwert (of the National Corvette Restorer’s Society/NCRS) reported that five of the 6-cylinder 1955 Corvettes were still in existence at the time of publication, an amazing survival rate.
60 The 1955 arrival of the 265 V-8 brought a superior 12-volt electrical system. That said, the handful of 6-cylinder Corvettes built retained the 6-volt electricals used in 1953 and 1954. This point was crucial during battery, generator, and lamp service and replacement. The 6-cylinder Corvettes were the only 6-volt passenger cars built by Chevrolet in 1955; everything else, even 6-cylinder taxicabs, were upgraded to 12-volt layouts that year.
61 The Corvette’s fiberglass firewall was ineffective at preventing electronic energy from interfering with radio reception. To prevent energy released by the ignition distributor, spark plugs, and spark-plug wires from reaching the radio antenna, an elaborate, multi-piece, stamped-steel shield encased the ignition system on the passenger’s side of all 1953–1955 6-cylinder Corvettes.
62 For 1953, the two-piece ignition-shield stamping was painted blue to match the rest of the engine. For 1954, chrome plating was added for extra eye appeal. However, as supplies varied, many cars were built with half of the shield rendered in chrome and the other half painted blue. There was no rhyme or reason to what was installed by the St. Louis assembly workers other than what was available at the moment. In today’s restoration world, most 1953–1954 Corvettes are shown with chromed shields despite the fact that chrome is incorrect for 1953 production models.
Keeping a lid on radio static, this elaborate chamber encased the distributor and spark-plug wires. The chromed, remote expansion tank was separated from the radiator for hood clearance.
63 When the 265-ci V-8 arrived in 1955, the radio interference issue was even more pronounced, as the distributor now sat less than 20 inches away from the radio receiver. Enclosing the distributor in a chrome-plated metal canister and adopting spark-plug wires with braided metal sheaths solved the problem. This was the first of several different shielding strategies applied to V-8 Corvette ignition systems through the successive years.
64 Chevrolet had running V-8 engines on hand when the Corvette was introduced in 1953. However, they were preproduction forebears of the mighty 265-ci small-block engine that wouldn’t be ready until the 1955 model year. One of these experimental V-8s, with 231 ci, was installed in one of the 1953 Corvette Motorama show cars after its show duties were over. Delays in the official release of the small-block V-8 were the only factor preventing the Corvette from arriving with a V-8 power plant from the start.
65 To improve acceleration, the Corvette-spec cast-iron Powerglide automatic was reprogrammed to remain in Low gear right up to 47 mph under full throttle and not to upshift from Low to Drive before 4,500 rpm. It was also set to kick down from Drive to Low gear at any speed below 50 mph.
66 The Powerglide transmission used behind the new 265-ci V-8 shared the same 1.82:1 Low gear ratio as the Blue Flame 6 but had a different stall speed and improved friction faces to suit the increased torque. Because it lacked an intermediate gear ratio between Low (1.82:1) and Drive (1:1), flooring the gas pedal of any Powerglide Corvette at speeds below 50 mph resulted in a sudden jump in engine RPM that frightened some riders.
67 An early spate of carburetor fires afflicting 1953 models triggered a redesign of the air-cleaner configuration. The trio of bullet-shaped units initially used could drip raw gasoline onto the hot exhaust manifolds below if flooded. To remedy this for 1954 and 1955, the three carburetor mouths were sealed to a horizontal tube that was fed clean air by two chromed circular filter units. A revised camshaft brought power up to 155 hp in 1954.
68 Despite its inline 6-cylinder engine, Earl’s stylists added a touch of V-8 imagery to the 1953 Corvette’s tail by splitting the exhaust system and capping the dual outlets with chrome tips. Although some inline 6-cylinder cars of the mid-1950s (certain low-line Studebakers) emulated dual exhaust tips with stylized rear bumpers incorporating a second dummy outlet, the Corvette dual exhaust tracts were real and fully effective.
69 With use, owners of 1953 Corvettes noticed their cars’ 1-inch tailpipe extensions sucked exhaust fumes into the cabin and deposited soot around the trunk. A remedy appeared midway through the 1954 production run when the length of the tips was extended to a full 4 inches. The extended tips were implemented on 1,523 of the 3,640 roadsters built in 1954 and on all 700 cars built in 1955.
The Corvette featured these slim 1-inch-long exhaust tips in 1953-on in just under half of the cars built in 1954. The 4-inch-long replacements solved exhaust fuming and staining problems.
70 Through the years, Corvettes have worn many legendary external engine-callout emblems. The first arrived in 1955 on 265-ci V-8 cars. To tell the world a V-8 was on board, the standard diecast chrome Corvette fender emblems were enhanced with an oversized, gold-toned “V” applied atop the small V in the Corvette nameplate. Interestingly, the chromed die-cast metal inscriptions were the same items used in 1953 and 1954. The enlarged V was an add-on component. Removing it revealed a standard 6-cylinder emblem with the smaller, integral V.
71 Although it might be easy to make the assumption, the Ardun Mechanical Corporation was not the source of the Duntov cam that grabbed headlines at the 1956 Daytona Speed Week. There, a preproduction Corvette ran a two-way average of 150.583 mph with Arkus-Duntov himself at the wheel. With its .404/.413-inch valve lift, this solid cam was available as Regular Production Option (RPO) number 449 and helped unlock the 265-ci small-block V-8’s breathing potential. The Duntov nomenclature was assigned to the cam because he designed it while he was a GM employee. For a decade afterward, hobbyists loosely applied the term “Duntov cam” to describe small-block Chevy cams with hotter-than-stock specifications. After a decade of (mostly) misuse, the term has passed from the popular lexicon of today, except when used to describe a correctly restored early Corvette equipped with RPO 449. Beyond that, the Ardun Mechanical Corporation was no longer active when General Motors released the cam in 1956. A few years later, at Pontiac, engine development engineer Malcolm “Mac” McKellar was immortalized when a series of his camshaft designs were celebrated with his last name attached.
72 The Corvette’s low, sloping nose and hood line forced the use of a special water pump on 6-cylinder models. To allow clearance between the fan blades and hood underside, the cast-iron pump housing was designed to position the fan pulley shaft’s horizontal axis lower than the pumps used in any other Chevrolet model. Today, reproduction housings are available, but the laws of supply and demand set the price at almost $2,000. Rebuilt original pumps can run as high as $3,000.
73 Tire spin was a problem for racers and overly enthusiastic street drivers thanks to the open-style differential fitted to all 1953–1955 Corvettes. Although Positraction was not officially added to Corvette’s option list until 1957 (a $48.45 upcharge), a handful of Posi cars