413 Max Wedge
The 413 Max Wedge exists because Chrysler president Lynn Townsend asked his teenage sons why Dodges and Plymouths had no presence on Woodward Avenue. His boys told him the truth: Mopars weren't part of the action. Townsend called the engineering department. A man named Tom Hoover answered the phone. Hoover had been a member of the Ramchargers, the infamous club of Chrysler engineers who drag raced their own cars on company time and personal time alike. Townsend gave Hoover full corporate support and a budget. By May 1962, the Maximum Performance 413 was in production. The first production car to break the 12-second barrier was a 413 Max Wedge Plymouth Savoy called the "Melrose Missile," driven by Tom Grove, running 11.93 at 118.57 mph on July 15, 1962, at Fremont Drag Strip. The proto-muscle car had arrived.
The Max Wedge started with the cross-ram intake. Tom Hoover had experimented with long-runner intake designs while building the Ramchargers' "High and Mighty" 1949 Plymouth, which used a tunnel-ram-style manifold extending through the hood. From that experiment, Chrysler developed the Long Ram Induction system (carburetors on opposite sides above the valve covers) for the 1960-1961 413. The Max Wedge compressed those long runners into a short-ram design: a compact aluminum manifold with 15-inch internal runners, two Carter AFB four-barrel carburetors (approximately 600 CFM each) mounted on opposite corners, and the manifold acting as the lifter valley cover. The short runners improved high-RPM horsepower over the long-ram's low-end torque emphasis. Chrysler had distilled four years of cross-ram competition experience into one casting.
The Max Wedge heads had 25 percent larger intake and exhaust ports than the standard 413, no heat crossover passage, 2.08-inch intake valves and 1.88-inch exhaust valves (1/8-inch larger exhaust than stock), reshaped combustion chambers, and restructured deck surfaces for increased clamping rigidity with stainless steel head gaskets. The camshaft: .510-inch lift, 300 degrees of duration, solid mechanical lifters. Double valve springs. Nodular iron adjustable rocker arms. Tubular pushrods. Inside: shot-peened connecting rods, forged pistons at either 11.0:1 (410 HP at 5,400 RPM) or 13.5:1 (420 HP at 5,400 RPM), hardened crankshaft journals, heavy-duty copper/lead bearings, high-volume oil pump, and a baffled oil pan. Upswept cast-iron exhaust manifolds with individual passages flowing into 3-inch header pipes. Double-breaker distributor. Deep-groove pulleys. Low-power-absorption water pump.
For 1963, Chrysler bored the 413 to 4.25 inches and created the 426 Max Wedge. The 426 ran 415 HP (11.0:1) and 425 HP (13.5:1). The 1964 Stage III 426 dropped to 12.5:1 maximum compression but maintained 425 HP. Then the 426 Hemi arrived for 1964 as a race-only engine and the Max Wedge program ended. Total 1962 Plymouth Super Stock 413 production: 190 cars. Only 23 are known to survive. The Max Wedge was the engine that made Dodge and Plymouth relevant on the drag strip, the engine that preceded the Hemi, and the engine that exists because a corporate president's teenage sons told him the truth about his own cars on Woodward Avenue.
