Mario Andretti's Indy 500 winning race car. Ford Cosworth V-8 powered
My Longtime Romance with Engines
N. Jeffrey Perry--Motorhead for Life
A site dedicated to those who are fascinated by engines of all types
Note: This site will be updated as drawings and photos of interest are located. Stay tuned!
Caddy 4.9 Allante V-8 neatly installed in Bobby Albrit's 1986 Fiero GT
Automotive Racing Engines
The Modern Formula One Engine
Leave your dog at home! Not only do these engines redline at 19,000 rpms, they idle--IDLE--at 4,000! Weighing only 200-250 lbs, with a stroke of just over an inch, the typical V-10s make an amazing 900 hp. from only 3 liters. Double overhead cams operate four or five valves per cylinder with pneumatic valve springs. After nearly poisoning people with exotic fuels, pump gas is now used without boost or nitrous (all motor). They don’t last long; the blocks are ‘junk’ after but one race—distorted and cracked--but they do get the job done before they die. And when they blow up, at 19,000 rpms, it’s truly spectacular!
The Ford Flathead
“Huh? Why that old thing?” you might ask. Not only was the “Flatty” a highly significant performance engine for decades, the motor was not as simple as most “modern” motorheads might think. For example, how did the exhaust get out of the block? The exhaust valves in this valve-in-block engine were located on the inside, beside the intake valves, but the exhaust ports were on the outside of the block. So how was it done? (I won’t tell.) To improve performance, aftermarket cylinder heads were made in both overhead valve and hemi designs, with a recent, super-trick, supercharged version of this enduring classic running at Bonneville. Not bad for an engine designed in the 1930s!
An Engine Without a Trace of Wasted Motion
It’s the Wankel engine, popularly known as the Mazda rotary, for this Japanese company has done more than anyone else to develop it. A “darling” of the sixties—before the Fuel Crisis hit—American auto manufacturers were planning to introduce a wide variety of rotary engines, from single to 4 rotor beauties with awesome performance (and atrocious fuel mileage--the engine’s chief drawback). When fuel prices went through the roof (to an unaffordable 75 cents a gallon!), the American public demanded economy cars practically overnight. So long to the American Wankel engine. Mazda preserved, however,and what an engine it is: No wasteful, start/stop/start motions of rods and valves are involved, motions that waste energy. The rotor merely orbits about the fixed gears of the housing like a planetary gear setup—elegantly simple and beautiful!
And now the bad new: Poor fuel mileage. The shortcoming has been addressed by Mazda, and with some success. The last version of the super-quick RX-7 got a miserable 11 mpg. The new RX-8, with its side port design, is supposedly far better. Time will tell. Not of concern any longer is the apex seals problem: Mazda has solved this sealing challenge completely, making the engine nearly bulletproof.
Brute horsepower has never been a problem with these engines. The four rotor LeMans race motor, shown below, powered the only Japanese entry to win that prestigious event.
This photo well illustrates the innards of these interesting engines; in this case, a three rotor Mazda race motor.
The Latest Peugot WRC Race Car
Those of you who follow the World Rally Championship know Peugot is a major player. This year's car features something interesting, but first, a little background info: WRC cars are custom built, tube-framed, all wheel drive race cars with four cylinder, turbocharged engines making about 300 hp. (with a restrictor plate). The universal transmission setup for these cars is a 6 speed manual. Peugot has found a way to make so much mid-range torque in their new engine, however, that they have gone to a FOUR SPEED transmission! I have followed motor racing for many years, but I've never heard of such a startling concept.
The World’s Most Successful Racing Engine
No, not the small block Chevy, but the Rolls-Royce R-engine. This remarkable engine had the distinction of holding the world’s absolute speed records in an airplane, in a boat, and in a car AT THE SAME TIME, an achievement will never again be duplicated. The records were:
The air speed record was held by the Supermarine S6B in 1931.
The land speed record was held by Sir Malcom Campbell with his "Bluebird" in 1932, 1933 and 1935.
The water speed record was held by Sir Henry Segrave with his "Miss England II" in 1930 and 1931, and "Miss England III" in 1932. Malcom Campbell then broke the record with his "Bluebird" in 1937 and in 1939.
This overhead-cammed, four valve per cylinder, V-12 engine displaced 2,240 cubic inches and made up to 2,500 horsepower at a high, 3,200 rpms with a weight of 1,630 pounds. A later development of this engine became the war-winning Merlin and Griffon engines.
An Assortment of Aircraft Engines
I have a soft spot for aircraft engines, and why not? They lead the field technological developments in IC engines until jets arrived, had high power outputs and fascinating arrangements. Think dual overhead cams and four valves per cylinder is a recent trend? Not hardly, for several World War One engines used this arrangement—that’s 1918 and earlier. Furthermore, engine blocks and heads were cast in aluminum back then, and superchargers/ turbochargers were already in use. Just take a look at the Napier Lion, W-12 aircraft engine (below) and you'll see what I mean.
The Rotary Aircraft Engine
No, not a Mazda “Wankel” engine, but a multi-cylinder, “backwards” engine that was very popular in WW I. The crankshaft, which was stationary, was attached to the airframe. The cylinders and crankcase, which revolved at 1,200 to 1,300 rpms, had the prop attached to it. Air and fuel (with castor oil lubricant) entered via the hollow crankshaft to the crankcase. It was then ‘sucked’ into the rotating cylinders via automatic (spring-loaded) intake valves. The exhaust valve (and the intakes as well on some later engines) were cam controlled. Weight for these roughly 1,000 cubic inch motors was only 300-400 lbs. for a reliable 100 to 130 hp.
For some reason (perhaps interrupted airflow caused stalling?) throttles were not used on these engines—just a ON or OFF switch. After starting the engine, the ground crew had to hold the aircraft back until ‘she smoothed out’. (From what I read they then had to put out grass fires started by burning castor oil hurled from the whirling exhaust ports—what a show!) To be able to throttle the motor, the pilot was forced to cut the ignition in and out, making that BURRP! BURRP! BRURRP! sound associated with WW I aircraft.
Radial Engines (in General)
In these engines the crankcase is stationary and the crankshaft revolves. Each row of these great ‘round engines’ had an odd number of cylinders for valve timing reasons (it’s complicated to explain) with up to nine cylinders used per row. To make a larger engine several rows were used, culminating in the great, four row, R-4360 (discussed below). Virtually all radials were air cooled, which was a natural since the cylinders stuck out in the airflow like spokes of a wheel. To prevent overheating in the cramped cylinder head area, every radial I know of used only two valves, to allow more cooling fines. Nevertheless, they made excellent power per cubic inch, and per pound.
A few motorhead considerations: Oil tended to collect in the lower cylinders after a shutdown. Standard procedure with most radials was to turn them over a few revolutions, to prevent hydraulic locking a lower cylinder. Long push rods actuated the valves from roller lifters that ran on ‘ring cams’ that rotated about the crankcase; two cams per row. Thermal expansion, as the engine warmed up, increased the valve lash, so novel designs were used to compensate. The crankshaft was a built up affair with roller bearings: one bearing per end for a single row engine, three for a double row, etc. The master rod, with an even number of slave rods attached to it, operated the pistons. The master rod had the only con-rod bearing; the slave rods’ con-rod bearings were in of the master rod itself.
A typical radial was the excellent Pratt and Whitney R-2800, an 18 cylinder radial that produced up to 2,500 hp @ 2,400 rpms from 2800 cubic inches with a weight of 2350 lbs. Known for their exceptional reliability, some R-2800 engines brought their aircraft back with an entire cylinder shot off, the connecting rod merrily flailing away!
The (Mercedes) Daimler-Benz Aircraft Engines
What made these liquid cooled, V-12 engines unique were that they were built upside down (the cam covers were on the bottom, the crank on top) and that most versions of the engine used roller bearings throughout: mains, rods, and wristpins.
Why the upside down design? The low profile improved a pilot’s forward vision in a fighter plane, allowed for engine-mounted cannon to fire through the prop hub (though it never worked right), and provided a lower thrust line for the prop. But why all those roller bearings? One would suspect that German engineers of that period were infatuated with them, or they lacked confidence in sleeve bearings. Either way it was a good thing considering the brutal starting method used with these fuel-injected engines: inertial starting.
To wit: A small flywheel, unconnected to the crankshaft, was spun up to high rpms by two sweating mechanics on a hand crank (like firing up a Model T Ford). The pilot then engaged a clutch that connected the spinning flywheel to the crank. This produced nearly instantaneous results: from zero rpms with no oil pressure, to 800 rpms a split second later STILL WITH NO OIL PRESSURE! The idea behind the inertial starter was to eliminate the weight of a battery, generator and starting motor.
The Bristol Sleeve Valve Aircraft Engine
An idea whose time may yet come, the Bristol sleeve valve radial engine was a reliable, powerful design that was built in large numbers during WW II. Instead of using poppet valves, the cylinder liner had ports in them. Moved by a linkage arm driven by a timing gear, the liners rose and fell, and rotated, to open and close the exhaust or intake ports. A “junk” head, with centrally located spark plug(s), allowed the cylinder liner to move both up and down, and to rotate. (Piston rings sealed the junk head from the moving liner.) In the eighteen cylinder Centaurus engine (the best ever made), a thundering 2,520 hp. was developed from 3,270 cubes with an overall weight of 2,695 lbs. And it did this while burning 10 % less fuel than conventional engines. See what I mean about potential? Without the scorching heat of the exhaust valves causing detonation, the sleeve valve design allows higher compression ratios. Their ideal, centrally located spark plug location is another plus.
The Pratt and Whitney R-4360 Radial Engine
Called the “corncob” because of it long, slim and bumpy shape, this 28 cylinder, 4 row, air-cooled radial engine was the largest radial engine to reach series production. How P & W managed to cool that last row of cylinders, with air that had already gone past three rows of hot cylinders—and make it work--was pure magic. Weight of this 4,360 cube monster was 3,600 lbs. Horsepower ratings ranged from 3,000 to 4,360
The B-36 used six of these motors. So complex was the starting drill that it took hours to get all of them running properly. Ditto for the shutdown sequence or heat would damage them severely—think of a subway train with square wheels and you get the idea. Engine analyzers were developed to keep all 168 cylinders running properly during the 10,000 mile missions these B-36s flew—a benefit we all now share. Finally, Howard Hughes’ famous “Spruce Goose” (that was made from birch plywood) used eight of these monsters.
Another idea whose time has yet to come is the turbo-compound engine. Imagine an engine with an exhaust-driven turbine, similar to that used in a turbocharger, that’s geared to the crank. At a steady, high power throttle setting, the energy normally wasted in the exhaust (or used to power a turbo) is used to add torque to the crankshaft. Before the arrival of hybrid automobiles this concept was impractical, for constant, high power settings are necessary to make it work. But in a hybrid, with the engine OFF, or running strongly to charge batteries (or make that hill) this concept makes sense for it would improve fuel economy significantly.
The most successful TC engine was the Curtis Wright R-3350 turbo-compound aircraft engine, a design that saw widespread use in airliners during the late piston engine era. Where as the “B-29” version of this engine made 2,200 horsepower, the TC version pumped out a thundering 3,700! And this was without a significant increase in weight or fuel consumption, for the normally wasted exhaust energy was now being used. Another TC engine was the little-known Allison V-1710, a V-12 design that produced nearly 3,000 hp. with water injection.
The Napier Nomad Diesel Aircraft Engine
One of the most ambitious aircraft engines ever built was this Napier design: a flat 12 cylinder, 2 stroke, diesel aircraft engine used a 3 stage, exhaust-driven turbine to provide both supercharging and a turbo-compound power boost. This incredibly complex, 71.1 liter monster produced over 3,000 hp. at 2,000 rpms (high for a diesel) while weighing a reasonable 3,600 lbs. The advent of turboprop engines spelled the doom of this ambitious design (to the relief of those who would have had to work on it). But it was truly something special.
The “Hyper” Aircraft Engines
The “Hyper” designation refers to late (ie; before jets took over) engines of very high output for their size and weight. One of the most interesting was the Napier Sabre II, an engine that was actually used in WW II. This was an “H” type engine with 24 relatively small cylinders arranged in four horizontal banks of 6 cylinders. (In essence, two flat twelves sitting atop each other.) With a bore and stroke of 5.0 x 4.75 inches, the cylinders were roughly the size of a “Rat Motor” (Chevy 454). This engine used sleeve valves instead of poppet-type valves, however, since they provided superior airflow over four valve heads. Displacement was 2,238 cubes for an output of up to 3,000 horsepower a relatively high 3,700 rpms while weighing only 2,500 lbs. The sound of a Sabre engine on take off was unique, to say the least.
An Assortment of Opposed Piston Engines
A Description of Opposed Piston Type Engines
This type of engine, usually a diesel, has two crankshafts geared to run together at each end of the engine block. Between the cranks are interconnecting cylinders that serve the function of combustion chamber and valves (via ports in the walls). Air comes in, and exhaust exits, through ports in the cylinder wall.
Several varieties of this engine are described below:
The Fairbanks Morse Engine
This upright, in-line, opposed piston engine was very successful in WW II American submarines. It was also used (less successfully) as a railroad engine after the war. One of the best sounding diesels ever made, it was built, with, identical cylinders, in 6, 8, 10 and 12 cylinder variations, with 2 pistons per cylinder.
The Navy, after its disappointment with the HOR engine (guess what they were called!), came to rely on the Fairbanks Morse OP engine, and it did not let them down. Regardless of the beatings they took, regardless of the extended TBO (overhaul intervals), these great engines ‘brought ‘em back’ every time, earning the respect of the submariners who counted on them.
Less sterling was the engine’s use in railroads. The exhaust-side piston, not being cooled by the Pacific Ocean, tended to run hot and seize. And, since the engine was a nightmare to fix, ‘dead’ locomotives sat there waiting to be fixed—lots of them. But she was a beauty in submarines!
The British Deltic Diesel Engine:
Built by Napier, who reveled in complexity, this fascinating engine was designed to produce maximum power in a compact shape. Three crankshafts, one at each apex of the triangle, operated 36 pistons, a the total of 18 cylinders—6 per bank. The three crankshafts were geared together at the output shaft. The result was a reliable 1,750 hp. in a smooth running, compact package. The major use of this engine was in British locomotives, where the engines gave reliable service. A version of the engine was installed in the “Nasty Class” boats used in Vietnam (lower photos of a "Nasty" being restored at Worton Creek Marina on the Chesapeake).
The Junker Jumo Aircraft Diesel
This opposed piston, six-cylinder aircraft diesel of up to 1,525 cubic inches produced roughly 1,050 hp. in a compact package that weighed only 1,300 lbs. Too underpowered for a successful military engine in WW II, it would have made a great airliner engine: reliable and stingy of fuel. By the time the war ended, however, the Junkers concern was rubble, and turboprop engines were on the horizon.
When the Luftwaffe (German air force) needed a very high altitude photo reconnaissance plane to spy on the British, an obsolete Junkers Ju 86 bomber was used. Equipped with heavily turbocharged Jumo diesels, a pressure cabin, and elongated wings, the aircraft was capable of amazing altitudes. It took a specialized version of the Spitfire V, with its pressure canopy sealed from the outside, to deal with the high altitude threat. Later versions of the Ju 86P, with higher boosted diesels and an even greater wingspan—fully 50 % greater than the fuselage length--reached an astounding 56,000 feet! This was higher than most of the early jet interceptors were capable of attaining.
A Few Railroad Diesel Engines
The Electromotive Railroad Diesel Engine Series
Produced in 8 to 20 cylinder versions, the EMD 2 stroke diesel is one of the most reliable, smooth running, long lasting, and easiest to repair engines ever built. This 45 degree angled, Vee-type engine has it been used in railroad locomotives, tugboats, ferries, stationary generators and a host of other uses. EMD even built an engine entirely from stainless steel to use in a minesweeper designed to sweep magnetic mines..
The EMD engine is a far more complex engine than one would expect, and it might surprise you to know how it operates: Four exhaust valves in the heads, operated by a camshaft, allow the exhaust to get out. Ports around the cylinders allow the fresh charge to enter, but how is the charge ‘sucked’ in? On a ‘normal’ two-stroke engine the crankcase performs this function. The EMD’s crankcase is filled with oil in the conventional fashion, however, so where does the air charge come from? A supercharger (or combination of supercharger/ turbo-charger arrangement on later engines. During cranking, and low speed running, a gear train powers the supercharger. At higher throttle the turbine wheel takes over automatically—very clever!) Another surprise is in the motor’s rod bearing design: Since the force pulling UP on the piston is minimal—the cylinder is either pressured by intake air or combustion—the bearing material on the bottom half of the rod bearing is minimal; a very strange sight to behold.
One other oddity (that’s common in locomotives) is the use of water only as a coolant; about 700 gallons of it. To prevent freezing, railroad diesels are never shut off in the winter. (They burn minimal fuel at idle speed.) For added protection a temperature sensor will ‘dump’ the coolant should the engine shutdown for any reason. Using that much glycol is an expense the railroads would rather avoid, and leaks into the oil would cause bearing problems.
A ‘dead cylinder’ means a locomotive out of service, so the EMD engine was designed from the outset for easy servicing. Each cylinder assembly—head, liner, piston, rocker arms, etc.—comes out the top after the removal of a minimum of bolts. (A cover in the crankcase allows one to disconnect the rod from the crank.) Drop in a new assembly and away you go!
Displacement per cylinder of these engines (and there are several variations over the years) runs up to 710 cubes per cylinder—that’s 14,200 cubic inches for a 20 cylinder model. The later 16 cylinder engines develop a reliable 4,000 hp at around 900 rpms with a weight of about 25 tons. All in all, an excellent design that has been updated successfully for lowered emissions and improved fuel economy.
The ALCO Railroad Diesel Engine
At first glance this 16 cylinder, 4 stroke diesel might seem rather ordinary. A closer inspection would reveal a unique feature of the later ALCO (American Locomotive Company) designs. The head used 4 valves per cylinder, a not-uncommon practice. What as truly unusual was that the valves were oriented IN-LINE instead of the usual practice of side-by-side. Air entering the cylinders could go into the first open intake valve, or slip past that one and enter the second one. Ditto for the exhaust gases exiting. Why ALCO did this is unknown (to me), but it worked, for the engines were powerful and reliable. Though ALCO went out of business, the engines are still built for various purposes, one of which is powering the Space Shuttle's launch platform crawler (with two engines).
Pleasure Boats with Twin Engine Installations
To reduce ‘prop walk’—a sideways force that swings the stern of a boat to one side (usually at an embarrassing moment, like when you’re docking with a crowd about)--props on some twin-engineed boats (such as this 32 foot Marinette) turn in opposite directions. How this is accomplished is not so simple: Either the marine reverse gear (transmission) has an extra set of gears to make the prop spin the other way, or the entire engine on one side turns ‘backasswards’ --as in this case.
To accomplish this neat little trick the camshaft gears that run the oil pump is reversed to turn it the other (ie; correct) way. The cam is ground ‘backwards’ to sequence the valves correctly. The distributor, which turns in the ‘normal direction’ off the oil pump, is set up differently to operate a reversed firing order. Of course the starter has to turn backwards, as does the water pump, alternator…Hell, why not reverse the prop through the transmission and get it the heck over with!
And Now, the World's Most Powerful Diesel Engine
The Wartsila-Sulzer RTA96-C turbocharged two-stroke diesel engine is the most powerful and most efficient prime mover in the world today. The Aioi Works of Japan's Diesel United, Ltd built the first engines and is where some of these pictures were taken.
Available in 6 through 14 cylinder versions, these inline engines are designed primarily for very large container ships. Ship owners like a single engine/single propeller design and the new generation of larger container ships needed a bigger engine to propel them.
The cylinder bore is just under 38" and the stroke is just over 98". Each cylinder displaces 111,143 cubic inches (1820 liters) and produces 7780 horsepower. Total displacement comes out to 1,556,002 cubic inches (25,480 liters) for the fourteen cylinder version.
Some facts on the 14 cylinder version:
Total engine weight: 2300 tons (The crankshaft alone weighs 300 tons.)
Length: 89 feet
Height: 44 feet
Maximum power: 108,920 hp at 102 rpm
Maximum torque: 5,608,312 lb/ft at 102rpm
Fuel consumption at maximum power is 0.278 lbs per hp per hour (Brake Specific Fuel Consumption). Fuel consumption at maximum economy is 0.260 lbs/hp/hour. At maximum economy the engine exceeds 50% thermal efficiency. That is, more than 50% of the energy in the fuel in converted to motion. For comparison, most automotive and small aircraft engines have BSFC figures in the 0.40-0.60 lbs/hp/hr range and 25-30% thermal efficiency range. Even at its most efficient power setting, the big 14 consumes 1,660 gallons of heavy fuel oil per hour.