V8 vs 4 cylinder, 1915 - 1923

[Rusty_OToole]

In an old article by Maurice Hendry I saw a quote from a conversation between W O Bentley and Henry Leland of Cadillac and Lincoln fame. It went something like this.

Bentley asked Leland why he built a V8, when he could get the same power and performance from a big 4 cylinder.

Leland replied, Mr Bentley you are a man after my own heart. But you are overlooking the fact that I can sell an 8 cylinder car where I couldn't sell a 4.

This may seem puzzling unless you know that the early V8s had a 4 cylinder type, 180 degree crankshaft. This meant that they had a secondary vibration similar to a 4 cylinder.

So why build a V8 if not for smoothness? I do know an eight of the same displacement, would have individual pistons and connecting rods half the size of a 4, which would affect the vibration and revs. Also, having another piston and rod at 90 degrees to the first, helps cancel out certain vibrations.

Basically that is all I have. Can anyone explain what advantages the early V8 had, to justify the complexity and expense, if not for more power and smoothness?

[CarlLaFong]

I believe it is, quite simply, the American idea that bigger is better. The average buyer, especially back then, didn't ask or care about vibration, rocking couple or the effects they had on the overall comfort or smoothness of the car. We're Americans. We want longer lower wider. Lots of flash and glitz. Would W.O. have built a 58 Olds or a 59 Cad?

[trimacar]

Agree with John, think it was just the time of experimentation, and why wouldn't more cylinders be better was the question being asked.

Not all V engines are smooth, however, there's a science to angles and degrees and ignition sequence and all those mysterious things that make an engine both operate and operate smoothly.

The V-8 would also give more power in a compact space, as straight eights take a lot of hood to cover.......

[Ivan Saxton]

What was the date of that alleged conversation between W.O. Bentley and H.M. Leland? Cadillac changed from its big four cylinder to its 314 cubic inch V8 around four or five years before Bentley became a manufacturer with his excellent four cylinder cars. A reminiscence of that period quoted by Maurice Hendry is significant. ( Attributed to W. O. Bentley by Maurice Hendry).

"During the 1914-1918 war I bought an open four-seater Cadillac V8. This was a very remarkable machine in many ways . . . one of the most flexible cars in top gear that I have ever driven, and astonishingly quiet. While some firms today boast that the passengers in their cars can hear only the clock at 100 mph, the only mechanical sound from the Cadillac at a very creditable top speed was its fan. I used to love to take it to Derby and, starting it in top gear, drive it at a slow walking pace round the Rolls-Royce works to show off its flexibility. This leg pull used to exasperate those present."

Leland largely overcame the annoyance of the vibration periods of the flat plane four throw crankshaft by making his Lincoln V8 with the cylinder blocks set at sixty degrees instead of ninety. Leland may well have learned that trick from the V8 version of the Liberty engine. I believe Wills St Clare used the same sixty degree angle for the blocks on his OHC V8. I guess that where Ferrari have made flat-plane V8 s, that induction considerations have outweighed the diminished vibration tendencies of a strong flat plane crank.

If a discussion of engine types did actually happen between Bentley and Leland, it more likely compared the water-cooled V12 with the large air-cooled Rotary. I guess the only way a Sopwith could whip around onto the tail of a Fokker in the direction not expected by the German pilot would be upside down, no doubt a manouvere in combat not recommended for the faint-hearted.

Edited March 31, 2014 by Ivan Saxton
onission of credit to Bentley for his quotation, ex Hendry (see edit history)

[Dandy Dave]

What was the date of that alleged conversation between W.O. Bentley and H.M. Leland? Cadillac changed from its big four cylinder to its 314 cubic inch V8 around four or five years before Bentley became a manufacturer with his excellent four cylinder cars. A reminiscence of that period quoted by Maurice Hendry is significant. ( Attributed to W. O. Bentley by Maurice Hendry).

"During the 1914-1918 war I bought an open four-seater Cadillac V8. This was a very remarkable machine in many ways . . . one of the most flexible cars in top gear that I have ever driven, and astonishingly quiet. While some firms today boast that the passengers in their cars can hear only the clock at 100 mph, the only mechanical sound from the Cadillac at a very creditable top speed was its fan. I used to love to take it to Derby and, starting it in top gear, drive it at a slow walking pace round the Rolls-Royce works to show off its flexibility. This leg pull used to exasperate those present."

Leland largely overcame the annoyance of the vibration periods of the flat plane four throw crankshaft by making his Lincoln V8 with the cylinder blocks set at sixty degrees instead of ninety. Leland may well have learned that trick from the V8 version of the Liberty engine. I believe Wills St Clare used the same sixty degree angle for the blocks on his OHC V8. I guess that where Ferrari have made flat-plane V8 s, that induction considerations have outweighed the diminished vibration tendencies of a strong flat plane crank.

If a discussion of engine types did actually happen between Bentley and Leland, it more likely compared the water-cooled V12 with the large air-cooled Rotary. I guess the only way a Sopwith could whip around onto the tail of a Fokker in the direction not expected by the German pilot would be upside down, no doubt a manouvere in combat not recommended for the faint-hearted.

Like!

[Ivan Saxton]

I beg your pardon. I was in too much hurry, and I have been corrected by my son Stirling, who knows detail and logic of modern cars far better than I.

The advantages for Ferrari in the flat plane crank are in even exhaust impulses in each bank, so the exhaust is more amenable to tuning. Inlet side is not an issue, and probably has fuel injection. Also, the flat crank is notably lighter for the same strength without the counterweights. The crankshaft requires less energy in acceleration due to lower rotational inertia.

For anyone who is not familiar with the concept of Rotary aircraft engines, the crankshaft is fixed and stationary in the aircraft, and the rest of the engine revolves around it. The larger the engine, the greater the rotational inertia and gyroscopic precession , and by the right-hand screw rule, the spinning engine wants the plane to turn, and to turn in one direction only. The second Bentley rotary was the biggest and heaviest rotary, so it had more of a mind of its own in dispute with the pilot. While some people liked to disparage the Liberty V12, it was designed, tested , and developed for military use in a very short time. It was adapted to mass production and was economical to produce. But the war ended before it could build a significant combat record.

[Dandy Dave]

I beg your pardon. I was in too much hurry, and I have been corrected by my son Stirling, who knows detail and logic of modern cars far better than I.

The advantages for Ferrari in the flat plane crank are in even exhaust impulses in each bank, so the exhaust is more amenable to tuning. Inlet side is not an issue, and probably has fuel injection. Also, the flat crank is notably lighter for the same strength without the counterweights. The crankshaft requires less energy in acceleration due to lower rotational inertia.

For anyone who is not familiar with the concept of Rotary aircraft engines, the crankshaft is fixed and stationary in the aircraft, and the rest of the engine revolves around it. The larger the engine, the greater the rotational inertia and gyroscopic precession , and by the right-hand screw rule, the spinning engine wants the plane to turn, and to turn in one direction only. The second Bentley rotary was the biggest and heaviest rotary, so it had more of a mind of its own in dispute with the pilot. While some people liked to disparage the Liberty V12, it was designed, tested , and developed for military use in a very short time. It was adapted to mass production and was economical to produce. But the war ended before it could build a significant combat record.

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[Rusty_OToole]

It is my understanding that Cadillac began making V8s in late 1914 for the 1915 sales season and Bentley began making cars in 1919. The first Lincoln was in 1921. The 90 degree crankshaft was not used until 1924. It was an innovation of the Packard straight eight which I believe was copied by makers of V8s.

You quote Bentley's impression of a Cadillac V8 bought during the 1914 - 1918 war, a time when thousands of Cadillacs were sent to Britain and Europe for use as staff cars by the US military.

I can't date the conversation which was from a book or magazine article of about 1972. But Leland did visit England in the early twenties and when he got back to Detroit read a paper at an SAE meeting, comparing auto manufacturing in England and the US.

The anecdote was most likely from a Ballantine history of Lincoln or Cadillac published in the early seventies. At one time I had nearly the whole auto and motorcycle collection and read them over and over.

All this is beside the point, which is, why did they make V8s if they had no advantage over a good 4 or 6 cylinder?

Edited March 31, 2014 by Rusty_OToole (see edit history)

[Matt Harwood]

Perhaps it was that eight (or more) cylinders were exclusive. EVERYONE had fours and sixes, but an eight was a big deal. My new expensive Cadillac had the same putt-putt-putt four-cylinder engine as your 3-year-old Model T. Bah!

The same was true of the twelves and sixteens that would follow--more was not necessarily better from an engineering standpoint (there are arguments to be made, but those magnificent machines weren't necessary for transportation purposes). Luxury cars were about image as well as engineering, and while the engineers were surely brilliant, selling cars wasn't an academic exercise but a profit-making venture. If you could differentiate your luxury car from the others with more cylinders, well, you did it. The Cadillac V16 doesn't exist because it worked better, it exists because, wow, holy cow, look at that thing! Pierce-Arrow had splendid sixes, but by the late-20s, it was obvious that shoppers in the Pierce-Arrow price class were choosing the competition with more cylinders despite there being no performance advantage, and Pierce went on to develop some wonderful eights and twelves.

The engineer in me says that more smaller cylinders work better than fewer big cylinders as there is more valve area and therefore better airflow through the engine, which makes more horsepower. However, given the primitive designs of the era, I doubt this was a consideration at the time.

Cars are vanity as much as transportation. The one you love says more about you than you'd think. Mine is bigger than yours, and all that...

[Dandy Dave]

Yes. I worked on an early V-8 Olds engine for a friend a number of years ago. Caddy had it before Olds. Dandy Dave!

[Guest prs519]

1 was thinking Owen Nacker's, et als, thoughts about more cylinders being better, particularly with luxury cars, derived from the fact that more smoothness, quietness, and perhaps especially, smooth starting torque, necessarily results from more, yet smaller impulses. As I recall (source long forgotten), one of the drawbacks to these multi-cylinder masterpieces was in harmonics, which tend to be set up at the consequent higher frequencies naturally occuring (per rpm, apparently). Can anyone add to my blasphemy? For those not knowing, Nacker was the guiding light in engineering the crankshafts, a very "smooth" engineer, indeed.

Also, can someone say why these multi-cylinder engines needed (necessarily?) such a relatively long stroke?

[Dandy Dave]

Basically, it was the thinking of the time. We went from steam engines with long strokes, to gas engines with a little shorter stroke. A lot of it has to do with the materials used at the time, and the splash type lubricating systems. A lot of early engines would not take RPMs of over 1,000 to 1,200 as a splash type system would sling the oil out instead of feeding it and keeping it in if one pushed the engines beyond there limits. Subsequently these engines were designed with a long stroke as it gave better torque at a lower RPM than we are use to in basic car engines of today. Better ideas and materials are introduce along with full pressure positive lubricating systems, the use of aluminum alloy pistons, better metallurgy for cranks and valves and other internal parts made it possible to shorten the stroke and increase the bore and RPM's. It all comes down to evolution. Dandy Dave!

[Guest]

Yes. I worked on an early V-8 Olds engine for a friend a number of years ago. Caddy had it before Olds. Dandy Dave!

What year would that engine be??

[Guest]

Basically, it was the thinking of the time. We went from steam engines with long strokes, to gas engines with a little shorter stroke. A lot of it has to do with the materials used at the time, and the splash type lubricating systems. A lot of early engines would not take RPMs of over 1,000 to 1,200 as a splash type system would sling the oil out instead of feeding it and keeping it in if one pushed the engines beyond there limits. Subsequently these engines were designed with a long stroke as it gave better torque at a lower RPM than we are use to in basic car engines of today. Better ideas and materials are introduce along with full pressure positive lubricating systems, the use of aluminum alloy pistons, better metallurgy for cranks and valves and other internal parts made it possible to shorten the stroke and increase the bore and RPM's. It all comes down to evolution. Dandy Dave!

Actually the big split ( popularity) was between electric cars and gasoline powered cars.

Chevrolet had no problems with scoopers for supplying oil to connecting rods right up until the fifties and those engines would turn as high as 4,000 rpm.

[Rusty_OToole]

Up to 1915 or so the "square" engine was the rule. Equal bore and stroke, or stroke a little longer like, 4" bore X 4 1/4" stroke.

Between 1910 and 1915 as cars became popular the quality of gasoline took a nose dive. From being highly volatile like naptha gas it became more oily like kerosene.

This is when "hot spots" "vaporizers" and long stroke engines began to show up. From 4X4 they went to 3X5 as a typical cylinder dimension.

The small bore allowed cylinders to be pushed closer together and so did one piece cylinder blocks as opposed to the older, pair cast cylinders. This in turn allowed shorter, stiffer crankshafts, and larger numbers of cylinders like inline 6 and 8 cylinder engines.

[bhambulldog]

What was the date of that alleged conversation between W.O. Bentley and H.M. Leland? Cadillac changed from its big four cylinder to its 314 cubic inch V8 around four or five years before Bentley became a manufacturer with his excellent four cylinder cars. A reminiscence of that period quoted by Maurice Hendry is significant. ( Attributed to W. O. Bentley by Maurice Hendry).

"During the 1914-1918 war I bought an open four-seater Cadillac V8. This was a very remarkable machine in many ways . . . one of the most flexible cars in top gear that I have ever driven, and astonishingly quiet. While some firms today boast that the passengers in their cars can hear only the clock at 100 mph, the only mechanical sound from the Cadillac at a very creditable top speed was its fan. I used to love to take it to Derby and, starting it in top gear, drive it at a slow walking pace round the Rolls-Royce works to show off its flexibility. This leg pull used to exasperate those present."

Leland largely overcame the annoyance of the vibration periods of the flat plane four throw crankshaft by making his Lincoln V8 with the cylinder blocks set at sixty degrees instead of ninety. Leland may well have learned that trick from the V8 version of the Liberty engine. I believe Wills St Clare used the same sixty degree angle for the blocks on his OHC V8. I guess that where Ferrari have made flat-plane V8 s, that induction considerations have outweighed the diminished vibration tendencies of a strong flat plane crank.

If a discussion of engine types did actually happen between Bentley and Leland, it more likely compared the water-cooled V12 with the large air-cooled Rotary. I guess the only way a Sopwith could whip around onto the tail of a Fokker in the direction not expected by the German pilot would be upside down, no doubt a manouvere in combat not recommended for the faint-hearted.

Would being upside down change the direction of the spinning engine?

Granted; with the airplane upside down, what was left is now right for the pilot in the upside down airplane.

But, the whip from the Sopwith's spinning engine would be in the same direction as viewed from the opposing airplane..

Edited April 6, 2014 by bhambulldog (see edit history)

[Dandy Dave]

What year would that engine be??

It was around 1916 if memory serves me correctly

[Dandy Dave]

Actually the big split ( popularity) was between electric cars and gasoline powered cars.

Chevrolet had no problems with scoopers for supplying oil to connecting rods right up until the fifties and those engines would turn as high as 4,000 rpm.

Yes. But we are discussing gas engines here. Yes. 4000 RPM's, How long could you hold them there with a load on the engine would be the question. A V8 from the 70's would typically be turning around 2,400 RPM while going 55 MPH. In high gear. Dandy Dave!

Edited April 6, 2014 by Dandy Dave (see edit history)

[Guest Magoo]

I would like to see the full Bentley quote in its context to see the degree of tongue-in-cheek that was employed. It's one thing to say that a decent four is perfectly acceptable for many uses. But in a fair match the four will never be as powerful or as smooth as the V8. It's a simple matter of physics.

Putting aside the balance issues for a moment, a four-stroke four fires every 180 crank degrees, delivering two firing impulses per crankshaft rotation. An even-fire V8 fires every 90 degrees, producing four impulses. The inline four will suffer huge torque reversals (over 100 percent of mean) as the crankshaft tries to start and stop twice per revolution. The V8 will supply much smoother torque delivery while requiring less flywheel mass, etc. And so eight are smoother than four, 12 are smoother than 8, 16 are smoother than 12, in diminishing returns as dictated by the application.

The balancing issues are also interesting and important...depending how far you want to drill down. It's not incredibly complicated, though it can be made so with a little effort. As mentioned earlier, Leland's Lincoln V8 used a flat (180 degree) crankshaft with a ~60 degree bank angle -- it's an odd fire engine, in other words -- which is an interesting approach. In a 90 degree V8 with a flat crank, the second-order shaking force works at right angles to the vector sum of the two banks, in other words horizontal to the ground and perpendicular to the crankshaft long CL. In the 60 degree block, the shaking force rotates at 2x crank speed. Leland likened the approach to soldiers breaking cadence over a foot bridge to dampen the swaying.

The problems (and solutions) of flat crank V8s and straight eights were understood for years before Packard introduced the 2-4-2 straight eight and Cadillac introduced the 90 degree crankshaft V8 in 1923. The issue was manufacturing difficulty/cost, as the solution required a multiple-strike crank forging. Until the times demanded the improvement in engine smoothness, it seems there wasn't sufficient justification to get it done. The Packard Single Eight and the improved Cadillac V8 came out within 90 days of each other.

[Dandy Dave]

Yes sir Magoo. Back to evolution, balance and harmonics.

[Rusty_OToole]

"Putting aside the balance issues for a moment, a four-stroke four fires every 180 crank degrees, delivering two firing impulses per crankshaft rotation. An even-fire V8 fires every 90 degrees, producing four impulses."

Before 1923 all V8s had a 180 degree, 4 cylinder type crankshaft. That was the whole point of the question. I would like to know, from a mathematical or theoretical standpoint, what advantage (if any) a V8 with 180 degree crankshaft, had over an inline 4 of the same size or horsepower with the same type crankshaft. I hope this is clear.

There are different factors that enter into it, such as the balance factor of having 2 rod and piston assemblies on each crank throw, working at 90 degrees. This would balance out certain forces. And the lighter weight of the individual pistons and rods.

I do know that a 180 crankshaft V8 is inferior in balance to one with crank throws at 90 degrees.

So the original question stands. How much of an improvement was a 180 crankshaft V8 over 4 of similar size and power? And why?

[Guest Magoo]

"Putting aside the balance issues for a moment, a four-stroke four fires every 180 crank degrees, delivering two firing impulses per crankshaft rotation. An even-fire V8 fires every 90 degrees, producing four impulses."

Before 1923 all V8s had a 180 degree, 4 cylinder type crankshaft. That was the whole point of the question. I would like to know, from a mathematical or theoretical standpoint, what advantage (if any) a V8 with 180 degree crankshaft, had over an inline 4 of the same size or horsepower with the same type crankshaft. I hope this is clear.

There are different factors that enter into it, such as the balance factor of having 2 rod and piston assemblies on each crank throw, working at 90 degrees. This would balance out certain forces. And the lighter weight of the individual pistons and rods.

I do know that a 180 crankshaft V8 is inferior in balance to one with crank throws at 90 degrees.

So the original question stands. How much of an improvement was a 180 crankshaft V8 over 4 of similar size and power? And why?

With a 90 degree bank angle, a V8 will fire once every 90 degrees with either a flat (180 degree) crank or a cruciform (90 degree) crank 4x per crank rotation and 8x per operating cycle.

So a Cadillac V8, say, of either 1915 (flat crank) or 1924 (90 degree crank) configuration will deliver four torque impulses per crank rotation -- twice as many as a four-stroke four. That part of the deal doesn't change.

With bank angles of other than 90 degrees (like the Leland Lincoln, Wills, etc) it's somewhat more complicated as uneven firing intervals are introduced -- but there are still eight torque impulses per operating cycle.

[Guest]

"Putting aside the balance issues for a moment, a four-stroke four fires every 180 crank degrees, delivering two firing impulses per crankshaft rotation. An even-fire V8 fires every 90 degrees, producing four impulses."

Before 1923 all V8s had a 180 degree, 4 cylinder type crankshaft. That was the whole point of the question. I would like to know, from a mathematical or theoretical standpoint, what advantage (if any) a V8 with 180 degree crankshaft, had over an inline 4 of the same size or horsepower with the same type crankshaft. I hope this is clear.

There are different factors that enter into it, such as the balance factor of having 2 rod and piston assemblies on each crank throw, working at 90 degrees. This would balance out certain forces. And the lighter weight of the individual pistons and rods.

I do know that a 180 crankshaft V8 is inferior in balance to one with crank throws at 90 degrees.

So the original question stands. How much of an improvement was a 180 crankshaft V8 over 4 of similar size and power? And why?

My summation would be not much. Evidence of this would be Oakland and Pontiac used a engine synchronizer to offset the power pulses on their 180 degree V-8 cranks.

Edited April 10, 2014 by helfen (see edit history)

[Guest prs519]

Thanks to the several great inputs to this subject. I am in danger of gettin some lernin. A couple questions: Regarding the tendency of the Sopwith to move in a preferred direction, wouldn't that be void, because the impetus would be rotational, and thus in the same direction irrespective of the positioning of the aircraft? However, upside down, the lift of the wing geometry would be pushing down rather than lifting up, so that the advantage of being upside down would be in the ability to dart downward quickly? Why would fixed-crank differ from fixed-cylinders, in this respect, or would they? Another unrelated question: are there no frictional considerations (costs), depending on the angle the (reciprocating) rod makes with the journal (and how much time it spends average at various angles (depending partly on block cast angle)? Wouldn't a shorter throw be a more efficient engine? I hope my questions makes sense enough to be answered, but it certainly understandable, if not. Not trying to hijack the original question, but the OQ took me here. Anyone? Ivan, where did you go?

[Guest Magoo]

I think the phrase about flat-crank V8s that trips people up is "two inline fours on a common crank." This is accurate but misleading, causing people to presume that pairs of cylinders fire at the same time. No, a flat crank V8 fires once every 90 degrees and 8x per cycle, just like a modern V8.

The difference is the firing sequence. The modern V8 with 90 degree crank has its two outboard throws twisted 90 degrees so the reciprocating forces of four cylinders are in opposition to the other four.

[ply33]

Thanks to the several great inputs to this subject. I am in danger of gettin some lernin. A couple questions: Regarding the tendency of the Sopwith to move in a preferred direction, wouldn't that be void, because the impetus would be rotational, and thus in the same direction irrespective of the positioning of the aircraft? However, upside down, the lift of the wing geometry would be pushing down rather than lifting up, so that the advantage of being upside down would be in the ability to dart downward quickly? Why would fixed-crank differ from fixed-cylinders, in this respect, or would they? . . .

I am not a pilot and my static and mechanics classes in college were many, many decades ago so I am far from an expert on this. But this is what I think:

The more rotating mass, the more like a gyroscope the engine acts like. And if the crank is fixed with the whole engine rotating there is a lot of mass. Spin a child's gyroscope and then press on the top in one direction you'll see they gyroscope will try to move in a direction that is 90° from where you push. Seems like that would make for some handling issues for an airplane. And that engine will be trying to spin the whole aircraft in the opposite axial direction than it is rotating so banking to one side would act quite differently than banking to the other.

[Dandy Dave]

Cole Palen Of the old Rhinebeck Aero Drome many years ago had rebuilt an early airplane with an engine that turned left handed. He is on tape (Cole Palen's Flying Circus.) saying he had concerns flying it for the fist time because the gyrations were opposite of the other planes that he was use to flying. Of course he did fly it and came back without incident. But he was never comfortable with it. Dandy Dave!

[Ivan Saxton]

Would being upside down change the direction of the spinning engine?

Granted; with the airplane upside down, what was left is now right for the pilot in the upside down airplane.

But, the whip from the Sopwith's spinning engine would be in the same direction as viewed from the opposing airplane..

That is quite correct, of course; and I made an hypothetical assumption without access to my old physics text books, which my eldest son took over a good many years ago. Upside down, the rotary-powered aeroplane would want to precess in the opposite direction for its pilot, but not for the enemy in pursuit.

To make sense or sequence for other loose ends, the following.

There were a number of V8 engines earlier than Cadillac, but it would be hard to ague that any of those approached the merit of Cadillac. Darraq built a huge V8 in 1925 for a racing car. The engine has survived, and a replica of the original car has been constructed around it in NZ, I think. They then made the first of the V8 road cars just before WW1, but few were apparently built till after the war.

De Dion Bouton made several different size V8s before that war; but they may not have been outstanding for performance and efficiency. One blunder was encasing the exhaust system inside the water jacket.

About 1907-8 Hewitt made a V8 in NY, which I think is shown in one of Stan Yost's books of oddities.

Rolls Royce built a wide-angle under-floor V8 engine car for slow and silent travel about town about 1905, but it had little popular appeal.

Another English car, Adams, made several different sizes of V8 prior to 1910, those most cars they built were four cylinders. One of the fours has survived and was restored at Geelong , here in Victoria; And there may have been a dealer there, because I saved a full set of conrods and pistons from a pile on the floor of Marwood McKenzie's wrecking yard . They are side-by-side rods, with 7/16" British Standard Fine thread conrod bolts. (The total engine displacement might be as much as 7 litres.)

You have to understand what the last of the 4 cylinder Cadillac engines were like to understand how much better the first V8s were. The 1912 cars were the first to have the self- starter and full electrics. The bore and stroke was 4 1/2"by 4 1/2" with separate copper -jacketed pots. They would rev out quite well, but they were really stationary engine technology, though the accuracy of their manufacturing was beyond reproach. But the splash oiling and the hinged conrod big-ends were primitive. For 1913 they increased the stroke to 5 3/4", which gave a lot more torque, but they would not pull revs like the 1912s. It did not help to have those very big valves heads when the hexagonal hole in the left-and right threaded nipples which held the cylinder heads onto the barrels was such a flow restriction. The two-speed diff of 1914 gave a satisfactory top speed, but the ratio of sprung to unsprung weight was insane. No wonder the V8s became immediately so popular. With the exception of a recession in 1921, yearly sales were mostly up around 20,000. The speed and accuracy with which they could mass-produce such high quality cars was amazing. Cadillac certainly built many more V8s per year than Bentley built fours and sixes in all the decade of their independence. I always had ambition to own a three litre Bentley, and obtained most of an incomplete 1923 engine in a trade deal. From memory, the engine number was 353. ( That engine enabled a friend to produced a superb restored 3 litre in conjunction with an assembly of parts he had obtained. Bill paid the price for my 1928 SPECIAL BB series DV32 Stutz prototype engine DV30004.) When I rode in that Bentley, I was very disappointed in the performance. I think you may have to alter them to make them really move. That does not mean that they are not a most desirable car to own and drive. Many years before, I was surprised that I had to drop my 1918 Mercer back into third to accelerate past a slow 3 litre Bentley on a day run near Canberra during the 1970 FIVA International Veteran and Vintage Rally. At the time I thought that Edna must have had a very repressive influence on George's driving. With single overhead camshaft and four valves per cylinder, Bentleys just do not go as you might expect. The mystery is that Bentley employed as engine designer F T Burgess, who was the designer of the 3.3 litre Tourist Trophy Humbers, which had very close similarity to Ernest Henri's 3 litre Peugeots. But Henri influence is not obvious in Bentley engines.

The vibration period of flat plane crank V8 engines was often ignored until closed bodies became fashionable. Closed bodies would resonate, and the additional vehicle mass would often mean that it took longer to accelerate through the vibration period. The split plane V8 crank suffered some handicap due to the considerable extra mass of the counterweights used to balance out the secondary forces.

Owen Nacker joined Cadillac from Marmon about 1926, and Ernest Seaholm considered him Cadillac's best engine designer. Cadillac used cast iron pistons into the early 1930s. I had a half set of new 30 thou oversize 452B V16 pistons, which came with some new old stock parts from Mr Johnson who used to be the Cadillac agent in Melbourne. ( I gave them to Bud Catlett in 1970 because there was no V16 here, and I thought Harrahs may have been able to use them.)

[Rusty_OToole]

You mention DeDion's blunder of running the exhaust through the water jackets, Ford made the same blunder 22 years later and continued making it for 22 more years. They said it had the advantage of quicker warmups and cooling and silencing the exhaust, and caused no trouble as long as the radiator was big enough. I notice no one else copied them.

My best guess is that a V8 with a 180 degree crankshaft would have a secondary vibration period similar to an inline 4, but smaller. Also a V8 should rev higher and produce more HP per cu in and also breathe better since it had twice as many valves.

In the sixties, and more recently, some racers have experimented with 180 degree crankshafts in V8s. They report that HP is higher, but vibration problems are far worse. It does make it easier to pair up the exhaust header pipes.

At the same time as the first V8s hit the market such notable sporting makes as Stutz stuck with the big 4 cylinder, but with a T head and 4 valves per cylinder, giving a breathing and HP advantage over a 2 valve per cylinder design and similar valve area to a V8.

Others found a straight six a better proposition for power and smoothness. From 1915 to 1923 the luxury car market seemed divided between the straight six and the V8, with the Packard V12 being an outlier.

Re: the Bentley 3 liter. Too bad you didn't read Those Bentley Days by A.F.C. Hillstead. He might have saved you wasting money on a Bentley. He was Bentley's first sales manager, starting before they made cars, when they were a DFP dealer. He described the 3 liter's performance as being similar to a 1953 Austin 30 or Morris Minor, with a top speed of 72 MPH.

A lot of people were disappointed with the 3 liter Bentley because for sheer speed it wasn't much different from its less technically complex contemporaries. It was more about miles covered in an hour, than miles per hour.

Edited April 10, 2014 by Rusty_OToole (see edit history)

[Dandy Dave]

An engine will only breathe better if it has sufficient intake and exhaust ports, manifolds, exhaust pipes, and mufflers to do so. Many early engines were restricted in the amount of air they could take in by the smallest part of the intake, and a restricted exhaust. Quite often the muffler outlets were restricted to reduce noise. Dandy Dave!

[Rusty_OToole]

You might also mention the lack of automatic transmissions. Working the clutch and gearshift was a trial for a lot of owners so car makers did everything they could to eliminate gear shifting. The best car was one that could be driven everywhere in high gear, idle down to a walking pace then pull away without knocking or bucking and climb any hill without down shifting.

The result was very detuned engines with mild cams, low compression, and restricted breathing. And very low rear axle gear ratios. This was OK as long as road conditions did not allow driving over 50 for more than a few miles.

[Guest prs519]

Wow, I must keep you guys going, lest your knowledge be lost! Thanks!! Am I correct to say that any engine could be said to have the same number of firing orders as it has cylinders, with only the starting point and end point sufficient to indicate the endpoint (or should I say, return to the same starting point)? Have any of you ever translated the firing order of two V8s with entirely different (appearing?) firing orders, so as to see if the physical location of successive power strokes of each cylinder is the same (irrespective of the arbitrary numbering arrangements, or rotational direction of the rotor)? If this were all sorted, might even the straight block engines follow a firing cycle equivalent to each other, insofar as relative physical location is concerned? I may have to get off my duff and figure this; I thought it might save me that effort and time to ask, as some, or all of you, may already know the answer. Knowing this for sure might help clear some clouds in my head regarding smoothness, especially when used with magoo's explanation and charts, which reveal a nicely tangible explanation of several aspects.

[ply33]

. . . Am I correct to say that any engine could be said to have the same number of firing orders as it has cylinders, with only the starting point and end point sufficient to indicate the endpoint (or should I say, return to the same starting point)?. . .

Haven't got a clue about V type engines but I did some thinking about inline 4 and 6 cylinder engines and basically given one direction of rotation there is only two reasonable fire orders for each.

Consider the inline 6 where #1 is the front cylinder: On a "sane" crank, the #1 and #6 cylinders are on the same throw (pistons up and the same time), #2 and #5 are on the same throw and #3 and #4 are on the same throw.

If we arbitrarily start with #1 firing and want to even the impulses from fore and aft we need to fire either #4 or #5 next. Once you decide that the rest is fixed. If you pick #5 (pretty common) then you can only follow that with #3 (#1 has fired this cycle, #2 is paired with #5 which has just fired and #4 is toward the rear). Now you've done 360 on the crank, 180 on the cam and you need to fire the paired cylinders in order which gives you #6, #2 and #4. Final result is 1-5-3-6-2-4 which is the order of a lot of 6 cylinder engines.

Once I figure this out and double checked with the manuals for my various cars, I never again worried about getting the spark plug wires on correctly. Simply visualizing the crank tells me what wires go where.

Edited April 10, 2014 by ply33 (see edit history)

[Dandy Dave]

Yes Sir. And the opposite rotation is 1-4-2-6-3-5. I have run into this on some 6 cylinders from the teens and twenty's. Dandy Dave!

[Guest prs519]

So -- Dandy Dave -- could I just as accurately claim that the firing order you stated is 426351 or 635142?, for exxample?? Not to whip a tired horse, but in the case of the v12s and V16s, wouldn't the firing BTDC interval have a significant bearing on the smoothness of the engine? Thanks, Ply33, for keeping the discussion down to Earth (on my part, anyway) and from beicoming too over-complicated with your clear explanations! I must throw out one more teaser, though. Would it be practical, particularly on a V16, to fire off each pair of counterbalancing cylinders at exactly the same time? This clearly would not work well with the rotational-block type engine! Am I wrong to wonder if tuning up a V16, that were out of time, with a few spark plug wires crossed, might be an exercise in hilarious frustration?!! Any of you ever had that experience?

Yes Sir. And the opposite rotation is 1-4-2-6-3-5. I have run into this on some 6 cylinders from the teens and twenty's. Dandy Dave!

Thanks, and I will try now to contemplate more, and type less! VERY interesting post. Edited April 11, 2014 by prs519
wrong word used (see edit history)

[Dandy Dave]

Move the numbers where you want. Start with what ever cylinder you want. As long as you continue with the correct order it will be right and run. Another way to think about it is if you are running a timing chain and the cam turns the same direction as the crank on a right hand straight 6 engine. Follow 1-5-3-6-2-4. Using the same configuration cam and turn it with a gear and now it turns the opposite direction of the crank. The firing order will be. 1-4-2-6-3-5. To put it simply, Put the 1 at the end of the 1-5-3-6-2-4 sequence and read it backward. The same crank will work either way.

Edited April 11, 2014 by Dandy Dave (see edit history)

[Guest prs519]

Rusty, I do not know if is the correct answer but it may be the shortest: Horsepower to weight ratio.

It is my understanding that Cadillac began making V8s in late 1914 for the 1915 sales season and Bentley began making cars in 1919. The first Lincoln was in 1921. The 90 degree crankshaft was not used until 1924. It was an innovation of the Packard straight eight which I believe was copied by makers of V8s.

You quote Bentley's impression of a Cadillac V8 bought during the 1914 - 1918 war, a time when thousands of Cadillacs were sent to Britain and Europe for use as staff cars by the US military.

I can't date the conversation which was from a book or magazine article of about 1972. But Leland did visit England in the early twenties and when he got back to Detroit read a paper at an SAE meeting, comparing auto manufacturing in England and the US.

The anecdote was most likely from a Ballantine history of Lincoln or Cadillac published in the early seventies. At one time I had nearly the whole auto and motorcycle collection and read them over and over.

All this is beside the point, which is, why did they make V8s if they had no advantage over a good 4 or 6 cylinder?