(first posted 3/20/2011. Updated 1/5/2021) Nailhead: what did Buick do to deserve that less than flattering name for its legendary V8 engine from the mid-fifties to the mid sixties? Hemi-head; even flathead are much more lyrical. For those not familiar with Buick’s unusual valve arrangement, we’ll do a primer on that, as well as touch on its brief glory days on the drag strip. But for those already enlightened on the subject, I offer something more: the source and likely explanation of its unusual valve arrangement.
Buick came late to the OHV V8 game, Cadillac and Olds both having introduced their superb engines in 1949. Buick’s venerable straight eight from the thirties at least had overhead valves, unlike the previous Cadillac and Olds flathead engines. That allowed it to stay in the post war game a bit longer with higher compression and multiple carburation. But it was heavy, and not at all suitable for the horsepower war of the fifties that was quickly developing.
In 1953, Buick brought out their new V8, with a very large 4″ bore and quite short 3.2″ stroke, the most oversquare engine on the market at that time. It displaced 322 cubic inches (5.3 L), and came in 164 to 188 hp variants. In 1954, a small-bore version with 264 CID (4.3 L) reserved for the low end Special arrived.
The new Buick V8 was relatively light and compact for its time, weighing some 625 lbs. It was built with high quality components, and quickly caught the eye of hot rodders, this being a few years before the Chevy small block came on the market. Its unusual head and valve arrangement made it a narrow engine, increasing its appeal to engine swappers, like this one replacing the six in an old Chevy. But it was precisely that narrow head that also presented serious challenges.
Here’s a nice cutaway of the Buick nailhead engine. What instantly stands out is the unusual arrangement of the valves and valve train, in that they hang vertically in a pent-head or almost hemi-head combustion chamber. We’ll discuss the origins of this later, but note how tortured the exhaust port is, having to make an almost 180 degree bend right behind its valve.
Just for comparison sake, here’s a cross section of the Cadillac V8 that preceded the Buick by two years. The bigger valves have a mild angle in relation to the head, creating a more typical wedge head combustion chamber. The ports are bigger and smoother, especially the exhaust. Perhaps the most obvious thing about the Buick nailhead is that its arrangement demands very small valves, which seems antithetical to the whole concept of the modern V8 in the first place.
Small they were, hence the “nail head” moniker. The early engines had a 1.75″ intake and a 1.25″ exhaust valve, puny even for the mid fifties. Even the legendary Wildcat 401 from the mid sixties had only a 1.875″ intake and a 1.5″ exhaust; both substantially smaller than the much smaller Chevy V8 engine.
The explanation generally given is that Buick was focusing on torque rather than maximum breathing at high rpm. And the Buick engines delivered that in spades, typically with more than one ft. lb. per cubic inch, a very respectable output indeed. In the sixties, Buick labeled and advertised their engines on their torque output, not the horsepower, which can be confusing. This Wildcat 445 is a 401 from a 1966 Skylark GS with 325 hp.
But Buick had to use very aggressive camshafts in order to make the nailhead work. By opening the little valves early, and very quickly, much of their limitations were overcome, up to a point. Already the first 322 nailhead had a camshaft that was the equivalent of a “super race cam” at the time; one that would be typically installed from an aftermarket supplier. The intake duration was 282 degrees, and the exhaust 292 degrees, with a 67 degree overlap, along with very steep ramps for extra rapid valve opening.
The camshaft in the 401s were even more aggressive, and those engines were known for their lumpy idle. Not exactly the image Buick typically was trying to convey at the times, with a banker’s Electra 225.
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Wild, man. I know the whole “rat rod” thing is kinda played out but I’d love a 1950s Roadmaster rat rodded out with nailhead power, although I wouldn’t attach it to a “Dyna-sloooooooooow” transmission.
Love that pic of Tommy Ivo, wearing a bow tie and looking like a model citizen. I’d love to see today’s racers still dressed like that when not behind the wheel of their cars.
“Love that pic of Tommy Ivo, wearing a bow tie and looking like a model citizen. I’d love to see today’s racers still dressed like that when not behind the wheel of their cars.”
That is pretty awesome, Kinda like when you look back at old adverts for work trucks and the driver has a full uniform on.
Some of us do dress like that when we’re not racing or working on cars… Many of todays youth have lost touch with something called class.
.. they learned that poor behavior from their parents.
In the old days, factory workers all wore suits and ties… it’s just what everyone wore…
Lol .You’re not into the jeans too big so the underwear shows?
MY DAD HAD A 51′ BUICK AVEC DYNAFLOW . I REMEMBER THE ENGINE RACING IN OUR DRIVEWAY WITH THE CAR BARELY MOVING FORWARD .
I know nobody will want to hear this, but driven properly the Twin Turbine Dynaflow gives astounding performance. By “properly” I mean manually selecting Low up to about 4000 RPM then shifting into Drive. The “Flip Pitch” linkage must be adjusted properly adjusted also. As you may know the Flip Pitch feature give the torque converter two stall ratios. And the Twin Turbine with two stators were used in the ’56 thru 63 model years. In 1975 I beat a ’67 SS 396 my 63 LeSabre 401 550 cfm 2 barrel Rochester in a quarter mile on $3 to Watch or Race Night. The only problem was getting enough traction for the 7153 ft/lb of torque on the rear axles.
The twin turbine Dynaflow was a good transmission if you manually used low gear. That transmission did not automatically start off in low; thus, by manually using low gear you could increase the power to the rear wheels by 43 percent. This was a huge power increase by just using low gear. My dad had a 63 225 sport sedan with the 401 dynaflow. He use to say low gear all the way. He would manually use low gear up to 65-70 MPH with a 3:23 rear end and then shift into drive. With cheater slicks he would turn a 15.2 1/4 @ 88 to 89 MPH. However, a lot of races were lost because people do not know you have to manually use low gear with the dynaflow. I saw a guy in a 425 63 Riv. flooring his Buick off the line in drive with just a tire chip; he did not know that you need to use low gear manually. You can increase your power by 43 percent in low gear. Moreover, most test times listed are using the dynaflow are done in drive-that is why the 1/4 performance is so lousy. If they used low gear it would be a lot better at least 43 percent better. Auto-catalog list the 1963 225 at 16.9 in the 1/4 mile and if you look at the small print it tells you that they use drive gear only. This is not a true test of what the Dynaflow Buicks will really do performance wise.
In theory, there are four ratios available with a “switch pitch” dynaflow- low range, low and high stator blade angle, high range, low and high stator blade angle. By the way, I find it somewhat amusing that racing torque converter companies are “rediscovering” the bolt-together torque converter. I had an argument with Art Carr, a racing automatic transmission manufacturing guy about this several years ago. He said that bolt-together torque converters of the past were too heavy, etc.. I think that the main argument was that they were too expensive to produce, and that most garden variety loser-lunkhead mechanics couldn’t keep them from leaking. It seems that what was old has become new again!
I agree by using lo gear it was much faster than taking off in drive with the dynoflo
Absolutely correct Glen. Us kids learned real quick about “low gear “. It had no effect on all the other cars except holding low to a higher speed. But a Dynaflow? Oh Boy! I was passenger in a 1/4 mile drag race between a 63 Buick LeSabre 401 2bbl.carb. and a 63 Chevy SS 327 – 300 hp powerglide. The Buick Dynaflow blew that SS away from the start. We had maybe 3 car lengths lead all the way to the shift to drive. Then the Chevy with it’s 300hp. finally caught up and passed us but just barely.
Absolutely! I drove my late grandmothers 63 Electra with the 401 and last year Dynaflow and that was a great running combo!
I love the old Buick’s from the 60s. I also like the twin dynaflow. You just have to know how to drive it using low gear. I won a lot of races with dad’s big Buick.
How do you adjust the flip pitch linkage? I had my 1955 Roadmaster dynafkow rebuilt and the mechanic must have misadjusted the flip pitch linkage because now it thumps hard when shifting from low gear to drive. Is it necessary to remove the transmission to make this adjustment? Is it an external adjustment? Do you have photos of this linkage? I have the Buick shop manual.
The unidentified engine looks like a Y block Ford. (Guess not :D)
A friend of mine had a 63 Riv with the 401. He nearly drove himself nuts trying to get to idle smooth because a “mechanic” told him it should. This eventually resulted in a replacement engine.
The only drawback I could ever see in that car was the Super Turbine 400.. What a PIG. That mill could have made 800 ft/lb of torque, it would all get sopped up in that trans.
Sorry; I decided this wasn’t quite the place for a guessing game. It’s an AMC, just because it was convenient.
Actually there was a rumor that the AMC V8 had it’s roots on the drafting board at Buick. Starting with the large displacement 430, Engineers made a lightweight design for it and it prevailed. Buick kept it and expanded. But they had another design much like Pontiac that was versatile with its’ displacement potential. That was farmed out to AMC after they ditched International Harvester as the engine block foundry. The main difference was the location of the distributor. Which Buick had intended for the front of the block. AMC got that as well and had a major 3 foundry produce the required engine blocks.
I doubt that it was a SuperTurbine 400. The ’63 still had a Dynaflow, the ST400 didn’t come out until ’64
Hi I am wondering if a 430 buick motor will fit in a 63 Electra 4 dr? Thanks
If it is a ’63 Riv it had Twin Turbine Dynaflow, not the ST400.
AMC? Cutting engineering there…
Good article, Paul. Any insight as to why Buick power kept appearing in more industrial applications – such as the Flxible bus line, and later, the whole Kaiser Jeep lineup? I’m sure cost and excess manufacturing capacity had something to do with it; but was there more?
Actually, the 304/343/401 AMC was a perfectly decent engine for its day; no?
The nailhead’s excellent torque curve and the use of high quality components, I have to assume.
True, that…the AMC V8s were state of the art when conceived.
You’ve probably heard the story of how they came to be: That Kaiser-Frasier had a V8 project, in the person of a single designer, with the project well along when Bank of America, their primary lender, pulled the plug on any additional credit against their losses. They dismissed most of the passenger-car people, sold the tooling to Argentina, and focused on their recent purchase, Willys.
That V8 designer, the name escapes me, was hired by the nascent American Motors…to (surprise!) design a V8 – which he had completed in “record time.” So…the AMC V8 was actually a Kaiser…long before the whole of AMC was the remnants of Kaiser Jeep.
I think you’re talking about the old AMC V8 from the fifties? This is the the one that came out in mid sixties.
I must agree on both points here…..A.M.C. did have fine motors as was the buick nail head, nail heads were easy to work on ‘
Indeed the AMC small-block V8 was as modern and durable as any small-block, introduced in 19661/2 as a 290, then 343, then 390, which each expanded to 304, 360, and 401. The 360 was used in big Jeeps right up to 1989. 390’s and 401’s had forged cranks and rods. International used the 401 in trucks and Travelalls.
I ran 343 engines in stock and super stock AMC Americans. Loved them. Ran 8000 RPM through the traps with 5.43 gears in the Super stock version.
Hmmmmmmmm well the buses couldn’t of required narrow engines, although the buckets of torque were likely a good thing in the bus builder’s mind. I once drove a U-hall across country (24 ft box) powered by a HD 350SBC and a three speed auto. I likely would have had an easier time with a Nailhead under the hood.
Strictly speaking, the Flxible Clipper used the old Buick straight eight. The Blue Bird bus CC has a nailhead, but I can’t absolutely assure it is the original engine. But Buick engines had a good rep for being rugged, and that would make it appealing for a bus operator.
So, as I get it, it’s the equivalent of a SOHC/DOHC arrangement? But for overhead valve pushrods? Interesting, one learns something everyday. It seems the engine was designed for double overhead valves, but they had to do with a single, and that’s why it was so narrow. Do you know why, and what happened? Are there more examples of quad cam pushrods? I always thoght that was an exclusive OHC arrangement.
“Are there more examples of quad cam pushrods? ”
Are you referring to the LeSabre/XP 300 engine? I’m not sure what you mean.
There were other ways to do a hemi-head pushrod engine than that arrangement for sure. The Bristol/nee BMW 328 design was one elegant solution, but I can’t find an image. And the Chrysler used the more typical approach:
I’m not really sure what I mean either. What I’m getting at is that the XP300 engine looks like a DOHC engine, though it’s overhead valve, pushrods and rocker arms. Both cylinder banks has two rows of valves. And the nailhead looks like it was designed like that from the start, with one of each rows deleted. Like designing a DOHC engine from start, then switching to SOHC along the way. My question was, are there similar pushrod engines where each cylinder bank has two rows of valves each? And I guess the Chrysler Hemi was the answer to that question. I was just curious, that’s all…
You have a DS, right? It has a pushrod hemi head, like so many other Citroens, from the 2CV to the DS. Peugeots did too; etc.They all pretty much are similar in arrangement to the Chrysler hemi, which was of course just copying long-established European tradition.
There were also lots of SOHC hemi engines; the BMWs being typical of the breed. They simply used rockers from the cam mounted between the two valves to actuate them instead of pushrods or two individual cams directly over each bank of valves.
What makes the LeSabre/XP 300 engine unique is that the pushrods come up through the block at that angle; never seen that anywhere else before.
Yes, I have a DS. Technically, it’s a DSpecial, the successor to the ID, the cheapo variant of the DS. It’s a 1975, one of the very last, they only made a couple of hundred that year. But yes, I forgot about that one. It didn’t cross my mind, as in my mind, virtually all straight fours in recently modern times were pushrod hemis, at least up until the 80’s. I just got so tangled up in my mind about V-engines in this thread.
For budgetary reasons, Citroen couldn’t afford a new engine for the DS. But they designed a new cross flow hemi head to the old traction avant engine. If I am to be totally honest, I have actually no clue whatsoever to how that really looks like technically. I have to check it out. You don’t really buy a Citroen for the engine.
Though, I dream of substituting that for a Corvair six. Or perhaps the complete drivetrain from a Prius. The Citroen freaks usually say you could run the entire car from the generator that pumps up the pressure for the hydraulic system. And that really isn’t that far from having an EV or hybrid engine run the complete car entirely.
The flathead Lycoming V8 in the prewar Cord had valves operating where you find the horizontal pushrods of the Buick experimental Le Sabre. I think I have its crossection somewhere.
I see a center mounted cam in there….No S.O.C.K. or D.O.C.K. here as I’ve worked on the 427 Ford SOCKs
The Riley four was a twin cam pushrod engine mounted very high on either side of the block to give a hemi-head, one of the first infact.
The ultimate development of this engine was a V8 fitted to the Riley Autovia. In this configuration it used three cams, one shared inlet at the centre of the ‘V’ and two outside cams controlling the exhaust.
Here is a picture of one:
It may look like a DOHC, but they are rocker covers.
Thanks. You joggled some very dormant and faint memories with that. I love the creative and unique solutions engineers used to come up with.
Harley-Davidson Sportster V-Twin engine has always been a quad-cam push rod design. 4 gear-driven cams. One per push rod.
Let’s not forget the most unique application of Buick power: twin Nailheads powered the AG330 start cart, which fired up the big Pratt & Whitney J58s on the SR-71 Blackbird via a vertical driveshaft.
Nice pic of one, I see what you mean, that’s definitely a nailhead.
Seeing one of those things in person (at Seattle’s Museum of Flight) checked off a box in my lifetime To Do list. Unfortunately, I’ll probably never get to check off the box next to “Hear a start cart running at wide open throttle.”
That would still pale next to hearing the SR-71 at full throttle 🙂
I’m somewhat familiar to the SR-71 AG330 start carts – the ones used when I was stationed at Beale AFB 1969-1973. They were twin Buick 455’s linked by a torque converter and connected to the J-58’s via a very large, flexible drive shaft. Full open headers and little else. What a sweet sound (racket to some) they made – they sounded like you were at a drag race! You had to spin those J-58’s to a certain rpm until the “fire” – THB – would catch the JP7 and ignition would occur at around 3,200 rpm. Miles away in my barracks room, when a Blackbird was at the engine pad being worked on, at full throttle, you’d swear a Saturn V bound for the moon was taking off! Ahhh…memories…
I wonder how many folks have ever heard a J-58 in “hypersonic” mode, outside of maybe wind-tunnel testers & flight crew. For obvious reasons, SR’s flew relatively slowly at airshows, where I saw/heard one, & that’s where it runs as a turbojet. I think even the B1 was louder. Still, pretty amazing flight envelope there.
Crazy thing is, SR-71s were said to be more efficient the faster they flew. If only cars could be that way!
Never had the pleasure of hearing the SR, but I WILL tell you about being in the Seabees and working at the end of the runway at Danang AFB when those bastids in their F-4 Phantoms would take off and right at the end of the runway, hit full AB and take off straight up, probably laughing at us schmucks back on the ground!
(Heh, what did you say?)
It may not be the best performance-wise, but a dressed-up multi-carb Nailhead is a beautiful looking engine.
Thanks for this wonderful article. I just love old Buicks . That reversed-port blown engine in the rail is really clever.
A common trick for sidevalve Ford 4s was to reverse the manifolds using a gear driven cam as opposed to chain driven it gives those little heaps great power for boats
Of course one mustn’t forget the Rover V8 which is another variant and of course directly related to the 215 (to call it an ex-Buick engine does a great disservice to Rover engineers who basically redesigned almost every feature of the engine as a result of having far more aluminium casting experience).
The Oldsmobile 215 is also the only American designed engine (at least the block) to win the F1 world championship, notwithstanding it had OHC (eventually DOHC).
Repco of OZ also redesigned the Buick engine for formula one ever heard of Jack Brabham
Rover employed Joe Turlay, a retired Buick engineer (got to keep his GM pension), & he saved them tons of man-hrs pointing out off-blueprint design changes.
This is not to take away from Rover’s diligence & success in later development.
Glad someone mentioned the start cart, one is on display on the Intrepid flight deck right next to the SR-71 it was designed to start. As for the Corvair-powered DS, wasn’t that car originally designed for a flat-6? Wouldn’t be too much of a reach then.
Buick and GM have taken plenty of heat for letting the aluminum V8 go, but they really didn’t, as the second-gen V8 was basically a cast-iron development of the same engine. And it was comparable in weight to a small-block Chevy, even as a 455.
Thought I typed in a sentence about Cord Lycoming V8 having its flathead configuraton with similar high central camshaft for horizontal valves. If
this flies maybe I will try sticking a pic of its crossection .
I can’t remember the source, but the reason for the narrow engine, and in turn the vertical valves, was that Buick was caught with its pants down by the ’49 Olds and Caddy OHV V8s. Buick realized it needed a V8, if for nothing more than image, but couldn’t fit the wide Olds or Caddy engines between its front suspension towers, hence the narrow Nailhead.
For Tommy Ivo, image was an important component of what he was selling. His television background taught him the importance of that. From Tom Cotter’s biography, “TV Tommy Ivo: Drag Racing’s Master Showman”, one learns that Ivo wasn’t interested in championships or trophies (in fact he often sold the trophies he had won back to the promoters), but he was interested in purses. Ivo treated drag racing as a business and maintained a brutal touring schedule. The Nailhead had good low end torque and was reliable. Ivo claims that he didn’t have to hammer his Nailhead for that reason. Rarely did Ivo have to miss an engagement due to engine failure.
What I heard/read was that Buick/GM wanted the V8 for the old body, the one for the straight-8. They wanted the V8 to fit into the long & thin hole for the straight-8, so the engine was designed to be as thin as possible.
I never heard this, but I suspect the vertical valve design of the nailhead V8 was a marketing trick to keep straight 8 enthusiasts. With the 2-offset inline fours (that make the V8) it appeared like a straight eight (with a little imagination).
Ford did that with the first Ford V8. It looked a lot like 2-inline fours. I own 2-old Buicks: a ’56 and a ’63. The engines do appear similar to a 320 inch straight eight. They are, of course, different. But I can see it.
Tommy Ivo was one of the first American drag racers to race in the UK,he was quite a character.
Ivo’s Single Nailhead dragster won over 70% of the races he entered it in, it held the Drag News Standard 1320 record for B/GD for over two years. His twin Buick was way ahead of everyone else in the field. That car was the first to break into the 8 second barrier, also he set MPH records of 170, 173, 175 and 180mph. This was in 1959/1960. After Tom sold the Twin Buick to Speed Craft of Chicago, it went on to run it’s best @ 8.21@ 193mph in 1962. The Twin has been restored and resides in its permanent home @ Don Garlits Drag Racing Museum in Ocala FL
I have a Buick post war history book. GM management decided that engine bays were going to be shorter and straight eight (or V16s) were not going to fit in the near future. Buick toyed with a number of narrow angle V8s but were concerned with fitting a 90 degree V8 into the engine bay designed for a straight eight. Hence the valve design. The real question is why they did not redesign the valves when the engine size increased to 364 cubic inches or 401 in 1959. The bodies were redesigned before 1959, so the engine bays should have been redone. I suppose that new tooling would have been needed and they were avoiding that. The dynaflow development was probably taking all of the development cash.
i have read alot of comments but what i am looking for is info on supercharged nailheads from factory gm and government would not let out for public purchace due to tq specs. any info?
This was privately funded in 1960 with dynaflo trans. 2800 lbs and 112 1/4 mile time
and if any 350 chevy guys read this check the specs,stock 401buick,325hp,445ft.lb. tq. chevy,270hp.280-325 ft.lb. tq.and the buick is only 30 lbs.heavier than the chev,not to mention the peak tq.is at 2800rpms,i built a 1974 pinto wagon u sat in the back seat to drive the motor was in the front seat,nothing under the hood but radiator and battery,the425 had 257000 miles on it when we pulled it from my uncles 57 chevy belaire,9inch ford rear,370 gears,switch pitch automatic with 400 guts,2800-3200 stall converter,dual 650 carter afb carbs,it was bored 030 over and balanced before it went into the 57,evey time we ran on the streets it jumped EVERYBODY 6-8 cars out of the hole,the driveshaft was less than a foot long,the whole car costed $1600 to build and guys with 50k just in their engines were scared to run it. at3200 lbs. and on roadhugger radials at the strip it ran 12.7@107. we sold the car years ago but recently seen it at a local car show,the new owner is a lying douch who tried to give a false account of what HEdid to it, but the ford blue stripe i put from oil pan to trans pan said it all, i am willing to bet that nailhead has over 325000 on it and would not be surprised.REMEMBER,NAILHEADS ARE MEANT TO BE HAMMERD
My first car was a 57 Buick Special. An older couple had it and the back seat still had the factory plastic cover on it! This was 1968 and I was 18 at the time. Really liked the car, but the dynaflow kinda sucked. The 364 had torque though. One time I power-braked it and tore the engine mount in half. The engine rotated under the hood and destroyed the distributor which was mounted at the rear of the engine. So after that I was a little more careful…
I remember the racers using a short chain from the exhaust header to the frame to keep the nailheads from ripping out the mounts
Torque City USA! My right hand engine mount on my ’60 Invicta Flat-Top was ripped as well. The air cleaner would smack the inside of the hood. Great engine. Had another 401 Nailhead in a ’65 Riviera. What a car.
Very glad this article was brought back as I am new here.
Excellent write-up. I learned a lot. Thank you!!!
have a 1965 buick lesabre 400 it is suppsed to have a 401 nailhead is this so. i have the engine # looks like #1366895F 2GM is this right
Pete, is the car called 400, or some other part of it called 400? A decal on the air cleaner saying 400 would indicate the torque availability of the engine. A 401 nailhead w/a 4-barrel carb would say 445 on the air cleaner indicating torque. My ’65 Buick brochure shows just 2-available engines for the LaSabre: Wildcat 310 & Wildcat 445. The 310 is a 300 CID unit with 210 Horsepower. The Wildcat 445 (optional) is a 401 CID unit with 325 Horsepower.
Probably because both of Oldsmobiles engines were bigger than the Buick engines (a 330 and a 425). When you charge more money, you at least have to make your customer think he is getting more engine.
The executives @ GM stated that no GM engine would have anything over 400″ the 400 is a relabeled 401.
The Buick 350 IS NOT a Nailhead.
The 400 CID limit was for midsize cars, not full size. But Buick used the 401 in their muscle car until 1967 when new engines were introduced with 400 and 430 CID.
Googling LeSabre 400 package brings up a couple of sites that suggest this is the 300 cid engine with 4 barrel carb and superturbine 400 automatic. LeSabre’s generally came with smaller engines than the Electra although early 60’s LeSabre’s had the 401 with a 2 barrel I suspect.
The nailhead engines were not great designs, but Buick’s performance was controlled by the dynaflow transmissions more than the engine performance.
The “LeSabre 400” was a trim package available for several years. The “400” has nothing to do with the engine, as these came only with the 300 or 350 V8, not the 401 Nailhead, or the 400/455 engines.
The standard engine for the LeSabre was the 364 for 59 thru 61, then the 401 rated at 280 hp was standard for 62 and 63. Then 64,65 was a 300 CID engine based on the cast iron V6, which was based on the aluminum V8. This engine was increased to 340 CID for 66,67. After that a 350 CID version was standard until the late 70’s.
I don’t think the “LeSabre 400” was available before 1965 or so.
I think that is true. If Jolopnik’s website is right, then the “400” had something to do with the TurboHydramatic 400 (call Super Turbine 400 by Buick) transmission, which was included with the package. This transmission replaced the older turbine drive in 1964. My postwar Buick history book does not get into options for the various models.
What I do know is that the “big” engine (the 325hp 401) was standard on the Invictia. I don’t think this engine was available on the LeSabre.
The 325 four barrel 401 was an option in 63 in the LeSabre. I don’t know about other years. The 401 with 10.25 compression ratio two barrel was standard in 62 and 63.
Pete at the top of this series of posts wondered if the “400” on his 65 LeSabre implied that the engine was a 401. Probably not is the answer. But for those who wonder if they have a Buick nailhead engine, look at the valve covers. If they are vertical, then yes, you have the nailhead. If you are not quite sure what the valve covers might look like, google Buick nailhead for pictures. Also google a Buick 350 (or some other engine) for pictures of “normal” valve covers. There are good pictures at the top of this webpage too, with some diagrams of normal valve covers.
The LeSabre did have the 401 nailhead in the 62-63 period. I don’t know what options might have been available, but probably the 325 hp would have been an option. For some reason the LeSabre got the 300 CID engine in 64. I don’t know if the 401 was an option then. I do know that in 67 only the small block V8 was available (I have a price guide with options). But in the 70’s the 455 was optional.
The real difference with the Nailhead from the “Small Block” 215-300-340-350 is the location of the distributor. The nailhead is on the back of the block and the other V-8s as well as the V-6s have the distributor on the front of the engine angled to the side .
The nailhead engine has valves that are too small for the engine to develop the power that it could if the valves were more conventional. The V6 and the 300 CID (and then 340 and 350) V8 are all based on the same design. The valve covers are what give away the nailhead engine.
The 215 and 300 as well as the V6 were not nailheads but had fake nailhead valve covers until thru 65. The sure thing is the distributor.
In reply to Fred’s comment about the valve covers…
The early V6 and small block Buick engines got valve covers that looked a bit like those of the Nailheads. The heads were conventional design (but differed from those on the later big blocks and 350 engines as they had evenly spaced intake and exhaust ports instead of being opposed). The valve covers on the 300 and 340 engines are taller on the exterior section to make them look a bit like those on the Nailhead engines. One easy way to tell if an engine is a Nailhead is to look at the distributor. It’s the only Buick V engine to have it mounted at the rear.
Here’s the 401 in my 1965 Wildcat (I know it needs detailing!).
LeSabre ‘400’ was primarily a ’65-66 option. The standard ’65 engine was a 300 CID, same as the Special/Skylark engine, with a 2-barrel. The only engine option in ’65 was the ‘400’ package, which gave that 300 CID a 4-barrel carb.
In ’66 the LeSabre ‘400’ put the 4 barrel on the ‘new’ 340 CID engine, which was also used in ’67. In ’68, this became Buick’s 350.
Buick created a lot of confusion by listing torque #’s instead of CID on the air cleaner…it showed Buick’s emphasis on torque….it also made people think they were getting a bigger engine!
S tandard 300 meant the 2 speed variable pitch Super Turbine 300 trans, 400 was the 3 speed variable pitch Super Turbine 400 trans. The standard 300 cu in was 2 bbl, 210 hp, 9:1, 310 ft.lbs@2400 rpm, optional 300 was 4 bbl, 250 hp@4800 rpm, 11:1, 335 ft.lbs.@3000, these were the ONLY LeSabre engines in ’65, up to 340 cu in in ’66. Any with 400 exterior tag meant 3 sp trans. through 68-69.
The SR-71 starter were nailhead 425’s, Lincoln 460’s were tried, but went back to the Buick 425’s for dependability. Yuba College is next to Beale AFB, you could hear the starter pac next door, later knew the Commander of Beale (he also flew the SR-71). Have had many Buick’s, nailhead and other. the 53-66 engines (425 most) dependable engines of any cars I’ve had (pic of my ’63 Electra w/458,000 mi) . The 430’s (’67-’69) were fast, had several, but they had a bad habit, if overheated, of becoming a 4500 lb paperweight until engine replacement, the 455 eliminated the prob.
The “400” package on the LeSabre consisted of a 3 speed “400” transmission and a 4 barrel carburator. The 1965 LeSabre had the 4 barrel version of the 300 ci engine (Wildcat 355).
In 1966-67 the LeSabre 400 got a 4 barrel 340 instead (named Wildcat 375, and which wasn’t related to the low compression 401 of 1962-63 that had the same name and torque rating) and a Buick 350 for 1968-69. The option was dropped in 1970 as the LeSabre got a THM 350 transmission as a base automatic. There was a new “LeSabre Custom 455” model that year which had the 400 transmission but also a 455 engine but that car replaced the base Wildcat model of 1969, not the LeSabre 400.
Here’s the list of available engines for 1965 (it’s a Canadian document so the info about transmissions differs from the US models). The LeSabre 400 has the engine on the upper right corner. The Nailheads are in the lower row.
Here’s the list of engines that were available on 1965 Buicks. The LeSabre 400 has the engine on top right corner, the Nailheads are in the lower row.
This is from a Canadian brochure so the details in the text differ from what would be written in a US brochure.
Your ’65 leSabre ‘400’ is a trim level, not an engine designation. The ONLY engine you could get in a ’65 leSabre was the 300 CID. In ‘400’ trim, it came with a 4-barrel, and with the 3-speed TurboHydramatic 400 (Super Turbine 400) tranny…a very good tranny, by the way, with it’s switch-pitch torque converter!
That’s a Pontiac the guys are swapping the engine out of above, it’s not a Chevy.
+1 – Looks to be a 1954 model…
A bit older from the presence of a two piece windshield, which disappeared in 1953. Might be an Olds from the look of the wheel covers.
Might be an Olds 76 or 88 that used the smaller lighter Chevy body with an added ‘Buick’ grill and/or front fenders/front end to give a lightweight ‘Buick’ ‘funny car’…
mild custom 1951-52 chevy with ’54 pontiac grille olds caps
Cross section of GM LeSabre roots blown aluminum engine are on my Facebook page “Looking Back Racing” along with another hundred such views of the rest of the V8 universe. I tried making them all scaled but found that downloading resizes to 960 x 600 pixels and I have to recheck which are affected by that. Usually its the ones with a different aspect ratio. Nonetheless, visit the site if you need the reference. Most of what is up has had lots of clean up, so it is not burdened by anyone’s property rights.
Actually the 307 Olds wasn’t the last American carbureted V-8 engine to pass emissions (“in 1990”). The AMC 360 was the last one — in the 1991 Jeep Grand Wagoneer.
If the tortuous exhaust porting and small valves were the main problem, couldn’t they have just designed new heads for the nailhead block? It seemed to have a lot else going for it.
One would think so, however, it may have required new tooling for making the heads. This would have made sense by the end of the 50’s, but probably by then any major changes to the engine design would really only make sense if the whole engine is redesigned. Cadillac redesigned their V8 for 63 (so that the 64 could become a 429 CID) and this new engine is lighter weight than the original 331. So I think by the time redesigning the Buick heads makes sense, the whole engine is probably in need of redesign.
What I find curious is that the 401 Buick engine is rated at 325 hp, the same as the Cadillac 390, although at different engine speeds; 4400 RPM’s for Buick, 4800 for Cadillac. Pontiac 389’s are rated at 303 hp, but the torque is 290 at 2000 RPM’s, so this may make sense.
The Nailhead block apparently couldn’t be made any larger than it was at 425 cubic inches and I guess the new 430/455 were a bit cheaper to manufacture… I have Buicks with both the Nailhead and later V8 engines and I have to say I much prefer the Nailhead. They had better oiling systems and forged crankshafts which the 430-455 lacked… The heads are also more prone to crack or to head gasket failures on the newer engines.
As with a lot of GM’s mid-60s engine redesigns, one of the motivations in redesigning the block was to accommodate newer casting techniques and trim some weight. Not all immediately went to thinwall casting (due to limitations in foundry capacity, if nothing else), but I gather provision had to be made in the block design.
I think the next-generation 400/430/455 shared the same bore spacing as the Nailhead (to allow the use of existing transfer equipment, I assume). They had a different bore/stroke relationship, but that was essentially because the new layout was better for emissions control, which hadn’t been a concern previously.
The webpage that I found the Pontiac specs on is probably wrong. The torque should have been more like 390, and I think that was the base 389 with closer to 200 hp. The 303 seems to have 425 lb-ft of torque @2800. At least the website I found this on seems right. I do have to wonder about both Pontiac’s and Cadillac’s horsepower ratings.
I wanted to know the difference between the 322 and the 364 Comparing and contrasting and interchanging parts. Sadly you didn’t tell me anything.
My Buick history book indicates that both bore and stroke are increased. Camshaft is different, as well as valves and intake manifold. I don’t know what you might have in mind, but I don’t think a lot of parts are interchangeable. The 322 went through a number of changes too, to get the horsepower from 188 to start with, and ending at 255. But the 364 started off at 300 hp and did not change.
However, you might be able to put a 364 into an early buick with a 322. But there could be major problems with connecting to the dynaflows, which under went changes on a regular basis.
You’re kidding, right?
Have a question for you all. I have a 1957 buick special original miles 60,000
no parade car bur nice ride. My problem i am on my fourth manifold on drivers side. Have heads re grounded went with no gasket and she now is cracked again.
Any thoughts any body
Great article. I remember the Nailhead combustion chamber being described as like that of a Duesenberg, except with 2 valves on one side. That lends a little support to the theory that Buick may have intended to develop a 4 valve version eventually. No question the valve arrangement made the engine easily fit into cars designed for a straight 8 though.
Awesome! The nailhead is its own legacy, and its sad to see how far Buick has fallen. Up thru the days of the Grand National, Buick was a brand that actually meant something. Now..it means something alright: frumpy old sedans wallowing in the left lane 15 mph under limit, blinker on for miles….
Whats REALLY impressive here is seeing pics of those old dragsters and hotrods. Im always in awe of the sheer skills and innovation shown by old school rodders and racers. Back then there was no internet…you couldn’t just youtube ‘how to hotrod’ and watch a few videos then go wrench on your car, avoiding the pitfalls of trial and error. These guys literally blazed new trails all by the seat of their pants. Great writeup!
15 MPH under the limit! Not with a Nailhead!
Just have to be careful with the brakes at this speed (even if this car has aluminium drums which were considered the best drums back then they are not too good at getting the car quickly back from 120 to the speed limit!).
The aluminum drums on my Electra stop my car just fine from triple digit speeds……..once lol after that they fade like crazy
My brother put one of these into a Kaiser Manhatten back in the 60’s. It would cruise at 150 mph until the generator would fail. It took an hour to rebuild and back on the road again. I got to solo drive it when I was 2. Downthe driveway and out into the yard. Mom was screaming at me as she chased me down the driveway.
I knew a Navy Chief that drove his family from California to Panama back in the seventies. It’s obvious to me now that I don’t know the size of the engine but it was a nailhead. He had stuffed it into a 3/4 or one ton GMC truck with a slide in camper. He said that the engine swap improved driveability and mileage. I always thought it was neat that some people were innovative like that and then actually drove what they made.
I loved those old nail head engines. They sure had the torque. I put one out of a 66 Riviera in a 65 Skylark that started life as a V6 back in 1971 and went drag racing with it.
When my sister was learning to drive one day in my 4-speed 1966 Buick GS 400 (with the “Wildcat 445”), she let out the clutch and at 45 or 50 mph asked me when to shift to 2nd gear. My answer was, “Just shift into 4th – you obviously started in 3rd rather than 1st” (which was barely noticeable due to the tremendous torque the engine produced).
Not sure if Buicks were still nail heads in 1970 but back in the 80’s a car magazine did a drag test on a 70 Plymouth Hemi & 70 Buick GS.
The Buick won , 3 out of 3 races I think it was.
I hated writing this ,I love Chryslers and I’m sure the Plymouth would have caught the Buick if they kept at it longer than the 1/4 mile.
But those Buicks must have been awesome engines
The hemi engine certainly makes more power stock than a stage 1 motor did . A lot of people don’t realize how conservative the carburetor jetting and ignition timing were on cars back then. Just playing with these settings can net you the difference between those two cars. I love Buicks so don’t get me wrong its just I do not like seeing false info getting put out there.
and no the 1970 GSX motors were 455’s not related to the nailhead.
I have noticed that cars powered by big block Buicks tend to be significantly fast than their dyno sheets suggest. I have seen 400hp Skylarks run times faster than 450-500hp BBC Chevelles.
On the Buick site I belong to they always say not to pay attention to the dyno numbers. Maybe its the way they make torque who knows?
Horsepower makes faster benches. Torque makes faster races. The stock 455″ Buick had 510 foot-pounds of torque at only 2800 RPMs.The Olds 455 made the same amount of torque, but at 3800 RPMs. Horsepower number was very conservative on the Buick at 360 at 4200 RPM, 390 for the Stage 1 motor, and it easily would tach up into the mid 5 grand mark putting it above 400 horses. The Chrysler Hemi was rated at 425 horses at 5000 RPM and 490 ft.lbs at 4000 RPM
Hemi Chryslers were also very heavy engines, above 700 pounds. The big block Buick produced its stump pulling torque out of a high nickel content cast iron block that weighs only 25 pounds more than your run of the mill small block Chevy.
With those numbers in mind, it’s pretty easy to understand why and how the Buick GSX would consistently beat the Plymouth GTX.
Another nailhead lover. I had two different 66 Rivieras over the years. A 425 with the turbohydro switch pitch. Great running cars that could pass anything but a gas station. Not really but I could only average about 12 mpg. on the highway. Sounded great through a set of glasspacks. Love Rivs but no more gas hogs for me. Premium was 3.25 a gallon when I sold my last one. The nailhead was a really beautiful motor. O’brien truckers has a fantastic finned valley cover to go with the finned valve and spark plug covers.
Thank you for an informative article that inspired equally informative comments (for the most part).
A few Buick notes:
-Always felt is was misleading how Buick labelled their engines. In the 60s, an Olds 330 clearly outranked a Buick 300, even if the latter was called a “310”. Was mollified upon reading that torque had been a Buick focus for years. (They needed it with those transmissions!)
-Thought that 50s portholes were based on model, with the Roadmaster having four and others three. Then read that the number was based on carburetor, with 4 barrels getting 4 ports. Hmmm.
-Always thought the Buick 300 was a nailhead based on its vertical valve covers. Amazing to learn that its’ not.
-Saw a great custom last summer. Old Buick with a modern big block. The remarkable thing was custom fabrication that looked exactly like a nailhead. Wish I had pics (next time)!
-I remember calling the early 50s Buicks “old stones”, surely a term picked up from a car magazine. They certainly seemed like stones, whirring along with straight eight and Dynaflow. Always got a laugh from my high school friend Ralph. I would certainly like to hear one now.
The number of portholes were based on the number of barrels in the carburetor. Century’s, Supers and Roadmasters all had 4 portholes.
Well not exactly! The 1954 Century had 3 portholes and a standard 4 barrel carb. The 1949-51 Roadmaster had a two-barrel carb but 4 portholes.
And in the 1960’s only the Electra had 4… The Invicta and 1962-63 Wildcat had standard 4 barrel carbs and also had only 3 portholes. So did the 1965 Skylark Gran Sport and the 1965-69 LeSabre 400. My 1974 LeSabre also had a 4 barrel carb and just 3 portholes…
4 portholes matching 4 barrel carbs and 3 portholes for 2 barrel carbs would have been true for just 3 years, 1955-56-57…
Right you are Phil, but confusing indeed. My answer was based on my familiarity with the 1956 Buick Super, as a friends father had one and it had the 4 portholes. The Roadmaster always had four and I recall the CHP 1955 Century as also having four.
The Super was an interesting model. On the larger Roadmaster frame with the Roadmaster dash and the more powerful V-8. His was a black 4 door sedan with Dynaflow, PS PB PW and the very cool Wonder Bar radio. It was handed down to my friend in 1969 (with less than 60,000 miles) and we spent a lot of time in it. Lazy pick up off the line, but plenty of cruising power. Very scary handling with the bias ply tires of the era and smallish drum brakes. The 1973 gas crisis marked the end for it, as I recall it got about 10 mpg of premium fuel and was pretty much done anyway..
To start with the Roadmaster got 4, the rest of the line 3. In 1955 the Special still had 3 but the rest 4. The whole thing started when one of Buicks sylists (Nickles) put some on a 47 Super convertible (with lights in the portholes) and then on 48 Roadmaster. After this was seen by Curtice they were added to the 49 models without the lights.
The Cord’s Lycoming V8 was mentioned above in the comments. I’ve always been fascinated by these.
Here’s a cross-section of their V12, which was similar. Horizontal pushrods from a high-mounted cam in the block, and a “bent” block face covered by a flat head forming the combustion chamber. A machinist’s nightmare?
Take a look at the Oakland flathead V-8 of 1931 or so. Kind of similar.
Interesting article Paul. A side note on the J-58 engine in the SR-71, I worked at P&W’s Florida facility (west of West Palm Beach on everglades land) where these engines were originally designed (and were overhauled). They ran them on an outdoor test stand which had a ‘slave’ jet engine plumbed to the J-58 intake to simulate (some aspects of) high mach number flight. When in full afterburn they made incredible noise that could often be heard in Jupiter, FL which was roughly 13 miles away. Somewhere I have a photo of the whole afterburner section glowing red… Quite a beast.
Admittedly, this is all way over my head. Just give me a cool-looking car and I don’t care what’s under the hood, hence my continual reference to “a 250 cu. in. 6 cyl. Powerglide”.
My old buddy’s dad had a 1963 Buick Electra 4 door hardtop with the Dynaflow tranny. A very smooth-running car.
However, I do appreciate the power my current ride has, and I wouldn’t swap that drivetrain for what I said above!
Very informative article, nonetheless.
By 1964, they had ST-400 transmissions. Non-Switch Pitch for the first year (then the 1965-67 got the switch pitch converter back. The ST-300 had the Switch Pitch in 1964-67.
variable pitch 1964 through 1967 in Buick, same in Cadillac
Speak of the devil. On Sunday I rounded a corner to make a left turn as another car came from opposite me to make a right directly behind me. Attracted my attention as soon as I got a glimpse. We then made a right turn and darn he pulled in behind me. Ok, one more left turn and maybe the light will stop us and he will pull next to me.
Luck is with me and I ask if it is 64 or 65 and it is a 64 Electra 225 with a 401 nailhead engine. Yes, the idle is lumpy compared to my Mercury 410 as we talk light permitting. Too soon over as the light is green and we need to me. Driver maybe in his mid to late 30’s. The last time I saw a 64 Electra 225 has to be way back in the mid-70’s. Triple black with a low gloss shine typical of older paint.
In 1956 Chevrolet started to manufacture a few heavy trucks alongside the medium duty models they had offered for years. Problem was that while the 235 and 261 6’s and new 265 V-8’s had been quite adequate for trucks up to 2 ton, Chevy clearly needed a larger engine for their new tandem axle jobs. Enter the Buick 322. Buick supplied Chevy with special heavy duty low compression versions of the 322 which Chevy named Loadmaster and Super Loadmaster depending on carburetion (2 or 4 bbl.). These engines were offered until they were replaced by Chevy’s own 348 in the late 50’s. Some of the 322 powered Chevy’s used early Allison Torque-Matic automatic transmissions.
The Buick brand actually stood for something uniquely American–BIG TORQUE.
Now Buick stands for “cheap chromy ovoid grille (to excite Chinese Buyers) pasted on front of generic GM platform”.
im looking at a 1953 buick riviera 4dr is the motor in it dependable and waht should i look for please email me soon
In late 1959 my older brother Pat (passed) bought a 53 Super Model 56R 2Dr out of the junk yard for $85.00. After a year the transmission failed, it sat in a field for 4 years in Up State NY. Pat then gave the car to another brother Richie that just got his license. Well Richie removed the transmission brought it to the Bronx to have it over hauled. Went back Up State, put the rebuilt transmission back in the Buick. Drove it 150 miles back to the Bronx and the transmission was burnt up again! Did the whole operation again. The transmission lasted a week and it burnt up again! Richie did this 3 times, thinking he did something wrong while replacing the transmission. He brought the Buick to a well know transmission builder. The service writer told Richie to sign a statement that the motor mounts were broken, and if he didn’t replace them within 5 working days the warranty will be void. So Richie replaced the motor mounts! After that! he couldn’t keep rear tires on that Buick! It would smoke the tires really bad, that little 322 was a freak! That wasn’t fast enough, Richie put a Roadmaster intake manifold and a 4 barrel carburetor and took the 2 barrel off. It would really badly smoke the tires in Drive, not Low. Many folks would say that the Dynaflow transmissions were sluggish. With the Straight Eight engines they were sluggish, with the V8 engines it was a different story. I witnessed it all, I was 12 years old! I grew up missing that 53 Super 2Dr Riviera. I never did buy one and restore it. Instead I restored a 48 Roadmaster 2Dr Sedanette which I had for 39 years in memory of my Dad. My Dad had a 42 Roadmaster Model 71 Sedan. You can view photos of both the 42, and the 48 by typing in My Dads 42 Roadmaster The green Hornet
I had a 55 Century wagon that no one in town wanted to race. It had a fairly high gear ratio for a Buick and it screamed. I later had a 59 invicta that blew the doors off a J-2 olds tripower. It would top out at about 125 on the highway, but the rear end started to float at that speed with the big fins. It had resonators and no mufflers…what a sound, and it had the balls to back it up. RE the chevy/pontiac debate, it’s definitely a chevy with the grill bar from a 54 pontiac grafted in. That was a pretty popular swap into all sorts of cars back in my day.
A lot of Buick engines are found in boats. Even back in the straight 8 days.
Loco Mikado wrote in part – “A lot of Buick engines are found in boats.”
Yeah….both nautical ones and the road-going kind! 🙂
Final nautical act, anchor!
I can’t help but think what might have been if Buick had further developed the
engine used in XP300 concept car and put an enlarged, (maybe, sticking with a theme, around 322 cubic inches!), slightly tamed down version of it into production. While the Roots supercharger and dual-fuel gasoline/methanol fuel system may have been a bit too exotic and ‘over the top’ for a production car of the time, the rest of the engine’s basic design – notably the pent-roof cylinder heads and the unique and ingenious cam, lifter, pushrod and rocker-arm layout necessitated by the cylinder head design all would have been eminently producible and would have, I’m sure, been an absolute world beater.
Fascinating article but I don’t understand the appeal of nail heads to hot rodders. Weren’t readily available Cadillac/Oldsmobile conventional v8s more easily soured up?
Rbaime wrote – “Fascinating article but I don’t understand the appeal of nail heads to hot rodders. Weren’t readily available Cadillac/Oldsmobile conventional v8s more easily soured up?”
While all of the then new early-’50’s first-generation GM OHV V8’s that you mention – including the Buick – had huge horsepower and torque advantages over the venerable Ford flathead V8 of the day, compared to the,about equally powerful in stock or near stock form Olds and Cadillac OHV V8’s, the Buick was both a bit lighter and most importantly, narrower and thus could be more easily fit into early Ford (- ie – Model T’s and Model A’s particular) and other make chassis, many or most of which had been designed for inline engines.
Thanks. Makes sense. Another topic for all: why does Corvette stick with the pushrod small block? GM has the Northstar and all kinds of dohc technology and tooling for its dohc sixes; ford has a jewel v8. Stirling Moss called the small block a “cooking stove” engine. Mind you, I like it-my CTSV has one, but still….
Ps I realize there are size issues but they did have the very expensive ZR 1 for awhile.
In 1976 , a guy that I worked with , decided to put his 1963 Buick LeSabre Two Door Hardtop up for sale . Check this out : It was equipped with a factory four-speed on the floor , no power steering . It was oxidized White outside , no dents at all , pitted chrome , but totally original . Inside , a Blue cheaper interior , slightly worn , with dash and rear deck baked by the sun , but also completely original . He was the second owner . I literally “had to” buy it . It was genuinely a “rocket ship” . By the way , I have never owned a car that was easier to replace the whole exhaust system , laying on my back , than any other car that I’ve ever done exhaust work on .
If I have opportunity to buy a 63 Buick Lesabre in great condition for show. Running driving and stopping just fine. Clean inside and out for about $3100 should I go for it? It has 119xxx on it I doubt its just 19xxx. It has a little bit of pitting in the chrome on the tail lights. I haven’t seen it in person yet.
Had a 55, 61, and 64 Buick’s. The 55 was the best riding car I ever owned. Though it could not get out of its own way it cruised easily at 80 and felt like in your living room. The 61 lasted well into 200k miles and had plenty of power. The 64 lasabre had switch on the transmission that I put a toggle sw to control the down shift at will. I was routinely out running 383 road runner from the get-go. My father almost always started out in low and shifted to drive and I never knew why. The nailhead motor had plenty of get up and go if you knew how to make it go. Those engines lasted longer then any other we owned.
“Naihead” because the valves were so long they looked like nails.
Talk about a low-performance engine.
Put the heads on a flowbench and have a laugh.
I enjoyed reading all the comments, now i know more about my tire shredding nailhead
Another fan of racing the Buick Nailheads was Max Balchowsky, who used the V8s when campaigning his Old Yeller II road racing sports car. He used them well after Chevrolet V8s became popular, as he said he could build a racing Buick for a fraction of the price of a Chevrolet. Old Yeller II enjoyed considerable success against the best European sports racers, while enjoying the driving services of stars like Dan Gurney and Carroll Shelby.
I’m not sure if this was brought up anywhere in the comments or not, but I’ve read that one reason for the Nailhead design was that the ’53 Buick’s engine compartment is quite narrow, as it was truly designed for the straight-eight. Half of the width in the engine compartment of my ’53 Special is taken up by the fresh air inlet vent tubes that travel from the radiator support back to the firewall.
Joe Turlay was apparently largely responsible for the design of the LeSabre/XP300 engine and the Nailhead (and the Buick V6, actually), so maybe he used a half of the XP 300’s valve setup to keep the engine narrow enough to fit in their existing bodies.
It’s the most commonly-repeated one.
But one has to wonder if they would design an new engine, one they had to know would be around for quite some time, just to fit the very last year of that body generation. That seems a bit odd to me.
And I have to wonder too if that engine compartment couldn’t have been easily widened. It’s the same basic body as Olds and Cadillac used with their new ohv V8s. How is it different?
I Googled for some engine compartment shots of a ’53; it looks like there’s a fair amount of room on either side of the nailhead. I can’t see it in great detail, but it doesn’t look all that tight.
I’ve come to dismiss this argument, because there are too many logical arguments against it. It seems like an easy, quick answer, but I seriously doubt it.
Had a life long friend, a Buick factory master mechanic, ask why the narrow design, he raised the hood on my ’63 Electra, said, ‘How long to tune it up?’ It takes about 20 minutes for plugs, points, condenser, replace fuel filter, check timing, that’s with ps, pb, electro-cruise, a/c plus added air horns. He said Buick was aware more and more accessories would be added and considering a design that literally would save thousands of man hours for shop tune ups, after assuring it viable in all ways was what happened. Don’t know if true, but they are the quickest tune cars I’ve seen. My Hemi DeSoto and 440 Imperials take an hour for plugs alone, (and the Imp’s are under the car to reach them). also engine mounts take app 20 min each on the 425. Even my ’64 and ’65 Riviera’s are easy.
I just googled for some shots of a ’53 Cadillac engine compartment, and it looks the same in its configuration and size and shape. Why would two GM cars with the same basic body have a different engine compartment width? Makes no sense to me.
Buick would have obviously known about the 1954 models as they were designing the Nailhead, so the width being the main determinant does seem thin. My comment came from the Norbye and Dunne book “Buick 1946-1978 – The Classic Postwar Years,” which includes quotes from Joe Turlay. I assumed that since they spoke to him, there must have been some merit behind their assertion that Buick wanted a narrower engine, even if that wasn’t one of Turlay’s first-person comments.
I went back and reread the section about the Nailhead, and I gathered that Joe Turlay was sold on the pent-roof combustion chamber, and he was certainly proud of the engine’s head flow (!). He seemed to take offense to its “Nailhead” nickname, and claimed that they tried larger valves but they didn’t work very well, and that the Nailhead’s strength was a combination of valve/port size and cam timing, but he may have been a little biased. 🙂 He also (probably rightly) claimed that the Nailhead was one of the quietest and most durable of the American V8s.
In reality, I think Joe Turlay designed the engine he thought was best, probably within the cost parameters you mentioned, and the narrow width just happened to be a side benefit. Plus, the engine just looks cool.
claimed that they tried larger valves but they didn’t work very well,
That’s a bit disingenuous,as there was no room for bigger valves. That’s the downside of this configuration, as it’s essentially one half of a four valve pent roof.
The thing to remember is that Buick really tried to throw its weight around, and go against the common GM thinking at the time. Which explains the Dynaflow “No, we can build a better automatic than the Hydramatic”
The obvious thing would have been to design a edge-head V8 as Cadillac and Olds had already to be shown to be the best way. But Buick’s NIH (Not Invented Here) syndrome kicked in again.
Buick was a fiefdom somewhat of its own then, as they had been what kept GM afloat during the early years, and were its most profitable division for a very long time.
Ever notice how almost all of Harley Earl’s favorite and most influential concept cars were Buicks?
Apparently, Harlow Curtice approached Harley Earl during his early days at Buick and asked him what he drove…when Earl replied that he drove a Cadillac, Curtice asked him to design a Buick that he’d like to drive. From that point on, it seems like they had a pretty good relationship. As Curtice went on to lead GM, he continued to drive Buicks. One of his cars, a ’57 Super of all things, is at Sloan Museum in Flint.
Curtice’s partiality to Buick (and Earl’s) certainly couldn’t have hurt the division’s fortunes.
Paul your comment that Buick was a fiefdom is correct, and Harlow Curtice helped make that reality. Your comment about the Dynaflow is not correct however. Buick could not use the HydraMatic because it’s clunky shifting did not work well with the torque tube drive. Too much clanking got transmitted to the drivers seat. Chevy had torque tubes as well and the Powerglide was sort of a junior Dynaflow for the same reason. Now Buick’s pull withing GM allowed them to develop their own transmission, so that’s supports the fiefdom argument, but they didn’t do the Dynaflow just to be different.
Nailhead’s have always fascinated me, they just looked so different.
Buick could not use the HydraMatic because it’s clunky shifting did not work well with the torque tube drive.
I’ve heard that argument but don’t buy it. Nash used the Hydramatic for years, and also had a torque tube/coil spring rear suspension just like the Buick. And there may be others.
It sounds like rationalizing.
Here’s the real reason, and it’s a good one: The Hydramatic didn’t use a torque converter. It only made sense that GM also explore the use of the torque converter in an automatic. Which of course ultimately became universally used on them. The Dynaflow was a completely different approach to the question of automatics, and they were right to pursue it.
My point was that it’s not surprising that Buick would be the one to do so. They were big, independent-minded, and had the resources. But they didn’t “invent” the Dynaflow, it came out of the same GM tech group that had developed the Hydramatic. Buick liked the smoothness of it, and adopted the design to develop it for production.
The Hydramatic was jerky in every car. 🙂
The reason I never liked Buicks, they used expensive complicated solutions to simple problems… and they didn’t work as well…
To get the Nailhead up to competitive HP ratings, they used a big durations cam… to achieve the HP within the low RPMs limits of airflow from the small valves, they used a lot of cam lobe overlap… both those things together resulted in 10-12 MPG vs competitors’ 15 – 17 MPG…
Buick used the inefficient DynaFlow tranny… further hurt MPG…
Buick used a troublesome constant velocity joint in it’s driveshafts…
My father always said you floor a Buick and you blow the seals out of a Dynaflow… sure enough, we floored my friend’s Dad’s ’51 Buick once and tranny fluid started pouring out on the street… we slipped it back into his Dad’s garage… but it left a telltale trail all the way there…
I have a Buick aluminum 215″ fake nailhead in my ’75 MG Midget with BW T50 5 speed tranny. I would have preferred the Olds version but the 45 degree valve covers almost touch the ‘frame’ boxing of the unibody and hide the spark plugs… The upright valve covers of the Buick give full view of and access to the spark plugs… And the V8 is vastly smoother than the rough little 3 main bearing Triumph Spitfire iron 4 banger the factory put in that with tranny both self destruct in only 25K miles at USA Hiway speeds. The aluminum V8 and aluminum 5 speed are also lighter, better MPG, 3 times the torque and HP… no negative effect on handling… plenty of power for a 1800 lb. car…
I have the book you referenced. My understanding is that Buick had a narrow angle (22.5 degrees) V8 that somehow failed to work out. My guess is that there may have been some “I told you so” comments made to Buick when the 22.5 degree engine failed. So I speculate that to save face Buick came up with nailhead design. They may have thought it was a good idea at the time.
During World War Two Buick’s contribution was a tank with a torque converter transmission. The turbine was divided into three stages with two upper stators. This produced a 4.8:1 torque ratio. After WW2 Buick thought they could develop a shiftless torque converter transmission with smoothness of operation the primary goal. Before WW2 one measure of a luxury car’s quality was how smoothly it could accelerate from idle in 2nd gear.
” … the ’53 Buick’s engine compartment is quite narrow, as it was truly designed for the straight-eight” has been mentioned a dozen or more times before your quote.
Over the years I have read or watched several explanitions of the Nailhead engine and why it is called that. This is the first one that I understood. Now I know why it is different from other valve configurations. Nobody else showed a diagram. Thanks for the education.
Buick did a Jan. 1953 presentation about its new V8 at the national SAE meeting in Detroit—the published paper is 20 pages of text, illustrations, and charts laying out their “what they were thinking” goals and choices, especially noting everything gained in comparison to their straight-8. We learn that future styling considerations (low/sloping hoods, etc.) made a compact engine desirable, and actually that final production of the engine was delayed due to machine tool shortages (perhaps related to the Korean War restrictions on industry re materials and equipment). They take pride in a spark plug more centrally located than in any competing engine, and talk about the reasons that they’re satisfied with valve size (in combination with cam, intake/exhaust passages, etc.). Fascinating! (“The design also makes possible a common horizontal gasket surface for the rocker-arm cover and for the intake manifold, which simplifies machining, and, even more important, greatly reduces the sealing problem at these critical points.”) Paul, I’ll e-mail a copy to you momentarily; I’m a Ford guy, and so I’ve learned plenty from you here!
We learn that future styling considerations (low/sloping hoods, etc.) made a compact engine desirable
Sure, but as long as Buick was going to share Fisher bodies with Cadillac and Olds, that really wasn’t ever going to be a real factor.
There is no question that the Buick was commendably compact. One can see that by comparing the cross sections of the Buick and Cadillac V8s up in my post. It was decidedly more compact.
But given the trend in cars getting longer and wider, that was all for naught, eh? The Buick V8 looks positively lost in the engine compartment of any full sized Buick.
The Air Force used a Buick V8 to start the engines on the SR-71.
There are two Buick engines in the original start carts for the SR-71.
As far as the Buick drag engine with the exhaust routed out of the intake ports, Ford flathead V8’s were also modded like that. Gotta be a real diehard fan or marching to a different tune. Better engines available that put out more power for probably a lot less cost.
The SR-71 starter has been discussed and illustrated in prior posts.
I had the two 4-BBL version of this torque monsta Buick 425 cubic inch “Nailhead” V8 in my ’64 Riviera.
The huge chrome, dual snorkel chrome air cleaner and the finned aluminum valve covers were/still are a fine example of automotive beauty; just to open the hood and gaze at.
But driving it was even better!
The steady progression of: the AFB carb’s secondaries coming “online”, then the entire second 4-BBL carburetor opening up and then the downshift from third to second gear of the new-for-1964Turbohydramatic automatic transmission literally would take my breath away.
First time “Shotgun” riders would either be stunned into reverent silence or let our a rebel yell, using words that could not be repeated in polite conversation.
Of the five GM divisions, Buick seemed to be the one that was most successful in avoiding Deadly Sins (the 1986 Buick Riviera that looked way too much like the substantially cheaper Buick Somerset being an exception).
The nailhead V8 could be considered a big part of Buick’s success. Was it a great engine? Hardly. But, as pointed out in the article, it worked well in the vehicles for the demographic that bought Buicks. In fact, it could be said that the nailhead was the embodiment of the old industry adage “American auto consumers might talk horsepower, but they drive torque”.
Note: The caption of the photo of the engine swap identifies the recipient as a Chevy. It looks like a ’53-54 Pontiac to me.
I’m thinking early split windshield Olds 76 or 88 (smaller ‘Chevy’ body) with Buick grille (says ‘Buick’) and Olds wheelcovers to make a lighter weight ‘Buick’ ‘funny car’ for racing… maybe has a Hydramatic 4 speed automatic tranny… maybe a B&M Hydro version…
Excelente explicación y comentarios adicionales.
Yo tuve en la adolescencia un Buick Super Riviera Dynaflow 1958. Era un auto ya de 25 años y fue un excelente vehículo que me introdujo en el mundo de los autos antiguos.
Comparto con todos, los comentarios positivos hacia el motor Nailhead y a la transmisión.
El coche fue destruido por mecánicos incompetentes años después.
Considero que incluso ese vehículo pido haber sido más fino y confiable que un Rolls Royce de la época.
Translation of Daniel’s comment above:
Excellent explanation and additional comments.
I owned a 1958 Buick Super Riviera Dynaflow as a teenager. It was a 25-year-old car and it was an excellent vehicle that introduced me to the world of vintage cars.
I share with everyone, the positive comments towards the Nailhead engine and transmission.
The car was destroyed by incompetent mechanics years later.
I consider that even that vehicle I wish to have been finer and more reliable than a Rolls Royce of the time.
The valves of the 401 Buick at 1.875″ x 1.5″ aren’t much different than Chevy SBC ‘400’ (actually, also, 401″) of 1.94″ x 1.5″… First year, 1970, SBC 400 w/ 2 bbl. carb. and 9:1 rated 265 HP. (same HP as last 2 bbl. carb. BBC 396″/402″)… but much milder 194/202 durations cam (184/194 in trucks). Although the Buick valves were prolly much more shrouded by the chambers design/size. The stock cam durations used in Buick 401’s were prolly what we would call a 400 HP cam nowadays for a SBC…
Buick had a better valves layout in the old OHV straight 8. The ’38 Buick with 320″ straight 8, 3 speed manual, and little 2 door body was a bit of a ‘muscle car’. There’s one that shows up at our local cruise nights pumping 200+ HP now…
Besides the early 50’s Buick hemi, they also had a conventional 215″ aluminum V8 in 1951 concept cars… a Roadmaster… but haven’t seen the exact valve layout of it… maybe conventional, maybe a nailhead… on nailheads, looking from the front, the pushrods and valve stems actually cross as an X… instead of being parallel.. Buick may have been considering a 4 valves per cylinder (small valves not a problem) pentroof engine with forked rocker arms which I think was seen in some earlier WWII engines… maybe even earlier racing engines… I always assumed the ’61 – ’63 Buick/Olds 215’s had rocker arms instead of stud mounted rockers because of its ear;y 1950’s, maybe late 1940’s design history… I think the rocker arms are also aluminum… ALCOA was pushing automakers to make aluminum engines… even a few aluminum Chrysler Slant Sixes went into production…
I believe the Honda Silver Wing V2 motorcycle engines are pushrod 4 valves per cylinder. Since the cylinders stick out sidewise, they went center cam pushrod OHV because OHC would make the engine too wide/tall…
The new Chrysler Hemis also have nearly horizontal roller lifters but some get poor oiling to the needle bearings, they fail, and the lifter roller cuts a groove in the cam lobes by 100-150K miles, especially on valve deactivation versions… also, the Stellite valve seats fall out of the aluminum heads by that mileage destroying the engine, especially if the engine has ever overheated… the earlier all iron Magnum 360″/5.7L makes a more dependable, longer lasting truck engine, often showing little wear at 500,000 miles…
Child TV Tommy Ivo (and young Kurt Russell) can still be seen today in old westerns shown on TV old westerns channels.
My brother had a 63 Lesabre 4 door sedan with a 401 4bbbl. It had enough torque taking off in low to break the diff and put a hole in the case.
An interesting fact about nail valve engines was that the cam lobes were centered under the lifters. Most OHV engines had the cam lobes slightly offset from the lifter base to cause them to rotate a little each cycle to maintain an even wear pattern.
Chevy with ‘W’ engine (409), Ford with similar design, and Buick with nailhead all eventually realized they needed to go with conventional design as used by Pontiac, Olds, Chevy, and Cadillac to make good HP with good MPG while avoiding detonation…
Actually, with Buick’s adoption of the THM-400 three-speed automatic with a torque converter, The gobs-of-torque Nailhead was no longer necessary. The Dynaflow was essentially in high gear all the time, and the Nailhead could supply the massive torque that the Dynaflow required to get a heavy car moving.
What brought me here: the song “Nailhead” by The Kings of Nuthin’. Now I understand the song a lot better. I’m kind of MOPAR guy myself. My Roadrunner demands it.