I had a bookend experience with the most mass-produced car engine in human history. In 1955, the year Chevrolet introduced its first modern V-8 engine, GM’s highest volume brand delivered 1.68 million cars. Since the V-8 cost only $100 or so more than the standard “stovebolt” six, my rough estimate figures that more than a million of the new 4.3-liter V-8 engines were built and sold in its inaugural year.
I was fortunate enough to own one of those small-block V-8s among the first million. In 1960, at the tender age of 15, my father finally caved in to my relentless begging for a car. Instead of condoning the purchase of the Ford Model A—which I intended to convert to a hot rod—he hauled me off to a nearby used-car lot where we purchased—using the funds I had earned mowing lawns for several years—a ’55 Chevrolet which, as luck would have it, was well on its way to becoming the hot rod I never imagined.
In addition to the lowered suspension, dechromed exterior, side pipes, floor-mounted shifter, and extra gauges gracing this Chevy, it was equipped with the essential V-8 engine. Even though that two-barrel small-block made only 162 gross hp (138 net), it had more than enough gusto to introduce this greenhorn to the joys of speed, street racing, and car enthusiasm.
Don Sherman's 1955 Chevrolet
Leaping ahead by a half century, I participated in the epic and painstaking assembly of the 100 millionth GM small-block V-8. A cast of dozens—luminaries, engine-department retirees, journalists, and reprobates—was invited to GM’s Performance Build Center in Wixom, Michigan, to lay hands on the 638-hp supercharged and intercooled 6.2-liter LS9 V-8 tapped for perpetual museum display as the 100-millionth example from a distinguished line of engines.
My piece of the action was the installation of the number-six piston and connecting-rod assembly.
Wixom is a surgically clean factory where the low-volume LS7 (the 7.0-liter, 505–hp Corvette Z06 small-block) and LS9 V-8s are assembled. In fact, customers who might enjoy building their own engines can do so by checking the appropriate option box when ordering a Corvette powered by one of these special eights.
Dropping the No. 6 piston-and-rod assembly into its assigned space was child’s play, especially for a child that has assembled dozens of engines—including a few small-blocks—over the years.
The host block was supported on a rotisserie-type fixture that could be conveniently rotated to orient the target bore horizontally. The crankshaft, camshaft, and first five piston and rod assemblies were already in place. Also, some kind soul had preassembled the rod to the piston and fitted the piston with rings, two tasks that demand skill, experience, and special tools.
Preparing for insertion, I swabbed the rings, piston skirt, and connecting rod-bearing insert with an assembly lubricant manufactured by Lubrizol. Next, two assembly aids were added. A plastic guide tool slipped over one of the protruding bearing-cap retaining screws avoids damaging the crank journal and piston oil squirter during the insertion process. And a conical sleeve device held securely against the block’s deck surface as the piston-rod assembly is guided into its bore also expeditiously compresses the piston rings.
The guide tool helps the assembly index itself to the proper orientation as the connecting rod’s big end engages the crankshaft journal. After it is properly seated with the rod touching the crank journal and the piston fully within its bore, the guide tool and conical sleeve can be removed. Then the rod cap is lubed and slipped over the two retaining bolts. Adding two nuts and torquing them to the proper specification with an automatic air tool completed my task.
Once my job was finished, I vacated the assembly line so others could play their part in this grand pageant. My only regret is that this powerhouse probably will never see service or life on the road. That’s the price of fame; now that this engine has been given celebrity status, its job will be to provide small-block admirers something to see and touch for now and evermore.
1955 The original (GEN I) 4.3-liter small-block powers more than a million Chevy sedans, pickups, and Corvettes. Gross output ranges from 162 to 195 hp.
1957 An uprated 4.6-liter engine with optional mechanical fuel injection achieves one hp per cubic inch (283 hp).
1962 Increasing the bore and stroke ups displacement to 5.4 liters (327 cubic inches), yielding 360 gross hp with fuel injection.
1965 The small-block name is coined to distinguish Chevy’s existing V-8 from a new 6.5-liter “big-block” engine. Tuners affectionately nickname the motors “mouse” and “rat.”
1971 The arrival of lower compression and SAE net hp procedures cripples power ratings. The 5.7-liter LT1 engine introduced in 1970 for Camaro and Corvette drops from 370 to 330 hp.
1975 Strangled by a single-catalyst exhaust system and other emissions controls, the standard Corvette 5.7-liter V-8 produces 165 hp. A 4.3-liter V-8 installed in Chevy Monza and Nova cars delivers an uninspired 110 hp, the small-block’s low ebb.
1986 Corvette cylinder heads change from iron to aluminum.
1992 The GEN II small-block arrives in the new Corvette with reverse-flow cooling, all-new cylinder heads, computer-controlled ignition, dual catalysts, 300 hp from 5.7 liters, and an LT1 designation.
1997 Little more than the 4.4-inch bore spacing—a feature common to all small-block V-8s—carries over to the new LS family of GEN III engines. Key improvements are a deep-skirt block (aluminum in some applications), iron cylinder liners, main bearing caps retained by six bolts, and rearranged intake and exhaust ports. The 5.7-liter Corvette engine produces 345 hp. In 1999, all-new 4.8-, 5.3-, and 6.0-liter versions are introduced for SUV and truck applications.
2005 GM designates the 5.3-liter small-block incorporating cylinder deactivation a GEN IV design. A 6.0-liter Corvette version fires on all cylinders to deliver 400 hp.
2006 The 7.0-liter LS7 V-8 introduced for the new Corvette Z06 delivers 505 SAE-certified hp.
2009 The supercharged and intercooled 6.2-liter LS9 V-8 introduced for the Corvette ZL1 produces 638 hp, the small-block’s high-water mark.
2013 The GEN V small-block V-8 is expected to appear under the hood of a new seventh-generation Corvette. GM has acknowledged investing more than $1 billion in updated manufacturing facilities. Also, the move to direct fuel injection and aluminum-only cylinder blocks has been confirmed. What remains unknown is what GM means by the “advanced combustion system” touted for this engine. We believe that connotes a significantly higher compression ratio, revised combustion chambers, smaller piston displacement (5.5- to 6.0-liters), power comparable to today’s engines, and significantly better fuel efficiency. Stop-start, cylinder deactivation, and some means of varying valve timing and lift are all expected. Abandoning classic single-cam, two-valves-per-cylinder architecture is, however, not expected.
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