When Buick Built A V8 Engine With Infinite Torque – The Buick Nailhead
When Buick Built A V8 Engine With Infinite Torque – The Buick Nailhead
In the early 1950s, the American automobile was entering a new era.
The towering hoods and long engine bays of the 40s were giving way to lower, sleeker designs.
Styling was becoming more modern, more aggressive, and under those shrinking hoods, there was less room than ever before.
But the cars themselves were not getting smaller, they were also getting heavier.
So power was still paramount.
And for Buick, that created a crisis.
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Its trusted straight 8 fireball engine, which was a smooth, durable cornerstone of the brand, simply would not fit into the company’s new chassis that they were developing for a 1950s America.
The old engine architecture was too tall, too long, and was rooted in a pre-war philosophy that no longer matched what Buick was trying to build, and the competition in the engine marketplace was fierce.
Ford was at this time phasing out their legendary flathead and preparing their new modern YB block design.
Cadillac had just launched a powerful overhead valve V8 and Chevy’s small block revolution was just around the corner in the 50s which meant that Buick could not afford to be late to the party.
So the company handed their engine dilemma to engineer Joe Turle and his team tasking them with creating something entirely new.
And what they delivered in 1953 was more than a suitable replacement for the straight 8.
It was Buick’s first ever overhead valve V8 and it was called the nail head.
Before long, this new Buick motor would gain a reputation for being one of the most feared and capable torque monsters of an era.
And the engineering behind it was especially crazy.
Funny enough, Buick never actually liked the name nail head.
That was actually a name that gearheads came up with to describe the motor’s narrow vertical valves.
Buick called it the Fireball V8 or the Wildcat.
But despite their attempts to make those names stick, the nail head was the one that everybody referred to it by except on the official brochures.
Joe Turle worked with Cliff Studebaker, Verer P. Matthews, and a few others on this brand new engine design.
Now, they were all trying to work hard to solve this problem for Buick, and the solution that they came up with was something that worked way better than you might expect at first glance.
It was actually so much so of a surprise that Turtle and Matthews published a white paper on what they discovered at the start of 1953.
Buick was looking for a torquy motor, not a high- revving one.
And this focus on torque led Turle to design a symmetrical pent roof combustion chamber which was unusual compared to the more common wedge combustion chambers of the time.
To visualize the pent roof, imagine a crosssection of the boar as a rectangle.
The top of the combustion chamber is then a symmetrical isosles triangle sitting on top of the boar.
It kind of looks like a kid’s drawing of a house in the crosssection with the valves on one side of the roof and the spark plug at the peak.
The more common method was to use a wedge head where the triangle is longer along one side which provides more room for larger intakes and exhaust.
But the asymmetric combustion chamber which is that of a wedge head is less smooth and combustion is technically less efficient.
Another common configuration for the combustion chambers is the legendary Hemi, which differs from the nail head in that the intake and exhaust valves sit on different sides of the quote unquote roof, allowing for better air flow.
The quote unquote roof, as I mentioned earlier, is also rounded on a hemi.
With all those nuances aside, let’s get back to the nail head.
The nail head was designed with a very common 90° split between the two legs of the V paired with the 90° top angle of the pent roof meant that the valves on the nail head were flat and moved precisely up and down.
The long valve stems and wide flat valves looked like the heads of nails, hence the name nail head.
When the engine ran, those nails went up and down like nails being driven into a board.
When other engineers saw it, they called it the nail head.
And it became much more popular than anything Buick could come up with, much to their dismay and all the money they sunk into marketing the Wildcat and other names.
In 1953, Turle’s team debuted the most oversquare engine that you could get in a production car that year.
The first Buick nail head was a 322 cubic inch engine with a remarkable 4-in bore and 3.2 in stroke on a 4.75 in bore spacing.
At first, they worked with a unremarkable 8 1/2:1 compression ratio, but that was soon to vastly improve as the horsepower wars heated uP. The nail head saw a lot of modifications over those first few years as part of its teething process.
The major issue with the nail head design, although it was great, and it’s the reason that nobody else tried this kind of design, was simple.
It was air flow.
The nail head had the intake and exhaust manifolds on the same side of the cylinder, which meant that space was at a premium.
The valves on the original nail head were absurdly small since they had to sit next to each other.
The intakes were 1.75 in wide, and the exhaust valves were only 1.25 in wide.
Even worse, the manifolds leading into and out of the engine were ridiculously curvy.
The factory exhaust pipes made a near 180° turn right out of the valve.
This helped make the engine more compact, but it also restricted air flow at high RPMs and became a huge puzzle for various hot rodders of the day to try and solve.
But in classic hot rodder fashion, they would be able to pull it off, which we’ll dive into in just a moment.
The 322 cubic inch version of the nail head went into the larger wheelbase offerings from Buick from 1953 to 1956 in the Roadmaster, the Century, or the Super.
It was a solid, reliable engine that was perfect for street driving and represented a quantum leap from the straight eights.
The flat, plentiful torque curve meant that you could get a solid push forward when you needed it, no matter how fast you were going.
Over its three years of production, that 322 underwent various improvements and tweaks.
Later models had a compression ratio of 9 and a half to one and better Dynaflow carburetors that brought horsepower as high as 255 horsepower at 4,400 RPM thanks to a four-barrel carburetor and 341 ft-lbs of torque at 3200 RPM.
These numbers were very favorable compared to the 337 cubic inch Ford flathead jumbo V8 that was around at the same time, which only made 150 horsepower and 275 ft-lbs of torque.
It even compared well to the 312 YB block Ford that came out in 1956, which had its highest trim level at 235 horsepower.
The nail head even beat out the 265 cubic inch small block Chevy released in 1955 for the Corvette, even on a horsepower per cubic inch basis.
It even outperformed the famous Oldsmobile Rocket motor.
The only production V8 that could beat the nail head was the Cadillac motor of the time, and some have said the Cadillac specs were a bit more than a little bit exaggerated.
Nonetheless though, the nail head was capable of amazing torque and very good power in a much smaller package or pretty much anyone else made at the time.
Of course, Ford and Chrysler began to take notice and make serious improvements in their engines as well.
But the nail head had a great big head start.
And not only was the nail head a good bargain for power, its wide flat torque curve made it excellent for drag racing if they could fix those airflow probleMs. Hot rodders tried a myriad of different shapes of intakes and exhausts.
People tried different carburetor configurations, forced induction, pretty much anything that you could think of.
Heck, apparently one person even reversed the intake and exhaust ports and tried running the valves in opposite order to improve air flow.
While this was all happening, Buick continued to focus on streetable power.
They released a lowerbore economy version of the nail head for the Buick special in 1954 and 1955.
This was a 264 cubic inch motor with a 3.625 in bore.
It only made 188 horsepower and 256 ft-lbs of torque.
Now, in 1957 though, Buick released the series 2 nail head with larger ports and valves, as well as larger ratio rocker arms to get faster valve lift and better air flow.
The new intake and exhaust ports were 1.85 in and 1.5 in, respectively, which was a big jumP. The compression was increased to a base 9 1/2:1 with some options bringing that ratio up to 10:1.
At first, the only new series 2 nail head was a 364 cubic inch motor.
The bore was increased to 4.125 in and the stroke to 3.4 in.
All these improvements brought total power up to 250 to 300 horsepower depending on the option.
There was even a high-performance kit for the Buick Century in 1957 that bumped the power up to 330 horses at 4,800 RPM and 400 ft-lbs of torque at 3,200 RPM.
We were getting into serious power territory.
And it didn’t stop there.
In 1959, Buick released the new 401 cubic inch version of the nail head, which would show up in the Skyllock, Grand Sport, Sport Wagon, and Wildcat.
It was Buick’s original muscle car power plant, making up to 325 horsepower and a stump pulling 445 foot-p pounds of torque.
However, the biggest and baddest version of the nail head was the 425 cubic inch one.
These fitted with a dual quad Carter AFB carburetor could get you 360 horsepower and 465 ft-lbs of torque at just 2,800 RPM.
These numbers were massive.
By now, the nail head was well known as a serious power player, especially in drag racing.
Max Blowski drove his 401 nail headpowered Ode Yeller 2 race car to numerous victories, and it was actually extremely competitive in SECA racing.
Tommy Ivo was also a huge fan of the nail head and built several dragsters powered with them.
He even built some custom dragsters for exhibition purposes only.
One powered by two nail heads and another one powered by four.
That one he called the showboat because it wasn’t eligible for most large-scale competitive racing, but he would take it around the states and campaigning.
And now here’s probably the craziest area where the Buick nail head was used.
In 1966, Lheed released the iconic SR71 Blackbird skylane.
Now, of course, the nail head wasn’t directly attached to that super light, super high-tech jet, but the J58 jet engines that powered the Blackbird couldn’t start up on their own.
They needed a boost from an external engine to bring up their RPMs to a point where they could be self- sustaining.
The start cart that the Air Force used to start those jet engines was powered by Buick nail heads.
Two of which provided the 600 plus horsepower necessary to spin those jet engines up to 3200 RPM where they could start running on their own, which is definitely the most obscure application for the nail head, but one of the coolest.
By the end of 1966, the other automakers were starting to catch up in the torque department, and the nail head itself was reaching the end of the line.
Buick had already boarded out and improved air flow as much as they could on that original design.
The large displacement nail heads were starting to show reduced reliability as the bores got bigger and bigger, and hot rodders started to move on to some of the better revving motors, the Hemis, and some various Chevy options.
So, the nail head’s popularity was in deep decline.
Buick needed to move on.
They tried an all aluminum V8 design in 1961, but issues with durability convinced them to switch back to a cast iron block in 1964.
However, since the nail head was introduced in 1953, casting technology had come a long way, and Buick felt they needed a new engine.
So, in 1967, Buick created an allnew big block V8 to replace the nail head.
That engine would prove to be reliable and cost-effective, and they would continue to build that through 1976.
Between the years of 1953 and 1967, Buick built hundreds of thousands of nail head engines at minimum.
If you want a piece of awesome looking garage art, a nail head is one of the greatest engines for it.
And you can pick some of these up for like a thousand bucks nowadays, depending on which version.
The nail head was an incredibly innovative engine.
It beat its competitors in power, torque, and compactness, and it held on to that lead for several years.
It was a monster for its time, and it made some of those early ’60s Buick’s real stoplight monsters when people didn’t expect it.
Heck, it was even the starter for the SR71 Blackbird.
The nail head is an engine with a lot of history behind it and a huge fan base.
And even though Buick didn’t like the name, the nail head name has stuck for generations.
And that concludes our deep dive into the iconic Buick nail head motor.
