Advanced engine design used overhead cams, an aluminum crankcase, liquid cooling
Aerial combat advanced at an astonishing rate during World War I, and though it seems unimaginable today, there were no American-designed aircraft deemed suitable for battle in the skies over Europe. There was a U.S.-designed engine in the fight however: the Liberty V-12 or L-12.
The L-12 engine was America’s greatest technological contribution to the aerial war effort. Its initial assignment was powering the “Liberty Plane”—a version of the British-designed De Haviland/Airco DH-4 bomber produced in the U.S. by Dayton-Wright in Dayton, Ohio; Fisher Body Corporation in Detroit, Michigan; and Standard Aircraft in New Jersey. In addition to powering the DH-4 and a variety of other airplanes, over its long service life the L-12 powered tanks, high-speed watercraft, and land-speed racers.
The L-12 came about because Packard’s head of engineering, Jesse G. Vincent, recognized the need for a standardized line of aircraft engines that could be mass produced during wartime. The government assigned Vincent the task of creating this engine and teamed him up with Elbert J. Hall of the Hall-Scott Motor Company. The two met in Washington, D.C., on May 29 and, with the help of volunteer draftsmen, created detailed drawings and a full report by May 31. This original design was a V-8, but in their report Vincent and Hall outlined how the engine could be configured as a four-, six-, eight-, or 12-cylinder engine.
By July 3, a V-8 prototype assembled by Packard was running, and a V-12 soon followed. Due to its superior horsepower potential, the 1,650-cu.in. V-12 was given the nod for mass production
Not only did the Liberty engine mark a great achievement for American aviation, it was responsible for creating a landmark car company: Lincoln. Henry Leland, who founded Cadillac, and his son Wilfred started Lincoln with a $10 million government contract awarded to build Liberty engines. The Lelands left Cadillac to form Lincoln because General Motors President William C. “Billy” Durant was a pacifist and initially rejected the government’s call for GM to build L-12s. (Durant later recanted and Liberty engines were manufactured by GM.) Production numbers seem to vary for output before and after the war but in total Ford, Lincoln, Packard, Marmon, and Buick produced 20,748 L-12 engines.
At first glance, the engine looks like one of the Offenhausers that dominated midget racing from the 1930s to the 1960s.
I walk around the inline-four, observing its profile—a pair of slim, cylindrical cam covers balanced on top of a tall, narrow crankcase. Closer inspection reveals that it’s not an Offy at all. On the contrary, it’s a slick, remarkably clever motor that woulda, coulda, shoulda replaced the American four-cylinder if World War II hadn’t come along at just the wrong time.
“It was supposed to be the next-generation midget engine,” says Gary Schroeder, who owns the motor.
“The Offy has two valves per cylinder and three main bearings. This has four valves per cylinder and five main bearings. It has a main-cap-style crankcase instead of a barrel crankcase. The cams are lubricated with pressurized oil instead of spreading the black stuff with a scavenge pump—which was a known shortcoming of the Offy. The engine even has insert bearings (instead of Babbitt bearings), which was really unusual back in 1939.”
Schroeder retired a few years ago, after decades of machining bulletproof steering boxes, torsion bars, springs, and a host of other race-car components at various shops in Burbank, California. He also enjoyed a long career as a midget driver here in the states and in New Zealand. And as the son of Gordon Schroeder, he’s a member of American circle-track royalty.
Gordon Schroeder was a young draftsman and would-be race-car builder who made his first foray to the Indianapolis 500 in 1938 to help driving legend Ted Horn. Soon thereafter, he joined crack crew-chief Riley Brett in an effort funded by wealthy sportsman Alden Sampson to escape from the long shadow cast by Harry A. Miller.
Miller was the foundational genius of American racing, and the magnificent cars he designed and built in the 1920s set standards that beggar belief even today, a century later.
Miller was a maverick, but he wasn’t a one-man band. His empire was based on a triumvirate, whose other members were almost as influential as he was. While Miller was the protean big-picture man, mild-mannered engineer Leo Goossen put Miller’s ideas onto paper and virtuoso machinist Fred Offenhauser transformed the drawings into metal masterpieces.
After the stock market crash of 1929, racers could no longer afford Miller’s jewel-like straight-eight engines. Offenhauser struck out on his own to build automobile versions of the robust four-banger that Miller had developed for boat racing. This so-called Offy quickly emerged as the 800-pound gorilla of American motorsports.
Everybody wants more power, and that attention has usually been paid to the romance items like cylinder heads, intake manifolds, carburetors, and camshafts. While those aspects of the engine are still essential for moving air, more engine builders are now scrutinizing the combustion space and making sure that all that air and fuel you worked so hard to get into the cylinder actually contributes to shoving the piston down instead of leaking past the rings.
Are thinner piston rings really better?
In the muscle car days of the ’60s and ’70s, production top and second piston rings measured 5⁄64-inch, and this remained the standard for decades. But with the coming of the modern engine era with powerplants like the GM LS, Ford modular V-8, and the Chrysler Gen III Hemi, piston rings began to slim down for many excellent reasons. If you don’t retain anything else from this story, just remember that thinner is better.
To get an idea of the benefits of slender ring packages, let’s start with some basic concepts. A thick piston ring, like the older 5⁄64-inch designs, presents a very wide contact face to the cylinder wall. This requires significant internal pressure exerted by the ring, called radial tension, to help seal the ring to the cylinder wall. The people at Total Seal have invested in an expensive machine that measures this tension and expresses this tension in units of pound-force (lb-f). Simply stated, this is the amount of force in pounds exerted against the cylinder wall after the ring is squeezed into the cylinder. This lb-f number is not a torque number (expressed as pound-feet or lb-ft) so don’t be confused. Nor is pound-force a sliding friction number, though clearly it is directly related to the friction generated as the piston and ring package move up and down in the cylinder
Before we get into the actual numbers, it’s important to understand why a thicker ring must exert a greater force. This force is directly proportional to the ring face area that contacts the cylinder wall. This might be best explained by using the comparison of two different shoes. When walking on damp grass, it is easier to navigate the surface in a typical flat shoe. However, if the point of the heel is narrowed, as in a high heel shoe, the situation changes: the wearer’s gait is changed and the force of the heel is concentrated in a much smaller area, which easily presses the heel into the soft ground.
A wider piston ring must use a much greater radial tension to apply sufficient load to the cylinder wall to help seal the ring against cylinder pressure. With a thinner design like a 1.0-mm top ring for example, its static radial tension can be substantially reduced because the area of the ring face contacting the cylinder wall is far less than the larger 5⁄64-inch ring.
Piston ring radial tension, sliding friction, and oil control
Again, this radial tension is not the same thing as sliding friction, like that which might be measured with a fish scale pulling a piston with rings up a cylinder wall. But these radial tension loads are still proportional to sliding friction. As a practical example, we’ve installed 4.010-inch LS pistons using a ring package with 1.5 mm top rings, 1.5 mm second rings, and 3.0 mm oil rings into a bore and then pushed the pistons in using mere thumb pressure. But similar bore-size engine using 5⁄64-inch top and second rings and standard tension 3⁄16-inch oil rings demand a hefty hit with a hammer handle to drive the piston into the bore. The difference is the amount of friction produced by the different ring packages. Another way to measure this friction would be to use a digital torque wrench to gauge the friction required to rotate all eight pistons.
A typical small-block Chevy with 5⁄64-inch ring package might require a torque reading of 20 to 25 ft-lb but an LS engine with a 1.0-mm ring package with a similar bore and stroke may require 8 to 10 ft-lbs less torque. At 5,252 rpm, 10 lb-ft of an engine’s torque output is equal to 10 hp. This is not free horsepower because thinner ring packages do cost more and may require new pistons, but other than cost, there are no negatives to this approach.
As an additional benefit, thinner rings also allow the move to higher quality ring materials. As an example, budget ring packages costing $50 most often use grey cast iron that’s rather weak and brittle. Upgrading to a ductile iron will more than double its tensile strength. Plus, many high-quality thinner rings are now made using steel alloys with high-tech face coatings to further reduce friction while improving cylinder pressure sealing capability
In part one of this video segment, Pete Aardema will explain the development of his 93-year-old Ford Model A engine that is officially in the books as the fastest Ford Model A on the planet with a record speed set at Bonneville in August of 2012 at 238.598 mph. Remarkably a top speed of 240 MPH was measured on the back up run. Several years ago, Pete and Kevin modified this 1929 Model A engine and made special cylinder heads with dual overhead cams and achieved a land speed record of 238.598 MPH at Bonneville. This was all done in a blown gas streamliner in the vintage four-cylinder classification which is designated for pre-1935 four-cylinder engines up to 220 cubic inches in displacement. In part two of this video, Pete and Kevin will disassemble the engine and you will see how this one-of-a-kind masterpiece was constructed.
Using 22 different archived videos spliced together this video depicts the Model A engine being produced, from sand molds to being dropped in a chassis. Every Model A engine destined for one of Ford’s 30+ US assembly plants was cast and assembled at the Rouge Plant in Dearborn, MI. Make sure to look out for the main bearing babbitts being poured, the flywheel being balanced, and the manifolds being assembled. How did we do? A Model A is dedicated to the history of the Model A Ford using historical images and videos as well as modern resources.
In this video, we will take you behind the scenes and disassemble this one-of-a-kind engine design revealing some cool stuff. You will see how the worlds fasted Ford Model A engine was redesigned by Pete Aardema and Kevin Braun. This 93-year-old engine is officially in the books as the fastest Ford Model A on the planet with a record speed at Bonneville of 238.5 MPH. Pete and Kevin we will take us through the build process and disassemble the top end and explain how they redesigned this engine which incorporates a unique cylinder head that may be the only 3-piece cylinder head of its kind the exist on this planet. For more information, please review part one of this video to hear directly from Pete Aardema how this engine design came about.
The 1960s was a transformational period for the automotive industry as muscle cars became more popularized. The average consumer went from demanding a sleek, high-speed vehicle to requiring more power and acceleration from their cars. It was the dream of every young driver to have a muscle car parked on their front pouch. Those manufactured between the 60s and 70s became very popular because of their exemplary performances on the road. Here are the most popular muscle cars with engines that will blow your socks off
WHAT MUSCLE CAR ENGINES ARE MOST ICONIC?
THE FORD FLATHEAD V8
The Flathead V8 from Ford is among the most iconic old-school muscle cars with an out-of-this-world engine. The first of these ford engines were manufactured in the early 30s, and its improvement spread to the 50s. One of the most significant roles this engine has in the automotive industry is its impact on the hot-rodding culture.
Although the V8 engine featured in this vehicle doesn’t maximize performance, its authenticity and retro style make it outstanding. One aspect distinguishing it from other engines is its intake and exhaust pipes inside the engine block. Most units have these components on the engine’s cylinder heads.
DODGE 426 HEMI
The Dodge 426 Hemi is another high-performance engine featured in several muscle cars. It is a famous unit that guarantees animal-like power under your car’s hood. It was easier to spot a muscle car fitted with this Dodge engine in the 60s and 70s than it is now.
The 426 Hemi compared to other top engines from Dodge, like the 440 V8 manufactured in the same era. The 440 V8 went ahead to replace the 426 Hemi in the market because of its affordability, reliability, and good performance scores.
FORD 302 CUBIC INCH V8
Most of the engines fitted in muscle cars were V8 engines, and so was the Ford 302 engine. It was an outstanding engine dominating the American automotive culture for decades. You can find the engine in modern Ford’s like the Raptor F-150 and Mustang and other Ford units produced in the late 60s.
The 302 V8 engine size is not as substantial as other manufacturers’ units. However, you can achieve higher performance than engines in higher classes with the correct modifications. The base motor reliability and durability of the 302 are forever unmatched.
CHEVROLET LS V8
The Chevrolet LS V8 is an engine featured in several vehicles, including numerous muscle cars. These engines are more compact and lighter than most V8 engine replacement units, making them popular across the United States. Despite its compact size, the power generated from this engine is enough to power your mid-sized SUV. It is an ideal replacement consideration for any V8 Chevrolet engine if you want to save money, although others find it uncreative
2022 will mark the 106th running of the Indianapolis 500. Before we watch 33 drivers in their cutting edge wings on wheels scream around the track at 230mph, we always love looking back on how we got here. In this case, we’re going to focus in on a few engines from the Museum of American Speed that highlight a few of the incredible technical advances that have taken place over the years.
Miller Flathead Ford (1935)
This engine lived in what were among the most beautiful cars to ever lap the Brickyard. We’ve talked about the ‘35 Miller Fords before, but we never get tired of looking at the hopped-up flathead Ford that ran Indy. These engines used finned aluminum Bohnalite heads and three-carb manifolds and were remarkably similar to the engines that hot rodders were beginning to stuff in their cut-down T roadsters and Deuce coupes.
We all know how this story ends. In their haste to develop the cars before the ’35 race, the crew managed to overlook a steering knuckle that was perilously close to the exhaust, which eventually took them out of the race. A sad engine for an otherwise great story and a few exceptionally beautiful cars.
According to Andy Granatelli, “The Novi did everything but win races.” In fact, they developed a reputation as being cursed; regularly that fastest and most powerful thing on the track, but never actually winning Indy. That didn’t stop them from becoming fan favorites, in large part because these things absolutely screamed. Literally. Not only did the massively oversquare 4-valve DOHC V8 have a sound all its own, but that huge centrifugal supercharger was turning more than 5-times the speed of the engine. That worked out to a 40,000-plus rpm siren that could be heard for miles.
Before it was called the Novi, the platform was developed by businessman Lew Welch, along with engine mastermind Leo Goossen and Bud Winfield. Interestingly, the engine’s first appearance at Indy was in a refugee Miller-Ford (see above). In 1941, this monster was making 450 horsepower, way more than a contemporary Offy, and also more than the old front drive Millers could handle.
Many attempts were made to tame the Novi for Indy, ultimately culminating in the monstrous, 700-horse Granatelli four-wheel-drive cars of the mid-60’s. Crashes and bad luck continued, and the last appearance for a Novi at the Speedway was ’66.
More Leo Goossen magic, this time perched atop a stock Studebaker V8 block. We might not all think of exotic, high-winding Indy engines when we think of Studebaker, but Indy legend J.C. Agajanian saw potential and commissioned Goossen to develop this beautiful design. The DOHC heads were designed by Goossen and bolted to the 274-inch stock block Stude. Straight-cut gears spun the cams and it was topped with a Hilborn injector.
The engine was fitted to an Eddie Kuzma chassis with Allen Heath in the driver’s seat. Unfortunately, the rig didn’t get very far; the starter broke the snout off the crank during qualifying.