From CarCraft: (complete article here) http://www.carcraft.com/thehistoryof/65502/ The History of... History of the Buick Nailhead A Small But Loyal Following Of Gearheads Collect, Build, And Race Nailhead-Powered Buicks By Tony Nausieda Photography: Tony Nausieda As is the case with other oddball engines, there is a small but loyal following of gearheads who collect, build, and race nailhead-powered Buicks. While they were never serious performance contenders in stock form, the early nailhead Buicks powered many street rods, drag cars, road-race machines, and even Bonneville top-speed racers during the late 50s. A 401ci nailhead powered the first A-body Buick GS and paved the way for the dominating Stage 1 powerhouses of 1969-1974. Most of todays nailhead-powered rides, though, are street rods or stock restorations. In other words, theyre rarely chosen for high-performance use anymore. We dug decades-deep into the Car Craft archives and found a wealth of nailhead history in the form of photographs and magazine articles. Whether its the outspoken Tommy Ivo running four nailheads on his Showboat dragster, or the hard-core drag racer who reversed his nailheads intake and exhaust ports to get better airflow, the theme of late 50s and early 60s speed scene was anything goes. Along with the Chrysler Hemi and Y-block Ford, gearheads of the day embraced the Buick nailhead as one of the best foundations for making their cars outrageously fast. Stockers The nailhead was introduced for the 53 model year as a replacement for the straight-eight engine. The basic design of this engine is generally attributed to Buick engineer Joe Turner. Displacing 264 or 322 ci, the new Buicks were state-of-the-art, powerful, overhead-valve V-8s. The 322ci version was designed with an industry-leading 8.5:1 compression, and churned out a respectable 188 hp. Gearheads nicknamed the new V-8s nailvalve or nailhead motors because the intake and exhaust valves were relatively small in size and installed vertically. The engines odd valve orientation and pent-roof combustion chamber design gave the engine its distinctive upright rocker covers, which made the nailhead significantly narrower than other V-8 designs. But the convenient packaging wasnt without compromise. The head design allowed decent-flowing intake ports, but the extra bend in the exhaust ports made for a restrictive design. But that didnt compromise the intended purpose of this motor. In the words of Dennis Manner, a former Buick Powertrain engineer, These engines were designed to provide smooth, powerful acceleration to move heavy cars. They made incredible torque at the expense of high-rpm horsepower, but horsepower wasnt our goal. For the 57 model year, Buick bumped up the nailheads displacement to 364 ci, as the cars themselves were growing bigger and heavier. The 364 was a very different engine than the earlier small-cube nailheads, so few parts interchange with later-model 364/401/425 engines. With a stout 9.5:1 compression ratio, the new 364 was good for 250 hp. If that wasnt enough motivation for your driving style, Buick engineers brought forth an optional 10:1 version that brought power output to an even 300 hp. While 300 hp is the baseline for a tow rig these days, remember that even the fuelie 283ci small-block Chevys were only good for 283 hp in 1957. A 325hp 401ci nailhead was introduced for 1959 in the high-line Invicta and Electra models with the odd moniker Wildcat 445, referring to 445 lb-ft of torque. The Wildcat name and torque output would designate all nailheads built through 1966. After all, the nailhead was a torque motor, so why not call it by what it does best? You might be surprised to learn that 59-61 401s were fitted with one of the most radical factory cam grinds of their day. It featured 299/290 degrees of duration and 0.441/0.439 inches of lift at 0.050 on the intake/exhaust, ground on a 109-degree centerline. This grind helped air flow through the restrictive head design and small 1.875/1.5 intake/exhaust valves, but left the stodgier Buick owners asking their dealers why their luxury liners ran so rough. The LSA was toned down to 114 degrees for 62, but the rump-rump Buick idle (as quoted from Hot Rods 65 GS road test) had already become famousor, depending upon who you ask, infamous. The 63 model year marked another upgrade in nailhead performance with the introduction of the Wildcat 465, a 340hp 425 ci, available as an upgrade for the first-year Riviera. It shared the 401s steel crank, but was punched out to a larger bore (4.31 inches versus the 401s 4.19-inch bore). The 425 option was extended to the big Buicks in 64, as was an additional 360 hp Super Wildcat version. This beast came loaded with two Carter four-barrel carbs topped with a gorgeous ribbed chrome air cleaner. Neither the 425 nor the dual-quad setup was ever factory installed on the 65-66 A-body Skylark GS, but gearheads often bought all the necessary goodies from the parts counter to slap on their Larks. It seems Buick offered too little, too late to catch the musclecar train with nailhead power. The 65 and 66 A-body GS cars came standard with the 10.25:1, 325hp 401. Only a very limited number of 66s were ordered with an optional 340hp 401 fitted with 11:1 pistons and a Quadrajet carb in lieu of the standard Carter AFB. Road tests of the stock 65-66 GS show mid-15-second quarter-mile performance on par with most other base-engine musclecars of the era, but the lack of a mass- produced hi-po engine option kept most drag-happy youngsters out of Buicks performance offering. Nailhead Power The nailhead began to trickle down into the greasy hands of Hot Rodders in the mid-50s, which is when development of Buick speed parts really took off. Speed companies like Weiand and Offenhauser, whod been at the forefront of flathead Ford performance, began casting trick multi-carb intakes and finned aluminum dress-up parts. Bobby Hedman started making headers to bolt up to nailhead exhaust flanges. Bellhousings were designed and produced to back up nailhead engines with strong manual gearboxes. Hilborn engineered a trick mechanical fuel injection system that could keep even the rowdiest Buicks fed. The advent of the small-block Chevy put a dent in Buick go-fast interest, but the nailheads robust forged crank and rods could take repeated beatings that would scatter a stock Chevy motor. And the narrow packaging of the nailhead made it even more practical for sandwiching between the fenders of a roadster. Digging through the Car Craft photo archives, we found one Buick-powered roadster for every four at NHRA drag racing events through the late 50s. Even the SCCA road racing events were shaken up with Buick-powered corner carvers, presumably because of the nailheads relatively light weight among big-inch motors. Sponsored Links Edelbrock Intake Manifold Save Big on all Performance Parts! Free Shipping - Huge Online Catalog www.speedycarparts.com Bid on Edelbrock Find Edelbrock Carburetors on eBay at huge discounts. Aff www.eBay.com Performance Parts Save Money We sell for less than Mail Order Catalog Companies! WWW.RaceParts2000.Com What seemed to separate the nailhead-powered cars from the rest, though, was the variety, ingenuity, and downright weirdness that Hot Rodders had developed to go faster with Buicks. We found cars that were rigged with every possible multi-carb setup under the sun. Six Strombergs, two WCFB four-barrels, three deuces, and everything in between. A few of the more serious drag cars sported huge chain-drive Roots-style blowers. A wild NHRA A/D drag roadster was equipped with twin McCullough centrifugal superchargers. But one of our favorite nailhead-powered cars was a dragster photographed at the 58 NHRA Nationals. This Buick was squeezed with a crank-driven blower, which fed pressurized air into...the exhaust ports? That would explain why the exhaust was ducted straight out of the intake. This would be possible provided the cam was re-ground to operate the valves correctly. We dont know how this reversed-port deal improved the heads efficiency, but it sure looks wild. By the time we hit the 60s archives, though, the nailhead photos were few and far between. The speed aftermarket had moved toward the Chevy and Chrysler camps because theyd become the motors of choice with Hot Rodders. One glaring exception to the rule was TV Tommy Ivo and his insane multi-nailhead-powered dragsters that set precedents of punishment upon the racing scene. Ivo had successfully raced a single-engine Buick dragster, gaining notoriety by running the fastest gasoline-powered e.t. of the 58 season9.16 seconds. He accomplished all this while juggling an acting career. Hes been in nearly 100 movies and twice as many television shows. His popularity and personality made TV Tom an awesome frontman to advertise nailhead power. Buick never really got involved in the effort, or any racing efforts, for that matter, but Ivo kept making his nailheads go faster and faster. When the NHRA outlawed fuel, he drafted plans for a dragster with twin engines not mounted in series, but side-by-side. The twin 464ci nailheads were coupled through flywheel ring gears, so one motor needed to run backwards. Problem solveda special cam was ground for the reverse-rotation motor, and the cam gear was revised to spin the oil pump and distributor in the correct directions. Tommy done good; the double-Buick monster became the first sub-9-second car, and ran a best of 8.29 at 193 mph. Ivo told us that the weirdest part of the twin- engine car was watching the front end rise and fall under load instead of torquing over. What could be any better than a twin-engine dragster? How bout raising the ante by two nailheads? Ivo and fellow racer Kent Fuller built the four-wheel-drive, four-engine Showboat dragster, which was immediately outlawed by the NHRA after its completion. Instead it was match-raced around the country, driven by Ivos former tire wiper crew assistant, Don Prudhomme. Its a great story, and it sure made for great publicity for the Buick V-8. But not enough publicity to pry Chevy motors from the hands of Car Crafters. Even with the 401-powered Skylark GS cars, there was little mention of performance upgrades through the aftermarket. The few examples we found had the nailheads running really impressive numbers after a scant number of mods. Hot Rod tested a mildly warmed over 66 Skylark GS hardtop and ran 14 flat at 101 mph. They claimed to have installed only Goodyear 9.5-inch slicks, 4.30 gears, headers, and drag springs. Another Hot Rod article from the May 65 issue (where was Car Craft?) ran a segment on Los Angeles area dealer-sponsored Skylark GS drag cars. Reynolds Buick, of West Covina, sponsored an automatic-trans 65 GS driven by Lennie Kennedy. The engine had been blueprinted to stock specs (were still not sure what that means), the heads were treated to a performance valve job, Hooker headers were added (and uncorked at the strip), 4.30 gears were fitted, and the rear suspension was fitted with Casler recap tires and a 4.30-geared posi. Result: 13.42 at 104.46. So why was the nailhead dropped for 1967? Everyones got a theory. Some say a new Buick chief engineer wanted his own engine in Buick cars. Well probably never know those deep, dark GM secrets, just like we cant figure out the Pontiac Aztek. Nevertheless, were proud to have a nailhead-powered Buick on the road 35 years after the last of em rolled off the line. But youd think that the 35 years of technology would help us get our 66 to run at least as fast as some of the modded cars of the era. Special thanks go out to everyone on the Nailhead Mailing List who helped supply information for this article. Theres no better one-stop source for nailhead information. Check it out at http://groups. yahoo. com/group/BuickNailHead)
The Nailhead is a very tough, powerful, and durable motor. It has been virtually ignored where high performance parts are concerned. Perhaps as time goes by, and the supply of other engines dry up, the demand for Nailheads will increase........thereby creating a demand for well deserved aftermarket performance parts. My old 425 had well over 200,000 miles on it before I replaced it with a fresh one. The last time I drove it before removing it from the car, I really pushed that thing..........she had 3 broken rings, nearly 3 times too much piston clearance, very little oil pressure at idle, and smoked like hell at full throttle.........and still yet on that last drive I took her up to over 60 MPH in first gear.......she was revving over 6,500 RPM.........I just held her there pinned, valves floating, and she just wouldn't give. Now THAT'S reliability. I dare someone to do that with another type of high mileage motor...........yes, I am crazy but I love my Nailheads. :bglasses:
Nailheads are the Best Nailheads over the Years have Proven Themselves as a Significant Powerplant in both the Automotive and Marine (Gray Marine Engines) Industry. They have Proven to be Reliable, Versatile and powerful. Almost bullet proof. They are Torque Engines and from 1953 to 1966. They were the powerplant of choice from Buicks, to Chevy and GMC Trucks, and CrissCraft and numerous other Boat Manufacturers. And 50 Years Later and considered obsolete in 1967, are Still a Topic of Conversation, and a Very Much Soughtafter Nostalgic Powerplant
Great info, but just to be on the anal side, there never was a 401 in any "A" body, it's a "400" at least that is what GM wanted us to believe. p Yep, there are few cooler looking motors, that's for sure.
My only wish on these motors is a cast iron timing cover with an iron water pump that has a heavy duty greasable bearing. I know, more weight, but reliability is what these engines are all about. Believe it or not, I have a cast iron water pump core that fits my motor, but I prefer not to use it........one ear is broken on it. I wonder how many of these are out there?:Brow:
My Riv (425) sat in a barn for 15yrs untouched. I bought it, loaded it on a trailor and took it home. Checked over everything, finally found a carb for it, and after getting the carb right, it fired up no problem.
all my nailhead water pumps are cast iron. i have a couple of the 5 blade impellar and a couple of the 3 blade non a/c type. didnt know there was an aluminum type out there. Bob
