Pierce-Arrow Society Feature Article 

1926 Dual-Valve Six Magazine advertisement
Series 33
Dual-Valve Six

As the Roaring Twenties began, the Pierce-Arrow line was completely overhauled. The basic line of three chassis, the 38hp, the 48hp, and the huge 66hp, were replaced with a single product. First introduced in 1920 as the Series 32, minor changes in late 1921 transformed the car into the Series 33. The Series 33 remained Pierce-Arrow's flagship model through the mid-twenties, continuing in production through early 1926. It was replaced in 1927 and 1928 with the Series 36, which shared much of the same chassis, but had new sheet metal.

1923 Pierce-Arrow Series 33 French Landau
1923 Pierce-Arrow Series 33 French Landau

Most of the old management at Pierce-Arrow was gone and the new management wanted to simplify the product line. The single chassis was initially offered with ten body styles, although the number of factory body styles crept up over the years. The cast aluminum bodies of the earlier cars were replaced with bodies made of 14-gauge aluminum over a Northern white ash framework. Steel fenders and hoods were used. Many of the smaller body components, such as the instrument panel and glove boxes, window moldings, and the firewall were still made of cast aluminum.

1926 Pierce-Arrow Series 33 7-Pass. Touring
1926 Pierce-Arrow Series 33 7-Passenger Touring

All of the bodies were mounted on the same 138 inch wheelbase chassis. Prices were quoted for both complete cars or extra bodies, allowing the owner to have an open body for summer use and a closed body for winter use. The hood and front fenders were standard across all body styles, except the Runabout, which could not be interchanged with any of the other bodies. The Runabout featured a highly arched cowl, which required a completely different hood and instrument panel. The steering column was mounted at a more rakish angle and the Runabouts had a slightly higher gear ratio.

Series 33 Standard Body Styles
  • Open Cars
    • 2-Passenger Runabout - with rumble seat
    • 4-Passenger Touring
    • 6-Passenger Touring
    • 7-Passenger Touring
  • Closed Cars
    • 3-Passenger Coupe
    • 4-Passenger Coupe-Sedan
    • 4-Passenger Sedan
    • 7-Passenger Sedan
  • Formal Cars
    • 6-Passenter Landaulet - open-front town car with collapsible rear quarter
    • 6-Passenger Brougham - open-front town car
    • 7-Passenger Limousine - enclosed rear compartment and an open chauffeur's compartment with fixed roof.
    • 7-Passenger French Limousine - a slightly larger open-front town car
    • 7-Passenger French Landau - a slightly larger open-front town car with collapsible rear quarter
    • 7-Passenger Enclosed-Drive Limousine
    • 7-Passenger Enclosed-Drive Landau
1925 Pierce-Arrow Series 33 Coupe-Sedan
1925 Pierce-Arrow Series 33 Coupe-Sedan

The Series 33 was powered by the Pierce-Arrow Dual-Valve Six, a 414 cubic inch, six cylinder, T-head engine using four valves per cylinder and two spark plugs per cylinder. The two camshafts were located in the aluminum crankcase and were gear-driven off the crankshaft. The Delco dual-ignition system used two coils mounted on the firewall and a single dual-distrubutor unit with two distributor caps to fire the spark plugs. A modification in 1924 replaced the distributor with a unit having a single 12-tower cap. Switches on the instrument panel allowed the engine to be run on either set of spark plugs, or both sets simultaneously.

1923 Pierce-Arrow Series 33 Limousine
1923 Pierce-Arrow Series 33 Limousine

Gasoline was delivered from the rear-mounted tank to the Pierce reed-valve carburetor via a pressure system. A hand pump mounted on the instrument panel was used to initially pressurize the tank; a camshaft driven pump maintained the pressure while driving. The oil system of the Series 33 cars featured a vacuum regulation system to deliver more oil when the engine was running under a load and less oil when the car was coasting.

Initially, the Series 33 cars were delivered with 2-wheel mechanical brakes. Later, 4-wheel brakes were offered, first as an option and later as standard equipment. Two spare tires were standard equipment, mounted either in the front fenders or at the rear. A Kellogg tire pump mounted on the transmission provided air for even more tire problems.

1923 Pierce-Arrow Series 33 Runabout
1923 Pierce-Arrow Series 33 Runabout

As with earlier Pierce-Arrows, the luxury and attention to detail was evident. The radiator shell and most other bright work was solid German Silver. Two large, locking glove boxes were provided in the instrument panel and many of the bodies featured other locking storage compartments. All locks, including ignition, hood, spare tire, doors, glove boxes, and storage compartments were keyed the same. Steering wheels were made of walnut and closed cars used mahogany window moldings. The list of tools delivered in the locking storage compartment under the front seat included not only the jack & rim tools, a collapsible pail, cans of oil and grease, but enough other tools to equip a small machine shop! 

Several Series 33 Pierce-Arrows have survived and frequently attend our Annual Meet. To learn more about these cars, we invite you to join the Pierce-Arrow Society!

Pierce-Arrow Series 33 Specifications
Bore & Stroke 4" x 5.5"
Cylinders 6
Displacement 414.7 cu.in.
Valves Four per cylinder
Intake on left; exhaust on right
Carburetor Pierce-Arrow -- water jacketed for warm-up
Ignition Pierce-Delco - 2 spark plugs per cylinder
Fuel System Pressure feed from 26 gallon rear-mounted tank. Triumph magnetic level gauge mounted on tank; tank pressure gauge mounted on instrument panel.
Tires 33 x 5
Goodyear, Goodrich, Firestone or United States
Firestone Quick Detachable rims
Wheelbase 138"
Weight 4350 lbs. (Runabout)
5060 lbs. (Enclosed Drive Limousine)
Price Open Cars:    $5250
Closed Cars:  $7000 +
Est. Production 7000