We're living in the Golden Age of Horsepower. No other time in history has witnessed how horsepower from an internal combustion engine has been so easy to achieve. This didn't happen overnight, however, and to really appreciate the evolution of horsepower, do yourself a favor and spend a day at Bill Smith's exceptional Museum of American Speed any time you're near Lincoln, Nebraske. A wise man once said that in order to know where you are going, you really need to know where you've been. The late Bill Smith has done that with an emphasis on early American circle track racing history and an astonishing collection of high performance engines.

After spending the better part of a day investigating engines with the museum's John Mackichan we assembled a challenging list of a dozen engines that impressed us the most. What we have left out would easily fill volumes, including an entire room devoted to Harry Miller, the man behind the engine eventually known as simply the Offy. Fred Offenhauser worked for Miller and eventually bought the tooling Miller used for his early Indy 500 race engines. Offenhauser, with immense help from Leo Goossen, designed and built the legendary Offy that was the engine of choice at Indy for entire decades from the 1930's up through a turbocharged Offy winning Indy in 1976.

One of these engines dates back almost an entire century, while others are so unique you may wonder why you've never heard of them. If this ignites an interest to know more, then we've accomplished our task. The hard part was limiting our story to a mere dozen engines. Most importantly, take a moment to appreciate the enormous effort required to build such an impressive museum so that future generations of car crafters can marvel at the accomplishments of the men who came before us. Bill Smith has passed away but his legacy continues with his phenomenal museum. It was truly an awesome automotive experience.

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See all 17 photos Mickey Thompson Hemi 427 FordThe more you learn about Mickey Thompson's automotive accomplishments, the more you have to be impressed. In the early '60s, he created a hemi head conversion for Pontiacs. After switching to Ford backing in 1963, he quickly altered his original deisgn to adapt a hemi head to the 427 FE Ford. The conversion demanded what was called an articulated pushrod design. This is engineer-speak for a three-piece pushrod configuration! The center rod is captured in the head with separate extensions from the lifter to the middle and from there to the rocker arm. According to Ford collector and ex-Thompson employee, Scott DaPron, Thompson only cast four pairs of these heads, making them ridiculously rare and collectible. Testing proved the pushrod solution was problematic, ending the development effort.

See all 17 photos Plymouth-Weslake DOHCIn 1969, Richard Petty decided to drive a Ford in NASCAR, so Plymouth used that budget to fund the development of an Indy V8 engine. They partnered with Harry Weslake's British engineering firm to develop a DOHC cylinder head and induction system for the small-block Mopar. This was intended for Andy Granatelli's STP team. At both 318 and 327 cubic inches, it's claimed 600 peak horsepower was down compared to contemporary race engines, so it wasn't competitive at big speedways like Indianapolis. However, the engine did make excellent torque and driver Art Pollard used that to help win at Dover Downs International Speedway in Delaware 200 in August, 1969 before the engine was retired. Oddly, a drag race version appeared for a short time in a D/Altered Colt station wagon campaigned by the Rod Shop that same year, appearing in a July, 1971 Car Craft story.

See all 17 photos First Chevrolet V8If you think the first overhead-valve Chevy V8 debuted in 1955, you've missed the mark by nearly 40 years. Chevrolet produced this amazing 55 HP, 286ci production engine in 1918. As you can see, it sports an exposed valvetrain using shafts to support the rockers. Before every trip, maintenance demanded oil be squirted manually onto the valves and rockers to lube the valvetrain. The induction is a single updraft carburetor with spark from a Remy (the forerunner to Delco-Remy) points distributor and a Bosch coil. The engine sports three main bearings and the connecting rod bearings were splash-lubed by scoops located in the rod caps that picked up oil from troughs in the oil pan while the mains and the cam were lubed by a small oil pump. Nearly 100 years later, Chevrolet offered a similar displacement 293ci (4.8L) L20 production V8 that makes 285 hp- five times as much power with far more reliability.

See all 17 photos ARDUN Flathead ConversionZora Arkus-Duntov is best known for his performance contributions to the Corvette. But before he went to work for GM, he and his brother Yura created the Ardun overhead valve, hemispherical combustion chamber cylinder head conversion in 1947 for the flathead V8 Ford. The venture was less than successful until C-T Automotive modified the cam and induction and greatly improved the conversion's durability and power. Today, the Ardun conversion is viewed as a link connecting pre-war flatheads to '50s OHV production engines. There was even an Ardun of Europe conversion. A typical flathead Ford V8 (1932-'37) was 221ci and made 85 hp. The Ardun conversion made 160 hp during Duntov's initial dyno testing.

See all 17 photos

See all 17 photos

See all 17 photos Ford SOHC 289By 1964, it could be said that Ford had the domestic overhead-cam market covered. Most know about the original Cammer SOHC 427 engine that still has a following with blue oval nostalgia fans to this day. The concept was that if the cams were positioned above the valves, the heads could have larger intake ports and the engine could potentially make much more horsepower, especially at higher engine speeds. Just as importantly, those bothersome pushrods could be eliminated. By 1968, Ford produced three SOHC prototype small-blocks. With a 4.00-inch bore and 2.87-inch stroke, this short-stroke 289 was designed to make power at engine speeds of 6,500 rpm and higher. A shaft in the original cam position is used to drive each of the overhead cams using Gilmer belts (instead of chains used in the 427). The dummy central shaft also turned the oil pump. Of the three prototypes built, the Smith Collection reports this is the sole survivor.

See all 17 photos Chevrolet V-16It's hard to call this behemoth a small-block. Al Mathon Sr. and Jr. of Long Island, NY took on the challenge of welding two small-block Chevy 350 blocks together to create this 700ci torque monster. This is a fully functional engine that made over 500 horsepower on Bill Mitchell's engine dyno several years ago. The separate cams and cranks are timed 45 degrees apart to create this firing order:1-9-8-16-4-12-3-11-6-14-5-13-7-15-2-10The wildest component might be the giant 16-position distributor cap. As strange as it sounds, Cadillac put a V-16 into production between 1930 and 1940 displacing 431 and 452 cubic inches. The concept was to produce an incredibly powerful and smooth running engine.

See all 17 photos Olds 215ci Midget EngineWith the introduction of the midsize Buick Special, Pontiac Tempest, and Olds F-85 in 1961, each model had its own unique engine and powertrain, including the Oldsmobile all-aluminum 215ci V8. The engine featured a 3.50-inch bore coupled with a very short 2.80-inch stroke that eventually made 200 hp in its 11.0:1 compression version. Midget racers looking for a less expensive alternative to the Offy tried running these engines with mechanical fuel injection on methanol. Despite the fact that the engine weighs less than 330 pounds, it was still too much for those little cars. GM eventually sold the aluminum V8 tooling to Rover in 1967 and late model iterations of this original all-alloy V8 can still be found in Land Rovers in the junkyard and in the British TVR the engine grew to 304ci (5.0L) with race versions as big as 317ci.

See all 17 photos Latham Supercharged Small-Block ChevyNorman Latham developed his supercharger in 1956 with a plan to improve upon the rather inefficient 19th century Roots style blower. Latham's supercharger employed compressor stages similar to those used in jet engines. The cylindrical Latham supercharger uses multiple stages of fixed outer blades combined with rotating internal blades that individually compress the air from the previous stage. Boost is created by adding compressor stages akin to increasing the number of slices of bread in a single loaf. The blower worked well but was difficult to manufacture and required significant compressor speed to produce boost. Latham sold the business to Richard Paul in 1982 who continues to make these little beauties out of his Simi Valley, California Axialflow company (axialflow.com).

See all 17 photos Mickey Thompson's Supercharged Bent FourThere's easily a full-length story in this engine. The museum has created a special place for several notable engine builders, including Mickey Thompson and the engines he created. This unique Tempest four cylinder began life in 1961 as half of a Pontiac 389ci V8. That's interesting in itself, but even wilder is the cylinder head. Thompson built several sets of aluminum hemi heads for the 389 Pontiac. Thompson actually won Top Eliminator title at the 1962 U.S. Nationals beating Don Garlits in the final with a blown, hemi-headed Pontiac built by his long-time engine builder Fritz Voight. This bent four was a spin-off of the supercharged four bangers for Thompson's standing mile record attempts using a full-bodied dragster powered by a 180ci, destroked four. This engine uses a 4-71 GMC blower topped with a two-port Hilborn mechanical fuel injector.

See all 17 photos SOHC Small-Block ChevyFord was not the only OE manufacturer to experiment with a single overhead cam small-block. Chevrolet also tested the concept of moving the cams to the top of the rocker arms. This unique small-block offers casting dates of 1967 right on front of the valve covers. Dual belts drive the cams from a crank-driven gear. The induction is also Detroit esoteric with four pairs of 2-inch Webers feeding the engine. Among others, in 1971 Richard Moser produced a DOHC conversion for the small-block that was relatively successful. Speedway actually raced one of these engines for a time.