The era of straight eight engines

[pkhammer]

  Being the ignorant Ford guy that I am, I always assumed that when good ol' Henry came out with the flathead V8, he was on the cutting edge of the times. Maybe that holds true if only considering the low cost field. There just seems to be so much information out there touting the revolutionary V8 from Ford.

 

  In any case I was unaware until recently that many manufacturers were producing STRAIGHT eights long before 1932. I was even more blown away when reading recently about Duesenbergs. I had no idea that race bred, overhead cam engines such as was available in the Model J even existed at the time! This was obviously a high priced, very exotic automobile at the time.

 

  I went on the look at other straight eights produced at the time such as the Buick overhead valve, and flatheads available from Nash, Hupmobile, Terraplane and Pontiac. I suppose all of these were much lower production than the flathead Ford V8, but I just wonder how these stacked up with one another in the late twenties and early thirties and how they stacked up against the Ford flathead V8. Thoughts?

[Mike "Hubbie" Stearns]

IMO an in-line engine has more torque than a v block engine. Back in the day, cars were heavy and needed more torque than horsepower. Speed wasn’t a thing back then. When it comes to horsepower and torque, torque is what gets the job done and horsepower is how fast that work gets done. Mike

[Hemi Joel]

This is a great topic! There was so much going on back then by so many different manufacturers. Straight eights were available as you know in many configurations from Flathead to pushrod OHV to single and dual overhead cam. 

 

I'll start with the Duesenberg model J, as I have personally rebuilt one. It was incomparable, nothing else was in the same league. Besides the dual overhead cam, four valve per cylinder technology, everything else in it was of an extraordinarily high standard. The original Duesenberg Pistons were so light, even the modern Forged aluminum Pistons that are being sold as replacements today weigh 30% more. The aluminum I-beam rods were also very lightweight. Full pressure oiling with a full flow oil filter and a pressure adjustment that was externally accessible so you could open the hood and adjust it if need be. The oil goes through two separate screens before reaching the oil pump pickup sump, and oil drag on the crankshaft is reduced by a full length windage tray. The cast aluminum oil pan is finned on the outside and the inside to help cool the oil.

The fully machined, counter weighted, forged steel crankshaft was a work of art with every surface on it machined and gleaming like chrome. It also had two large vials bolted to the crankshaft that were 95% filled with mercury, acting as a very effective vibration damper and balancer. 

There is two separate timing chains, they are about 2 and 1/2 to 3 in wide. Each one is kept tight by automatic adjusters. The adjusters have a clock spring to apply tension, but there is also a series of latching pins arranged in a vernier configuration that prevents the adjuster from going backwards once the spring tension has advanced it a notch. 

It seems to have been assembled with each bolt hole being precision, reamed and tapped. If you take, for example the front cover or the cam covers and loosen the bolts, even take all of them out except two, you cannot wiggle the cover fore and aft or side to side. Everything is fitted with great precision. 

I could go on and on.

 

Edited 5 hours ago by Hemi Joel
Correcting autocorrect (see edit history)

[bryankazmer]

Ford generally was using trailing edge technology. The competition was using hydraulic brakes, independent front  suspension, insert bearings, hardened valve seats well before cheapo Henry

[bryankazmer]

There were a number of V8’s before WWI, including a 1902 patent. Ford’s expertise was in manufacturability - how to make an inexpensive version of things. Which is after all important

[bryankazmer]

15 minutes ago, Mike "Hubbie" Stearns said:

IMO an in-line engine has more torque than a v block engine. Back in the day, cars were heavy and needed more torque than horsepower. Speed wasn’t a thing back then. When it comes to horsepower and torque, torque is what gets the job done and horsepower is how fast that work gets done. Mike

Torque and smoothness favored the straight eight, especially with the typical 3 speed manual transmission of the time

[Rusty_OToole]

There were V8s before there were straight eights. The French DeDion Bouton concern had a V8 production model in 1910. In the US, there were a number of new V8s in 1915 including Cole 8, Cadillac, Peerless and others. By 1922 there were more than 20 V8 cars on the market. It was about that time the first straight eights debuted. I believe the Italian Isotta Fraschini was first in 1921 followed closely by Duesenberg, with Packard being the first major auto maker to bring out a straight eight, flathead of the type that became most popular for luxury cars until the early fifties.

 

There were certain technical problems with making such a long complicated engine block casting and with flexing of the long crankshaft. Then there was the problem of balance. The first straight eights had a crankshaft like 2, 4 cylinder engines put together. They had a 4 cylinder type secondary vibration problem. The solution was to make the crank pins at 90 degrees instead of 180, this resulted in a much smoother engine.

 

Once these problems were solved the straight eight became most popular, the only firms that continued to make V8s were ones who had committed to the design before 1923. In those days the V8 block was made up of 3 separate castings, 2 cylinder blocks and a separate crankcase. The problem of making a V8 block in a single casting was solved in 1930 or 31 by Viking, followed by Ford.

 

So why did Ford make a V8? Because Henry wanted it that way. He didn't like six cylinder engines, and his Lincoln used a V8, so he demanded his engineers come up with a simpler, cheaper V8 for Ford. It would have been easier to make a six like Chev or Plymouth and in fact, they did eventually, in 1941.

 

There was even a rival straight eight to the Ford V8 in the Hudson Terraplane. It sold for about the same money and the straight eight made 5 more horsepower. But it only lasted a short time before being replaced by a six.

 

There are other details to the story but this post is long enough as it is. I may chip in more details if it seems desirable.

[pkhammer]

  I don't want to make this a hot topic, but I wonder why I've not heard of hot rods being made from cars with straight eights. Maybe there were some speedsters with straight eights? I've seen a very few hot-rodded straight sixes, but never a straight eight. I would think just after WW2, there would've been a pretty good supply of them in wrecking yards, being 15-20 years after they were introduced. Perhaps just the sheer volume of Ford V8s in the wrecking yards as well as Ford coupes and roadsters were also lightweight compared to anything powered by a straight eight. Certainly a straight eight wouldn't physically fit into just any chassis either.

[wayne sheldon]

I type slow, and get interrupted often, so Rusty_OToole beat me to some of this.

 

What made Henry's V8 special was that it was the first major production single cast mono-block V8. All that in one package made it the first economically cheap V8 available to people of modest means. Other than the low cost (Henry's real specialty!), there "arguably" was nothing really special about Ford's V8.

Would it surprise you to know that a V8 was designed and built for automotive use before a straight 8? The idea was proposed and patented in Europe soon after 1900. A handful of V8 engines were installed and used in European automobiles before 1907, although many more V8s were even then being used in Speed boats and aeroplanes.

One of the first V8 engines built for use in an automobile in the United states was then installed in a specially built motorcycle frame for testing. I don't have the article in front of me, but Floyd Clymer mentioned it and had quite an article and photos about it in one of his books many years ago. If I recall correctly, it was a bit before 1910.

Cadillac is of course usually credited with the first production V8 engine in a production automobile, late in calendar year 1914 for the 1915 model year. More serious recent research suggests that Cole likely beat them to the punch. Certainly, Cadillac was not alone with their V8 engine in the mid 1910s.

 

I don't know just when the first industrial and marine straight 8s were built? However I know some were around about 1910 (I would suspect some earlier?). Automotive straight 8s didn't come around until about the late 1910s. First in racing specials, followed by exotic (by 1920 standards) sporting automobiles like Duesenberg.

 

 

Edited 2 hours ago by wayne sheldon
I hate leaving typos! (see edit history)

[alsancle]

Someone needs to explain to me why 385 cubes was the magic number for maximum size of a straight eight.  I can only think of 3 exceptions to this rule,  Duesenberg, Isotta and Mercedes.

 

I thought it had something to do with internal vibration but do not know for sure.

[Rusty_OToole]

Glen Curtis built an air cooled V8 aircraft engine in 1907 and tested it in a motorcycle frame. It set a speed record on Daytona Beach of over 100 MPH. V8 engines were widely used in aircraft during WW1.

 

There were a few straight eight hot rods, even more six cylinder especially Chev and GMC sixes. But Fords were by far the most popular simply because they were so common, cheap, and easy to hop up with aftermarket parts.

 

It is interesting to note that Ford V8s did not start to show up at the dry lakes until 1937. They had to be around for a few years before used ones got cheap enough for the hot rod kids to afford them.

 

In the meantime there was big time stock car racing using new model cars, often straight eights. In 1927 the championship came down to a contest between Stutz and Auburn, both straight eights of identical bore and stroke and 298 cu in. But otherwise they were totally different, the Stutz had an overhead cam engine and a much more sophisticated chassis and drive train BUT it weighed 700 pounds more than the Auburn, which had a conventional side valve Lycoming engine and conventional chassis. The speed trials were very close but the Stutz prevailed, by less than 2 mph. Also worth noting, the Stutz was a $5000 car and the Auburn a $1500 car.

[Rusty_OToole]

4 minutes ago, alsancle said:

Someone needs to explain to me why 385 cubes was the magic number for maximum size of a straight eight.  I can only think of 3 exceptions to this rule,  Duesenberg, Isotta and Mercedes.

 

I thought it had something to do with internal vibration but do not know for sure.

Probably had more to do with size and weight. As time went on horsepower and performance increased while displacement stayed the same or went down. I'm sure we all thrill to the thought of a Duesenberg or senior Packard or Pierce Arrow but in practical terms, probably would have been happier with a smaller car.

[alsancle]

19 minutes ago, Rusty_OToole said:

Probably had more to do with size and weight. As time went on horsepower and performance increased while displacement stayed the same or went down. I'm sure we all thrill to the thought of a Duesenberg or senior Packard or Pierce Arrow but in practical terms, probably would have been happier with a smaller car.

No,  I think there is a real engineering reason for it.  I just don't remember what it is.

[prewarnut]

There's always exceptions. I found on-line the only surviving Leyland-eight produced with straight 8's of either 422 or 443.3 c.i.

 

[Steve_Mack_CT]

One issue with straight 8s is keeping the back end of the engine cool.

 

In terms of hot rods Greg, I suspect a few factors:

 

Before the Ford V8 hop up parts for the A& T flathead made making hop up stuff for the V8 a natural extension for those providers of Speed stuff.

 

The Ford V-8 was cheap to produce, relatively light & simple.  Soon there was a decent supply of them in junk yards.

 

For similar reasons traditional hot rods have been largely Ford roadsters and coupes.  While other v8s found their way into those cars a straight 8 in an A wouldn't be practical.

 

All obvious but just some thought as relates to Greg's comments.

 

For some reason when I think straight 8 I think locomotive like and when I think of Ford flat 8 and postwar ovh v8s I think more about a hot street car..

 

Cool thread for sure!

Edited 2 hours ago by Steve_Mack_CT (see edit history)

[wayne sheldon]

The rule is, that there is always an exception to the rule. Somewhere, there is a rule for which there is no exception. But I have not found it yet.

[edinmass]

Straight eight engines have several flaws……crankshaft whip is one major issue. The big engines use 9 main bearings………and tend to be the only ones that will take a real pounding. Believe it or not the mono-block straight eight is subject to flexing and failure at high horsepower output and loads……..if you spinning them fast with high output, the blocks will crack……….yes, I have seen this in person. You can only make so much power out of them before they fail. Power to weight ratio is another issue. Build it tough enough to make real power…….and it will weigh a ton.

Edited 2 hours ago by edinmass (see edit history)

[Rusty_OToole]

In relation to Ed's comments. If you look at a postwar Packard straight eight it has a pattern of squares cast into the block just above the pan rail. This was not decorative, it was added to stiffen the block and eliminate the kind of vibration he was talking about.

 

Every piece of metal will ring or resonate at a certain frequency. The longer the crankshaft the lower the speed at which this becomes a problem. Straight eights and sixes often needed a vibration dampener to prevent the crank from breaking, usually not  a problem with 4s or V8s because the crank was so short the vibration frequency was above the normal speed of the engine.

[Pfeil]

3 hours ago, Rusty_OToole said:

There were V8s before there were straight eights. The French DeDion Bouton concern had a V8 production model in 1910. In the US, there were a number of new V8s in 1915 including Cole 8, Cadillac, Peerless and others. By 1922 there were more than 20 V8 cars on the market. It was about that time the first straight eights debuted. I believe the Italian Isotta Fraschini was first in 1921 followed closely by Duesenberg, with Packard being the first major auto maker to bring out a straight eight, flathead of the type that became most popular for luxury cars until the early fifties.

 

There were certain technical problems with making such a long complicated engine block casting and with flexing of the long crankshaft. Then there was the problem of balance. The first straight eights had a crankshaft like 2, 4 cylinder engines put together. They had a 4 cylinder type secondary vibration problem. The solution was to make the crank pins at 90 degrees instead of 180, this resulted in a much smoother engine.

 

Once these problems were solved the straight eight became most popular, the only firms that continued to make V8s were ones who had committed to the design before 1923. In those days the V8 block was made up of 3 separate castings, 2 cylinder blocks and a separate crankcase. The problem of making a V8 block in a single casting was solved in 1930 or 31 by Viking, followed by Ford.

 

So why did Ford make a V8? Because Henry wanted it that way. He didn't like six cylinder engines, and his Lincoln used a V8, so he demanded his engineers come up with a simpler, cheaper V8 for Ford. It would have been easier to make a six like Chev or Plymouth and in fact, they did eventually, in 1941.

 

There was even a rival straight eight to the Ford V8 in the Hudson Terraplane. It sold for about the same money and the straight eight made 5 more horsepower. But it only lasted a short time before being replaced by a six.

 

There are other details to the story but this post is long enough as it is. I may chip in more details if it seems desirable.

Oakland/Pontiac V-8 1930-32 = single casting, Valves in the block with a block/head mating of two different angles so the valves are overhead of the piston.

 

Pontiac discarded this engine for 1933-1954 preferring a straight eight,