James Kraus
1961 Pontiac Catalina with the original 8-Lug wheel; introduced mid-1960.
American cars of the 1960s were certainly not renowned for their braking prowess. Except for a handful of exceptions, disc brakes were not widely available until 1967 and the drum brakes provided were generally small in size and nowhere near up to the weight and power of the cars to which they were fitted.
Of the Big-Three manufacturers there were only three brands that took braking seriously early in the decade.
Full-size Buicks featured generously-scaled 12” (305mm) finned aluminium heat-dissipating front drums as standard equipment.
Massive Buick finned-aluminum front drum.
Chevrolet offered a heavy-duty brake option as part of the Corvette Z06 package with finned cast-iron drums, segmented Cerametalix linings, backing-plate air scoops and internal stamped-metal cooling fans.
Corvette Z06 front brake assembly.
Pontiac however, created the most memorable (and outwardly visible) answer to improved drum brake performance by borrowing a page from Panhard’s playbook.
GM Concept Firebird with finned aluminium 6-Lug wheels.
General Motors had been exploring the idea of an aluminium wheel with an integral brake drum in the manner of Bugatti and incorporated them into the 1953 Firebird XP-21 concept. The open wheel design exposed the finned aluminium drum to outside airflow, dissipating heat and helping keep brake fade at bay. The aluminium drums and hollow-centre rims also reduced unnecessary unsprung weight.
Panhard PL 17 with exposed finned aluminium drum and open-centre steel rim.
Meanwhile, Panhard was experimenting with exposed finned drums with bolt-on rims. A DB-Panhard HBR so equipped won the Index of Performance at Le Mans in 1956.
Pontiac, under its new management team of Semon “Bunkie” Knudsen, John Z. DeLorean and Pete Estes began developing GMs Firebird wheel design for production in concert with long-time wheel supplier Kelsey-Hayes.
The finished product featured an 11-inch (280mm) finned aluminium brake drum with an attached 14 x 6” steel rim. The studs connecting the two components were increased in number from six to eight, and were secured with chrome-plated acorn nuts; hence the colloquial term 8-Lug.
Pontiac 8-Lug front (incorporating the hub) and rear finned-aluminium drums.
In addition to achieving their goal of improved braking performance, Pontiac engineers created a visually distinctive and captivating wheel design that would adorn numerous senior Pontiacs throughout the 1960s.
8-Lug open-centre steel rim.
The 8-Lug option (officially marketed as Aluminum Wheels or Aluminum Wheel Hubs and Brake Drums debuted on 1960 Pontiacs and lasted through the 1968 model year, after which it was obsoleted by the increasingly popular front disc brake option introduced for 1967.
1963 Bonneville. Beginning in ’63 a wider trim ring was introduced that extended to the edge of the rim, effectively concealing any requisite balancing weights.
1964 Grand Prix. Beginning in ’64 the outer drum surface was painted black prior to final machining of the fin edges.
1965 2+2. The wheel remained 14 x 6” for ’65, but the drum and shoes were widened for increased swept area.
Cars with 8-Lug wheels came with this balancer plate to allow fitting the open-centre rims to standard mounting and balancing equipment.
A smaller and cheaper cast-iron 8-Lug wheel with a 9-inch (241mm) drum and staggered fins was envisioned for mid-year introduction on the 1966 GTO, but never materialized.
Proposed 8-Lug wheel for GTO from the 1966 Pontiac Performance brochure.
With the front disc brake option just months away, an eleventh-hour decision was made not to tool up the iron version for production.
The 1960s were Pontiac’s glory days, the Wide-Track years that saw the introduction of the Grand Prix, GTO, 2+2 and Firebird. Continuing popularity of the Bonneville and Catalina coupled with the success of the newer models propelled the Pontiac Motor Division into third place in U.S. domestic sales.
1964 Bonneville Brougham with optional 8-Lug wheels as rendered by Art Fitzpatrick and Van Kaufman.
Nothing better represents sixties Pontiac excitement and glamour than these unique, functional and aesthetically alluring 8-Lug wheels, a classic example of form following function.
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