Evolution of the Vintage Car Engine

Evolution of the Auto Engine

- Useful Advances We Take for Granted

by Igor Spajic

VCH Correspondent

 

When we drive today’s cars with their computer-controlled, fuel-injected, alloy-built engines, it’s hard to appreciate just how far the art and science of the automobile engine has come.

In some basics, of course, it is locked into the mechanical and chemical knowledge of the nineteenth century, for surely by now we should be able to have long-lived, highly-efficient engines capable of 200 miles per gallon. This is possible, but industrial inertia, technical ignorance and suppression of significant advances by the might of the petrochemical cartel have stifled fundamental improvements in automotive engines. All car companies are allowed to do is to make marginal improvements of ignition and fuel delivery via computer control and those metallurgical improvements that cut weight and manufacturing costs (but only if they cut both weight and cost at the same time).

The stifled development of the internal combustion engine is a topic for another day and another article. What we will focus on here is the progress that has been made – and it is still considerable.

Electric, Steam or Gasoline?

Let us look now at the first National Automobile Show held in America – New York, 1900. The streets outside were filled with horse-drawn wagons, hansom cabs and omnibuses. Electric tramcars plied their routes as did the underground railways. Cyclists rode their light, spindly machines. People walked or occasionally rode horses. The smell of horse manure was everywhere. So was the attendant risk of disease.

Within the auto show, for the first time in any numbers, Americans examined the newest fad to come out of Europe – the self-propelled carriage. Small by today’s standards, the automobiles of 1900 were little more than powered buggies. Many used bicycle-like wheels and suspensions. Open to the weather, with no enclosures of any kind, these cars were ridiculously underpowered. They were barely able to propel their own weight, let alone carry human passengers and – god forbid – any cargo. 30 mph could be achieved but not uphill. Bridging long distances was still the exclusive preserve of the railway – or the steamship. Automobiles seemed like more of a toy than a proper conveyance.

Those few cars that were enclosed were modelled after the hansom cabs and horse-drawn broughams of the time and were critically heavy and lumbering vehicles. Their gas or electric engines could propel them at the speed of a canter, even a gallop on good road surfaces, but no more.

Polled on their preference of what motive power they wanted in their automobiles, visitors to the show overwhelmingly chose the electric, followed by the steam engine. Only 5 per cent voted for the internal combustion engine. It’s not hard to guess why. Electrics were smooth, silent, odourless and simple to operate. Steamers were powerful, relatively silent and reliable. Though not simple to operate and maintain, yet they were a known quantity, with a century’s mechanical experience behind them.

1904 gasoline cars pg-10

By 1904, gasoline cars were becoming preferred. Some excellent examples are here.

‘Gasolene’ or ‘petroleum’ engines were difficult to start, noisy, shook the car and needed gear-changing to match the engine’s narrow torque curves with road speed. They used unreliable electric ignitions to detonate their fuel mixtures and seemed just as likely to explode because of those volatile fuels.

Officials of the auto show took no chances either; they always arranged for a bucket brigade to stand by when a gasoline car was being crank-started. One critic wrote that the internal combustion engine was “noisy, unreliable and elephantine, it vibrates so violently as to loosen one’s dentures. The automobile industry will surely burgeon in America but this motor will not be a factor.”

By 1903 however, the tables were turning. As the gas engine was demonstrating increasing strengths, so the electric and the steamer were demonstrating increasing weaknesses.

The electric foundered on its limited range and low speed; directly attributable to the low energy density of the heavy, lead acid batteries it was forced to carry. Hours were needed to recharge the batteries and the electric car was forced into a narrow niche of preferred town car for society matrons and elderly gentlemen.

The steam car was fairly silent and quite powerful, but was complicated to run and service. Its myriad pipes and boilers needed frequent cleaning due to the deposits left behind by the hard water coming from domestic faucets and water bores alike. A steamer needed time to build up a head of steam and under certain circumstances (more likely through lack of maintenance) could explode. For the increasingly impatient motorist, the steamer was not the answer.

By 1904, the New York Automobile Show demonstrated just how much the industry had changed since 1900. Frank Leslie’s Popular Monthly listed 73 makes in January. Of these, 8 were electrics, 4 were steamers and the rest (61) were internal combustion engined. Of the latter, the majority were four-stroke instead of two. The new orthodoxy had established itself remarkably quickly.

Excepting the persistence of the Stanley brothers and the White Company, by 1910 there were virtually no steam cars being built in the United States (or the rest of the world for that matter). The remarkable improvements and performance of the Doble steam cars in the 1920s came too late to change anything and served only as an engineering curiosity.

As for the electrics, they lingered on as town carriages well into the Teens, until finally, the self-starting petrol cars saw them off as increasingly unnecessary.

1904 steamers - electrics pg-21

By 1904 steamers and electrics were in the minority. Columbia and National would soon drop their electrics for all gasoline; Woods and Waverley would last about another decade as electrics; and Stanley would be a steamer to the bitter end.

As we have seen, the triumph of the gas engine was not an overnight event, nor even apparently a sure thing.

Things began in 1860, when Etienne Lenoir built the first four-wheeled vehicle to be powered by a gas engine of any description. A primitive carburetion system introduced air and gas vapour separately into the combustion chamber of the two-stroke engine. It was water-cooled but through water injection. The Frenchman used both methods to keep his one-cylinder unit from pre-ignition – a perennial problem that would dog engineers for many years afterwards.

By 1903, motor car engines were usually water-cooled through circulation of coolant, and the mixtures ignited by electric spark, timed through increasingly complicated trembler coils and distributors. The engines could run at varying speeds thanks to improvements in carburettor control.

Two typical American cars of 1903 are the first Ford and Cadillac. Both these ‘Model As’ used a four-stroke, water-cooled, twin-cylinder engine. It was a flat, opposed motor, aligned along the longitudinal axis of the car, so that the crankshaft was parallel with the driving axle. This simplified the transmission arrangements, which usually employed a chain drive. Mounted in the middle of the chassis, both these engines were literally beneath the driver’s seat.

How Many Cylinders?

By 1906, other changes were manifest. Cosmopolitan magazine released a guide to all the new ‘gasoline motor cars’ available in America, both imported and home-built. One-cylinder ‘bone shakers’ accounted for 13 models; two-cylinder engined cars numbered 54; a minority of five had three-cylinders; and the majority used four-cylinders, with 59 total. Of the rest, a straight-six was marketed by Ford (the unsuccessful Model K) and a V8 was built by Coyote in Redondo Beach, California. National and a few others such as Stevens-Duryea were soon to bring out six-cylinder models too, but this trend (which had started in Great Britain and Europe in 1903) would take a few years yet to play out.

1906 National Model E 6-cyl 50-60 hp

An early adopter of the 6-cylinder engine in America was National, with this 1906 Model E 50-60 hp.

No Gaskets, No Heads

Though the first monobloc engine had been made in 1896 by Charles B. King (later of King V8 car fame), machining techniques had not yet been able to produce cast en-bloc engines without high cost.

As a result, cylinders were cast one at a time and bolted together on a common crankcase. The same manufacturer could offer two-, four- or six-cylinder engines, all using the same cylinder castings. Crankcases and crankshafts were different of course, as was the manifolding for fuel/air/exhaust and the plumbing for cooling could get quite complicated.

Cylinders and cylinder heads were one because no gasket known could seal a join between them. Intake and exhaust valves were set into caps that were screwed into the top of each cylinder/head casting. The intake valves were on one side of the cylinder and the exhaust on the other. Each side had its own camshaft located down in the crankcase, which operated the valves via pushrods. This was called a T-head arrangement.

1908 Ford Ad

Henry Ford was one of the first adopters of the monobloc cast engine. His 1908 Model T led the way.

A non-detachable cylinder head meant that if you wanted to replace worn piston rings, then you would have to take the entire engine apart. Tough luck.

At least the valves were accessible and they needed to be. So as not to damage the valve seats, the valves were fashioned from softer metal alloys. They needed frequent grinding to even out the wear and even then, might last for hundreds of miles in the early years, rather than thousands. New cars might not have come out with folding roofs or even headlamps as standard, but they came with a spare set of valves!

Returning to the question of the monobloc engine, the Ford rates an honourable mention. Though it may not have been the first such auto engine, the 20hp 4-cylinder side-valve engine used by the Model T was the first successful, mass-produced monobloc engine with a separate cylinder head. It was inexpensive to make and made possible with a copper-asbestos head gasket.

Valves Beside or Valves Above?

1912 Peugeot Ad

In 1912, Peugeot knew a lot about racing OHV, DOHC engines. Their Grand Prix racers won the French GP and the Indianapolis 500 that year. The valve arrangement would have to wait many decades before it became the norm on regular production cars.

The T-head engine was simplified into the L-head, a side-valve design with all the valves on one side. Needing only one camshaft and easy access panels to the valve train, the L-head made up for its loss of some volumetric efficiency with a significantly lower production cost.

Though the side-valve became design orthodoxy until the 1960s, even in 1898 its successor was being tried. The Wilkinson Motor Car Co. released an automobile with an engine having both overhead valves AND an overhead camshaft. Relatively simple but highly efficient, this layout appeared to be let down by insufficient standards of metallurgy and machining. The OHV/OHC engine would come into its own in the 1990s and is today the dominant design orthodoxy.

Cooling by Air

When mentioning air-cooled, flat four engines, you might think of Subaru or the Volkswagen Beetle. Try the American manufacturer Knox, who marketed such a model in 1905. The air-cooling was achieved by screwing many corrugated pins into each cylinder wall. For every square inch of cylinder wall, 32 square inches of cooling surface was achieved.

1907 Knox Ad

Air-cooling is touted in this 1907 Knox ad. It’s waterless, you know.

The Knox porcupine engine was joined on the market by Franklin’s air-cooled cars, which used assemblies of finned cylinders, much like a motor-cycle’s. Knox did not last while Franklin endured into the Depression years – with each engine still air-cooled.

Engines on the Square

One of the first ‘square’ engines was sold by Premier in 1906. By ‘square’ we mean an engine whose bore and stroke are of equal dimensions. The Premier’s vertical four-cylinder engine was of 4 ¼” x 4 ¼” (108 x 108mm) and served to reduce piston speeds, allowing for less friction and wear. Long-stroke engines persisted however, as higher torque was more important in the age of crash gearboxes than cylinder bore wear. At least until the post-World War II V8s from Cadillac and Oldsmobile.

Where Goeth the Auto Engine?

In the pioneering years of auto manufacture, the problem of where best to place the engine was a particularly thorny one. If getting it to work properly and reliably wasn’t bad enough, deciding where to put it must have tested the patience and inventiveness of many an exasperated engineer. Does one place the passengers first, then find a place around them to put the motor? Or secure the power-plant in place, then arrange the occupants over or around it?

If placed amidships, the engine was sat upon by the passengers in various awkward arrangements. The 1890s found the French wrestling with this challenge earlier than most – there was dos a dos, where the occupants sat back to back; or vis a vis, where they faced each other (leaving the driver to look over the shoulders of passengers to see where they’re going).

1901 DeDion Bouton Ad

Dos a dos (back to back) was less sociable than vis a vis (face to face) seating, as seen on this 1901 De Dion- Bouton American ad. The third passenger blocked the driver’s view somewhat.

By 1901 the sensible systeme Panhard was coming into favour, which placed the engine out front, where it would seem it belonged. Europe and Great Britain followed, though American manufacturers were still undecided. While a flat twin could still snuggle under the floor boards, a straight-4 was definitely a vertical proposition, and therefore belonged away from the passengers.

As early as 1896 the Hertel carried its engine out the back and ten years later, the Adams-Farwell still used this practice, even though with a flat radial engine, it did not really need to. By this time, though, the systeme Panhard made a lot of sense to the majority of carmakers.

Drive from the Front

Front wheel drive is no new innovation either. Common enough today, front-wheel drive was a BMC staple during the 1960s and a Citroen feature since 1934. Earlier examples in the 1920s by Cord, Alvis, Tracta, DKW and others are preceded in turn by the 1900 Pennington.

The Great Horseless Carriage Company was a British firm formed in 1896 by an infamous financial manipulator called Harry Lawson. Lawson could see the potential of the automobile for making lots of money, like the bicycle fad had done. To this end, Lawson sought a monopoly by attempting to buy up the rights to all automotive patents for the British Empire. Lawson’s syndicate bought both important and worthless patents alike, at inflated prices to make them seem more valuable.

Typical of such folly was the purchase of all the motor patents of American Edward J. Pennington in 1896, for the princely sum of £100,000. Pennington’s motorcycles and ‘Torpedo Autocar’ three-wheelers were generally front-wheel driven by a small engine resting over the front wheel. Despite some extravagant claims and clever marketing by their promoter, Pennington autocars were a failure. The engines were under-engineered and very short-lived; the designs crude, impractical and unfinished. Pennington was a fraud.

1900 Pennington motorcycle

1900 was probably the dying days of the Pennington fraud, when this illustration claimed that a Pennington motorcycle built up enough speed to fly over a 65 ft. wide river. Yokels, boaties and sunday strollers alike are shocked.

The joke was on Lawson, but he didn’t seem to mind. Lawson and his cronies bought and re-sold their patents amongst their own companies, making profits on their dealings at every stage, at considerable cost to the shareholders in those various companies.

But even before the Pennington fiasco, front wheel drive was alive and well with electric and steam-driven carriages of the 1880s and 1890s. It made sense, as horses pulled from the front too – the original front wheel drive.

Power from Octane

1906 Welch Ad

50 actual horsepower! A result of the larger valves and hemi-head of the 4-cylinder Welch of 1906. Note the jump-seat attached to the open door of this limousine.

Compression ratios remained at about 4:1 until the mid-1920s, but not because engineers did not know of the benefits of higher compression engines. These were that of more power output per swept volume by squeezing the fuel-air mixture into a smaller combustion space before ignition. The problem which could not be overcome was the pre-ignition of the mixture if the compression was too high. This was caused solely by the inadequate octane rating of available fuels.

By 1923 however, improved catalytic cracking methods were yielding more petrol from the equivalent amount of crude oil and it was also of a higher octane rating. The addition of tetra-ethyl lead further improved the anti-knock ability of fuel.

Engineers were now able to raise compression ratios for more power from less fuel and also to experiment with improvements in spark and valve timing, hemispheric-headed combustion chambers and turbulence-inducing piston tops. Chrysler’s domed combustion chambers (‘hemi head’) in their side-valve sixes of the 1920s reduced pre-ignition and enabled higher compression for more power. But the first hemi-head may date back to the 1904 Welch straight-4.

Metallurgy and Motors

Metallurgical advancements were crucial in the quest for lighter and stronger frames and lighter, more powerful engines. Cast iron frames had pretty much given way to pressed steel chassis by 1900 for better strength and lightness. Henry Ford specified chrome vanadium steel for the Model T’s structure so that it could be lighter but stronger than comparable light cars.

Aluminium alloy would seem to be a modern material for motor cars. Yet, a surprising number of early cars used cast aluminium body panels to reduce weight. These panels were attached to timber frames crafted by skilled coachbuilders. Pierce-Arrow adopted alloy bodies early in its illustrious history and in the quest for the highest quality standards even had its own aluminium foundry at the car factory.

As engines were refined to operate at faster speeds, so they produced more power from a smaller displacement. Reciprocating weight had to be reduced, so cast iron pistons gave way to lighter, aluminium alloy versions.

Even engine heads and blocks wrought from aluminium were tried, chiefly by Marmon in the Teens and Twenties. Problems with corrosion in the water jackets and uneven expansion and contraction of engine blocks were never completely solved by Howard Marmon, though alloy chassis and body components certainly made his cars a good degree lighter than others of the same wheelbase. Outside the ideal world of the engineer, the greater material cost offset some of these gains. Perhaps it was up to industrial chemistry with the perfection of corrosion-inhibiting coolants that allowed the alloy head to finally take its place atop the cast iron engine block from the 1960s on.

1916 Marmon 34 Ad from Motor Age

Howard Marmon was obsessed with employing aluminium wherever possible to cut weight. He could claim that his advanced 1916 ’34′ model was 1100 pounds lighter than other cars of the same size. Material costs were high, though.

A true pioneer here was Elwood Haynes, co-founder and designer of the Haynes-Apperson car. Haynes had invented stainless steel and various cobalt, chromium and tungsten alloys. He was the first to introduce aluminium alloy into an automotive engine.

Victory over Vibration

The less reciprocating weight, the faster an engine can spin. The faster it turns, the more power and torque it can produce. But the less balanced it is, the faster it turns, the more vibration is caused.

Early crankshafts were simply not balanced. It was enough to fit them with good main bearings. Engines were never more than four cylinders in a row and hardly exceeded 2000 rpm. When six-cylinder power plants came along, the longer crankshafts developed destructive vibration periods as they wanted to whip around like a skipping rope. S.F. Edge, the booster of the Napier car, turned this problem into a marketing asset. A six-cylinder Napier, he said, simply developed a ‘power rattle’.

Longer crankshafts, spinning faster, demanded to be balanced. Thus, counterweights and harmonic balancers were employed to keep vibration at bay.

The brilliant British engineer Frederick Lanchester developed the first vibration dampener in 1895. His flywheel was adapted by Packard for the first production V12 car – the Twin-Six. Packard’s extra flywheel at the front of its motor slipped as it spun, so smoothing out the torsional vibration resulting from the crankshaft.

1926 Cadillac Ad

Cadillac highlights its two-plane crankshaft V8 as the ’90 degree’ engine. Comparing the confidence in buying a Cadillac with the confidence of buying a government bond proves just how much the world has changed since 1926!

Cadillac improved the art of vibration dampening further. Like every other automaker, its V8 crankshaft had its pins all in one plane until 1923. Then it was arranged in two planes to balance out rotational vibration further. This ‘90° Cadillac’ engine was a definite leap ahead and the principle is still in use.

Better Breathing

Multi-valve arrangements are a favourite of Japanese carmakers these days, and also of exotica from Europe going back to the 1970s and 1980s. They are complicated and expensive to build and adjust, but if power output and high efficiency is the primary consideration, multi-valve heads are the only way to go.

Perhaps that’s why 4-valves per cylinder operated by twin overhead camshafts were the defining features in the straight-8 engines of the immortal Duesenberg Model Js of the 1930s.

1917 White Cabriolet Ad

A sixteen-valve, 4-cylinder car may be efficient but not desirable in the luxury car field. This elegant ad for the 1917 White Cabriolet town car could not prevent the company’s move to building trucks only.

But multi-valve motors were brought out earlier, by Pierce-Arrow and McFarlan for the 1920s. These Twin-Valve cars were seen as the solution to more power from existing six-cylinder engines, without the need for costly development of straight-8 or V8 motors.

Indeed, for 1916 White came up with the same solution for its 4-cylinder luxury cars. Fours were no longer cutting it in the fine car class, and White (which had abandoned steam cars some four years before) sought to improve their engine’s output with 4-valves per cylinder. They did so but not sufficiently to find new business. White withdrew from car-making operations after 1918 to concentrate exclusively on trucks.

Other multi-valvers existed on the American market such as the Linthwaite-Hussey of Los Angeles, but these were usually prototypes or expensive, exclusive machines. As Europe was in the throes of World War I no such advancements for private cars were available there.

A Cleaner, Longer Life

What of minor advances? The replaceable-cartridge oil filter enabled car engines to last much longer than before. With contaminants such as dust, grit, water and sediments being removed from the circulating oil, abrasion of bearing surfaces and other critical components was greatly reduced. Chrysler popularised this advance with its first car in 1924. Air cleaner elements soon followed as a further refinement.

1925 Chrysler Ad

In this 1925 ad, Chrysler boasted of its Purolator oil filter and of its air cleaner as well, two advances that greatly extended the life of the car engine.

Another way of removing contaminating agents from oil vapour within the engine was to simply suck them out. Cadillac introduced crankcase ventilation in 1926, which removed wear-inducing water vapour, unburnt fuel and combustion blow-by from engine internals. At first, a road draught tube was set up so that the car’s movement through the air sucked out the unwanted vapours.

This open system was replaced in the early 1960s with a closed system. This ‘positive crankcase ventilation’ piped the gases back into the engine via the intake manifold vacuum to be burnt more completely. A constricted, one-way valve made sure it travelled in the right direction.

Whither Goeth the Auto Engine?

Is there more advancement in store for the automobile engine? Undoubtedly. How little or how much depends on vested interests, powerful lobbies, politics, economics and industrial inertia. Incidentally, also on science and engineering, though sadly, these factors only bring up the rear.

- Principal source: www.motorera.com/history

 

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