Building a Better Buick, Part I
Performance-Rebuilding a Buick Nailhead
From the February, 2009 issue of Rod & Custom
By The Rod & Custom Staff
Photography by Michael Breeding, The Rod & Custom Staff
We contacted Kanter Auto Products...
We contacted Kanter Auto Products and ordered a complete rebuild kit for a 401 Buick engine. The kit included pistons, rings, bearings, a camshaft, lifters, rocker arms, springs, pushrods, a timing chain, freeze plugs, and a gasket kit.
The rocker arms and shafts...
The rocker arms and shafts were rebuilt by Rocker Arm Specialists and are adjustable for superior fine-tuning. The company does a magnificent job of rebuilding the shafts, and they're delivered ready to bolt on.
We ordered a new aluminum...
We ordered a new aluminum water pump from Classic Buicks. It's a very efficient pump. It's lightweight and can be polished for a nice appearance.
The Kanter Auto Products kit...
The Kanter Auto Products kit comes complete with a full set of Best gaskets.
The Kanter Auto Products kit...
The Kanter Auto Products kit comes with an oil pump rebuilding kit that includes the two rotors and all the gaskets necessary to get the pump working perfectly.
We also wanted to improve...
We also wanted to improve the engine's performance and appearance, so we ordered an Offenhauser dual-quad high-rise intake manifold and had it polished by Joe Stubblefield Polishing in Paramount, California.
Edelbrock 500-cfm carburetors...
Edelbrock 500-cfm carburetors are going to be used along with a linkage kit and a pair of small air cleaners. These will be used under the O'Brien Truckers finned aluminum air cleaner cover.
Offenhauser also makes a very...
Offenhauser also makes a very attractive set of finned aluminum valve covers for the Buick nailhead. These highly polished valve covers look great on the engine, especially when they are detail-painted to match the block.
In keeping with the '60s appearance...
In keeping with the '60s appearance of the engine, we ordered a finned aluminum valley cover from Mooneyes that will match the valve covers. It comes in a natural cast finish, so it was taken to Joe Stubblefield Polishing.
The front pulleys were also...
The front pulleys were also chrome-plated to improve the engine's appearance. These were done by Astro Plating in Van Nuys, California.
We contacted O'Brien Truckers...
We contacted O'Brien Truckers and ordered an 18-inch-long finned aluminum air cleaner and a set of finned aluminum spark plug covers. This Buick engine will really have a nice early '60s appearance.
We delivered the engine to...
We delivered the engine to the people at Jim Grubbs Motorsports in Valencia, California, where they started by hot-tanking and inspecting the block. When they determined it was in good condition, they began the boring process. This machine bored the engine just slightly under the desired 0.030 overbore.
When the boring ws completed,...
When the boring ws completed, the cylinders were honed to the exact specifications for the pistons.
It's always advisable to deck...
It's always advisable to deck the block to ensure a flat mating surface for the heads. Because of the Buick intake manifold design, only a minimal amount of material should be removed.
The heads were also machined...
The heads were also machined for a flat mating surface. Again, care should be taken to remove only enough material for a flat surface.
The heads were completely...
The heads were completely rebuilt, including the installation of new valve guides and bronze inserts.
The bronze inserts were machined...
The bronze inserts were machined for the new valves and oil seals. This photo also shows that the nailhead engines are equipped with large square intake ports for good fuel flow. The runners are short for good fuel velocity.
Any time you rebuild a pre-'70...
Any time you rebuild a pre-'70 engine of any type, it's always a good idea to install hardened exhaust valve seats. Here we see Jim Grubbs Motorsports installing the hardened seat.
The seats were machined to...
The seats were machined to the correct angle with this machine, then finished off with stones to get a multiple-angle high-performance seat. In this photo, you can see how close the valves are, so it's almost impossible to increase the valve size of the engine. Buick uses a 1.94-inch intake valve and a 1.50-inch exhaust valve. Sound familiar, Chevy fans?
The valves in this engine...
The valves in this engine were actually in exceptionally good condition, so they only needed some mild resurfacing of the mating surface to be reused.
Jim Grubbs Motorsports reconditioned...
Jim Grubbs Motorsports reconditioned the rods and resized them. A small amount of material is removed from the cap, then they are machined for the exact tolerances needed.
After the rods have been reconditioned,...
After the rods have been reconditioned, the engine can be balanced. The rods are weighed to find the lightest one, then the other rods will have to be machined to match its weight.
Here the piston-side of the...
Here the piston-side of the rod is being weighed. When weight is removed from the rod, it will be removed from either end of the rod as needed so all of the rods match end to end.
The pistons are also weighed...
The pistons are also weighed to find the lightest one. When it's found, the pistons are machined to match that weight. There are small pads inside the pistons where weight can be removed.
Since it would be impossible...
Since it would be impossible to balance the crank with the rods and pistons attached, bob weights are installed on the crank that match the weight of two pistons, two rods, two wristpins, two rings, and two bearings per journal. With the bob weights, the harmonic balancer, and the flexplate attached, the crank is spun on a computer balancer to find where the unit is out of balance. Weight will be removed where necessary to get the crank into perfect balance.
Now it's time to install the...
Now it's time to install the piston on the rod. The assembly is laid out and checked to make sure the piston and rod are correctly positioned before they are assembled.
Piston assembly requires a...
Piston assembly requires a special machine that heats the end of the rod to expand the journal to the point where the piston pin will slide right through. The rod end is heated, then removed, and the pin is forced through with the tool shown. When the rod cools down, the pin becomes stationary in the piston.
The final part of the machining...
The final part of the machining process is head assembly. Here we see the springs being installed on the valves. The Kanter kit came with new keepers. In the second installment, we will tackle the assembly of the engine.
If you look closely inside...
If you look closely inside this cam journal, you will see a groove. Buick cams use a snap ring to keep the cam in place, and if you try to pull the cam out without removing the ring, you will probably ruin the cam and the block. The rear cam plug will have to be removed to gain access to the ring.
Another problem you can run...
Another problem you can run into is that there is a hidden hole behind the rear block plug. Both have to be plugged, or you will have no oil pressure.
If you're looking for an alternative engine for your street rod that's nostalgic in appearance and runs strong, you might want to consider a nailhead Buick engine. They were extremely popular in the late '50s and early '60s because they delivered plenty of power and torque, were compact in size, and (with an ample supply of appearance items) they looked great in a street rod or custom. Many notable cars in the early years were Buick-powered, such as Tommy Ivo's T-bucket, Tony Nancy's '29 Ford roadster race car, and Tommy Ivo's four-engine dragster, just to name a few. The Buick nailhead V-8 engine was introduced in 1953 and was offered in a 322ci displacement.
In 1954, Buick offered two engine sizes: a small 264 V-8 for the Special series body style which was available in 143- or 150hp versions. The 322 engine was also available for the Century and Roadmaster body styles in 195- or 200hp versions. The 322 was carried over in 1955 and 1956 with horsepower increases. In 1955, the horsepower topped out at 235, and in 1956 it increased to 255. In 1957, the Buick nailhead grew to a 364ci displacement with a top rating of 300 hp. The 364 engine size continued in 1958, but was increased in 1959 to a 401ci displacement producing 325 hp. The nailhead finally topped out at 425 ci in the Riviera model in 1964 and was developing 340 hp. Buick continued to use the nailhead design until 1966, making them plentiful in auto wrecking establishments.
We picked up this 401ci Buick engine which came out of a Skylark GS at Memory Lane in Sun Valley, California. The company generally has a good supply of nailhead engines, although the 425 GS dual-quad engines are scarce, and expensive if you can find one. Since the popularity of these engines has increased, parts availability is also better than it has been in the recent past. We got a complete rebuild kit for this engine from Kanter Auto Products that contained rings, bearings, pistons, rocker arms, pushrods, a new camshaft and lifters, a timing chain, an oil pump rebuild kit, and a gasket kit. The company also offers parts for other antique engines, including Chrysler Hemi and wedge engines, Cadillacs, Oldsmobiles, flathead Fords, and many other outdated engines.
The problem Buick performance enthusiasts will find is that all of the major cam companies have discontinued manufacturing hotter-than-stock camshafts for the early Buick engines. There is one bright spot, however. Classic Buicks offers five different selections of Kenne-Bell camshafts for increased horsepower, including one solid lifter cam designed for racing applications. We selected a KB Mark 2A hydraulic camshaft featuring a 0.475-inch intake lift and 0.488-inch exhaust lift with 270 degrees intake duration and 278 degrees exhaust duration. The cam is cut on a 110-degree lobe center and offers increased power from 1,400 to 6,000 rpm. The rocker arms and shafts were custom rebuilt by Rocker Arm Specialists in northern California, and they were redesigned with rocker arm adjustability.
In order to enhance the Buick engine's appearance, we are equipping it with an Offenhauser dual-quad intake manifold, two Edelbrock AFB carbs, Offenhauser finned aluminum valve covers, Mooneyes valley pan and breathers, and O'Brien Truckers finned aluminum spark plug covers and 18-inch air cleaner. We also ordered an aluminum water pump from Classic Buicks, which was polished along with the stock aluminum timing chain cover. When we are finished, this will also be a very attractive engine that should catch the attention of many street rodders.
The machine work for the engine was performed by the talented folks at Jim Grubbs Motorsports in Valencia, California. The engine was bored, the crank was ground, and the heads were rebuilt. The reciprocating assembly was balanced for smooth performance and durability. We'll give you a quick overview of what was done to the Buick to get it ready for assembly and detailing.
Classic Buicks Inc.
4632 Riverside Dr.
Astro Plating and Polishing
15236 Erin St.
2700 California St.
76 Monroe St.
Joe Stubblefield Polishing
Rocker Arm Specialists
19841 Hirsch Ct.
11311 Pendleton St.
Jim Grubbs Motorsports
28130 Crocker Ave.
Offenhauser Sales Corporation
P.O. Box 32218